From 5c92ca356a5a0afd05115b6c11a989818140b574 Mon Sep 17 00:00:00 2001 From: Josef 'Jeff' Sipek Date: Thu, 29 Nov 2018 16:57:32 -0500 Subject: [PATCH] tzdata: update to 2018g --- contrib/tzdata/CONTRIBUTING | 25 +- contrib/tzdata/Makefile | 446 ++++--- contrib/tzdata/NEWS | 535 +++++++-- contrib/tzdata/README | 16 +- contrib/tzdata/africa | 215 ++-- contrib/tzdata/antarctica | 5 +- contrib/tzdata/asia | 495 ++++++-- contrib/tzdata/australasia | 136 ++- contrib/tzdata/backward | 4 +- contrib/tzdata/backzone | 52 +- contrib/tzdata/checktab.awk | 9 + contrib/tzdata/etcetera | 4 +- contrib/tzdata/europe | 205 +++- contrib/tzdata/factory | 6 +- contrib/tzdata/leap-seconds.list | 8 +- contrib/tzdata/leapseconds | 31 +- contrib/tzdata/leapseconds.awk | 68 +- contrib/tzdata/northamerica | 48 +- contrib/tzdata/pacificnew | 2 + contrib/tzdata/southamerica | 464 +++++--- contrib/tzdata/systemv | 2 + contrib/tzdata/theory.html | 2449 +++++++++++++++++++++----------------- contrib/tzdata/upstream-version | 2 +- contrib/tzdata/version | 2 +- contrib/tzdata/yearistype.sh | 1 + contrib/tzdata/ziguard.awk | 107 ++ contrib/tzdata/zishrink.awk | 207 +++- contrib/tzdata/zone.tab | 16 +- contrib/tzdata/zone1970.tab | 36 +- contrib/tzdata/zoneinfo2tdf.pl | 1 + 30 files changed, 3651 insertions(+), 1946 deletions(-) rewrite contrib/tzdata/theory.html (86%) create mode 100644 contrib/tzdata/ziguard.awk diff --git a/contrib/tzdata/CONTRIBUTING b/contrib/tzdata/CONTRIBUTING index 716f32b3a3..01336fce7f 100644 --- a/contrib/tzdata/CONTRIBUTING +++ b/contrib/tzdata/CONTRIBUTING @@ -17,15 +17,19 @@ To email small changes, please run a POSIX shell command like 'diff -u old/europe new/europe >myfix.patch', and attach myfix.patch to the email. -For more-elaborate changes, please read the theory.html file and browse -the mailing list archives for -examples of patches that tend to work well. Additions to -data should contain commentary citing reliable sources as -justification. Citations should use https: URLs if available. +For more-elaborate or possibly-controversial changes, +such as renaming, adding or removing zones, please read + or the file +theory.html. It is also good to browse the mailing list archives + for examples of patches that tend +to work well. Additions to data should contain commentary citing +reliable sources as justification. Citations should use https: URLs +if available. Please submit changes against either the latest release in or the master branch of the development -repository. If you use Git the following workflow may be helpful: +repository. The latter is preferred. If you use Git the following +workflow may be helpful: * Copy the development repository. @@ -42,6 +46,12 @@ repository. If you use Git the following workflow may be helpful: git checkout -b mybranch + * Sleuth by using 'git blame'. For example, when fixing data for + Africa/Sao_Tome, if the command 'git blame africa' outputs a line + '2951fa3b (Paul Eggert 2018-01-08 09:03:13 -0800 1068) Zone + Africa/Sao_Tome 0:26:56 - LMT 1884', commit 2951fa3b should + provide some justification for the 'Zone Africa/Sao_Tome' line. + * Edit source files. Include commentary that justifies the changes by citing reliable sources. @@ -67,6 +77,9 @@ repository. If you use Git the following workflow may be helpful: git send-email master + For an archived example of such an email, see + . + * Start anew by getting current with the master branch again (the second step above). diff --git a/contrib/tzdata/Makefile b/contrib/tzdata/Makefile index 4f448d2b49..d56a198fb4 100644 --- a/contrib/tzdata/Makefile +++ b/contrib/tzdata/Makefile @@ -1,3 +1,5 @@ +# Make and install tzdb code and data. + # This file is in the public domain, so clarified as of # 2009-05-17 by Arthur David Olson. @@ -10,9 +12,18 @@ VERSION= unknown # Email address for bug reports. BUGEMAIL= tz@iana.org -# Change the line below for your time zone (after finding the zone you want in -# the time zone files, or adding it to a time zone file). -# Alternately, if you discover you've got the wrong time zone, you can just +# Choose source data features. To get new features right away, use: +# DATAFORM= vanguard +# To wait a while before using new features, to give downstream users +# time to upgrade zic (the default), use: +# DATAFORM= main +# To wait even longer for new features, use: +# DATAFORM= rearguard +DATAFORM= main + +# Change the line below for your timezone (after finding the one you want in +# one of the $(TDATA) source files, or adding it to a source file). +# Alternatively, if you discover you've got the wrong timezone, you can just # zic -l rightzone # to correct things. # Use the command @@ -22,14 +33,14 @@ BUGEMAIL= tz@iana.org LOCALTIME= GMT # If you want something other than Eastern United States time as a template -# for handling POSIX-style time zone environment variables, -# change the line below (after finding the zone you want in the -# time zone files, or adding it to a time zone file). -# (When a POSIX-style environment variable is handled, the rules in the +# for handling POSIX-style timezone environment variables, +# change the line below (after finding the timezone you want in the +# one of the $(TDATA) source files, or adding it to a source file). +# When a POSIX-style environment variable is handled, the rules in the # template file are used to determine "spring forward" and "fall back" days and # times; the environment variable itself specifies UT offsets of standard and -# summer time.) -# Alternately, if you discover you've got the wrong time zone, you can just +# daylight saving time. +# Alternatively, if you discover you've got the wrong timezone, you can just # zic -p rightzone # to correct things. # Use the command @@ -66,7 +77,7 @@ DESTDIR = # TOPDIR should be empty or an absolute name unless you're just testing. TOPDIR = -# The default local time zone is taken from the file TZDEFAULT. +# The default local timezone is taken from the file TZDEFAULT. TZDEFAULT = $(TOPDIR)/etc/localtime # The subdirectory containing installed program and data files, and @@ -75,7 +86,7 @@ TZDEFAULT = $(TOPDIR)/etc/localtime USRDIR = usr USRSHAREDIR = $(USRDIR)/share -# "Compiled" time zone information is placed in the "TZDIR" directory +# "Compiled" timezone information is placed in the "TZDIR" directory # (and subdirectories). # TZDIR_BASENAME should not contain "/" and should not be ".", ".." or empty. TZDIR_BASENAME= zoneinfo @@ -97,9 +108,13 @@ MANDIR = $(TOPDIR)/$(USRSHAREDIR)/man LIBDIR = $(TOPDIR)/$(USRDIR)/lib -# Types to try, as an alternative to time_t. int64_t should be first. -TIME_T_ALTERNATIVES = int64_t int32_t uint32_t uint64_t +# Types to try, as an alternative to time_t. +TIME_T_ALTERNATIVES = $(TIME_T_ALTERNATIVES_HEAD) $(TIME_T_ALTERNATIVES_TAIL) +TIME_T_ALTERNATIVES_HEAD = int64_t +TIME_T_ALTERNATIVES_TAIL = int32_t uint32_t uint64_t +# What kind of TZif data files to generate. +# (TZif is the binary time zone data format that zic generates.) # If you want only POSIX time, with time values interpreted as # seconds since the epoch (not counting leap seconds), use # REDO= posix_only @@ -120,7 +135,7 @@ TIME_T_ALTERNATIVES = int64_t int32_t uint32_t uint64_t REDO= posix_right -# To install data in text form that has all the information of the binary data, +# To install data in text form that has all the information of the TZif data, # (optionally incorporating leap second information), use # TZDATA_TEXT= tzdata.zi leapseconds # To install text data without leap second information (e.g., because @@ -162,7 +177,6 @@ LDLIBS= # Add the following to the end of the "CFLAGS=" line as needed to override # defaults specified in the source code. "-DFOO" is equivalent to "-DFOO=1". -# -DBIG_BANG=-9999999LL if the Big Bang occurred at time -9999999 (see zic.c) # -DDEPRECATE_TWO_DIGIT_YEARS for optional runtime warnings about strftime # formats that generate only the last two digits of year numbers # -DEPOCH_LOCAL if the 'time' function returns local time not UT @@ -189,13 +203,18 @@ LDLIBS= # -DHAVE_STDINT_H if you have a non-C99 compiler with # -DHAVE_STRFTIME_L if declares locale_t and strftime_l # -DHAVE_STRDUP=0 if your system lacks the strdup function +# -DHAVE_STRTOLL=0 if your system lacks the strtoll function # -DHAVE_SYMLINK=0 if your system lacks the symlink function # -DHAVE_SYS_STAT_H=0 if your compiler lacks a # -DHAVE_SYS_WAIT_H=0 if your compiler lacks a # -DHAVE_TZSET=0 if your system lacks a tzset function # -DHAVE_UNISTD_H=0 if your compiler lacks a # -Dlocale_t=XXX if your system uses XXX instead of locale_t +# -DRESERVE_STD_EXT_IDS if your platform reserves standard identifiers +# with external linkage, e.g., applications cannot define 'localtime'. # -Dssize_t=long on hosts like MS-Windows that lack ssize_t +# -DSUPPRESS_TZDIR to not prepend TZDIR to file names; this has +# security implications and is not recommended for general use # -DTHREAD_SAFE to make localtime.c thread-safe, as POSIX requires; # not needed by the main-program tz code, which is single-threaded. # Append other compiler flags as needed, e.g., -pthread on GNU/Linux. @@ -222,14 +241,16 @@ GCC_DEBUG_FLAGS = -DGCC_LINT -g3 -O3 -fno-common \ $(GCC_INSTRUMENT) \ -Wall -Wextra \ -Walloc-size-larger-than=100000 -Warray-bounds=2 \ - -Wbad-function-cast -Wcast-align -Wdate-time \ + -Wbad-function-cast -Wcast-align=strict -Wdate-time \ -Wdeclaration-after-statement -Wdouble-promotion \ -Wformat=2 -Wformat-overflow=2 -Wformat-signedness -Wformat-truncation \ -Winit-self -Wjump-misses-init -Wlogical-op \ -Wmissing-declarations -Wmissing-prototypes -Wnested-externs \ -Wold-style-definition -Woverlength-strings -Wpointer-arith \ - -Wshadow -Wshift-overflow=2 -Wstrict-prototypes -Wstringop-overflow=5 \ + -Wshadow -Wshift-overflow=2 -Wstrict-prototypes -Wstringop-overflow=4 \ + -Wstringop-truncation -Wsuggest-attribute=cold \ -Wsuggest-attribute=const -Wsuggest-attribute=format \ + -Wsuggest-attribute=malloc \ -Wsuggest-attribute=noreturn -Wsuggest-attribute=pure \ -Wtrampolines -Wundef -Wuninitialized -Wunused \ -Wvariadic-macros -Wvla -Wwrite-strings \ @@ -279,7 +300,7 @@ GCC_DEBUG_FLAGS = -DGCC_LINT -g3 -O3 -fno-common \ # "tzsetwall", "offtime", "timelocal", "timegm", "timeoff", # "posix2time", and "time2posix" to be added to the time conversion library. # "tzsetwall" is like "tzset" except that it arranges for local wall clock -# time (rather than the time specified in the TZ environment variable) +# time (rather than the timezone specified in the TZ environment variable) # to be used. # "offtime" is like "gmtime" except that it accepts a second (long) argument # that gives an offset to add to the time_t when converting it. @@ -302,7 +323,7 @@ GCC_DEBUG_FLAGS = -DGCC_LINT -g3 -O3 -fno-common \ # "posix2time_z" and "time2posix_z" are added as well. # The functions ending in "_z" (or "_rz") are like their unsuffixed # (or suffixed-by-"_r") counterparts, except with an extra first -# argument of opaque type timezone_t that specifies the time zone. +# argument of opaque type timezone_t that specifies the timezone. # "tzalloc" allocates a timezone_t value, and "tzfree" frees it. # # If you want to allocate state structures in localtime, add @@ -341,11 +362,14 @@ ZIC= $(zic) $(ZFLAGS) ZFLAGS= -# How to use zic to install tz binary files. +# How to use zic to install TZif files. ZIC_INSTALL= $(ZIC) -d '$(DESTDIR)$(TZDIR)' $(LEAPSECONDS) # The name of a Posix-compliant 'awk' on your system. +# Older 'mawk' versions, such as the 'mawk' in Ubuntu 16.04, might dump core; +# on Ubuntu you can work around this with +# AWK= gawk AWK= awk # The full path name of a Posix-compliant shell, preferably one that supports @@ -394,13 +418,25 @@ SAFE_CHARSET3= 'abcdefghijklmnopqrstuvwxyz{|}~' SAFE_CHARSET= $(SAFE_CHARSET1)$(SAFE_CHARSET2)$(SAFE_CHARSET3) SAFE_CHAR= '[]'$(SAFE_CHARSET)'-]' +# These characters are Latin-1, and so are likely to be displayable +# even in editors with limited character sets. +UNUSUAL_OK_LATIN_1 = «°±»½¾× +# This IPA symbol is represented in Unicode as the composition of +# U+0075 and U+032F, and U+032F is not considered alphabetic by some +# grep implementations that do not grok composition. +UNUSUAL_OK_IPA = u̯ +# Non-ASCII non-letters that OK_CHAR allows, as these characters are +# useful in commentary. +UNUSUAL_OK_CHARSET= $(UNUSUAL_OK_LATIN_1)$(UNUSUAL_OK_IPA) + # OK_CHAR matches any character allowed in the distributed files. -# This is the same as SAFE_CHAR, except that multibyte letters are -# also allowed so that commentary can contain people's names and quote -# non-English sources. For non-letters the sources are limited to -# ASCII renderings for the convenience of maintainers whose text editors -# mishandle UTF-8 by default (e.g., XEmacs 21.4.22). -OK_CHAR= '[][:alpha:]'$(SAFE_CHARSET)'-]' +# This is the same as SAFE_CHAR, except that UNUSUAL_OK_CHARSET and +# multibyte letters are also allowed so that commentary can contain a +# few safe symbols and people's names and can quote non-English sources. +# Other non-letters are limited to ASCII renderings for the +# convenience of maintainers using XEmacs 21.5.34, which by default +# mishandles Unicode characters U+0100 and greater. +OK_CHAR= '[][:alpha:]$(UNUSUAL_OK_CHARSET)'$(SAFE_CHARSET)'-]' # SAFE_LINE matches a line of safe characters. # SAFE_SHARP_LINE is similar, except any OK character can follow '#'; @@ -462,17 +498,22 @@ TDATA= $(YDATA) $(NDATA) $(BACKWARD) ZONETABLES= zone1970.tab zone.tab TABDATA= iso3166.tab $(TZDATA_TEXT) $(ZONETABLES) LEAP_DEPS= leapseconds.awk leap-seconds.list -TZDATA_ZI_DEPS= zishrink.awk version $(TDATA) $(PACKRATDATA) +TZDATA_ZI_DEPS= ziguard.awk zishrink.awk version $(TDATA) $(PACKRATDATA) +DSTDATA_ZI_DEPS= ziguard.awk $(TDATA) $(PACKRATDATA) DATA= $(TDATA_TO_CHECK) backzone iso3166.tab leap-seconds.list \ leapseconds yearistype.sh $(ZONETABLES) -AWK_SCRIPTS= checklinks.awk checktab.awk leapseconds.awk zishrink.awk +AWK_SCRIPTS= checklinks.awk checktab.awk leapseconds.awk \ + ziguard.awk zishrink.awk MISC= $(AWK_SCRIPTS) zoneinfo2tdf.pl TZS_YEAR= 2050 +TZS_CUTOFF_FLAG= -c $(TZS_YEAR) TZS= to$(TZS_YEAR).tzs TZS_NEW= to$(TZS_YEAR)new.tzs TZS_DEPS= $(PRIMARY_YDATA) asctime.c localtime.c \ private.h tzfile.h zdump.c zic.c -ENCHILADA= $(COMMON) $(DOCS) $(SOURCES) $(DATA) $(MISC) $(TZS) tzdata.zi +# EIGHT_YARDS is just a yard short of the whole ENCHILADA. +EIGHT_YARDS = $(COMMON) $(DOCS) $(SOURCES) $(DATA) $(MISC) tzdata.zi +ENCHILADA = $(EIGHT_YARDS) $(TZS) # Consult these files when deciding whether to rebuild the 'version' file. # This list is not the same as the output of 'git ls-files', since @@ -492,6 +533,7 @@ VERSION_DEPS= \ tzfile.5 tzfile.h tzselect.8 tzselect.ksh \ workman.sh yearistype.sh \ zdump.8 zdump.c zic.8 zic.c \ + ziguard.awk zishrink.awk \ zone.tab zone1970.tab zoneinfo2tdf.pl # And for the benefit of csh users on systems that assume the user @@ -499,7 +541,8 @@ VERSION_DEPS= \ SHELL= /bin/sh -all: tzselect yearistype zic zdump libtz.a $(TABDATA) +all: tzselect yearistype zic zdump libtz.a $(TABDATA) \ + vanguard.zi main.zi rearguard.zi ALL: all date $(ENCHILADA) @@ -534,11 +577,22 @@ version: $(VERSION_DEPS) printf '%s\n' "$$V" >$@.out mv $@.out $@ -# This file can be tailored by setting BACKWARD, PACKRATDATA, etc. -tzdata.zi: $(TZDATA_ZI_DEPS) +# These files can be tailored by setting BACKWARD and PACKRATDATA. +vanguard.zi main.zi rearguard.zi: $(DSTDATA_ZI_DEPS) + $(AWK) -v DATAFORM=`expr $@ : '\(.*\).zi'` -f ziguard.awk \ + $(TDATA) $(PACKRATDATA) >$@.out + mv $@.out $@ +# This file has a version comment that attempts to capture any tailoring +# via BACKWARD, DATAFORM, PACKRATDATA, and REDO. +tzdata.zi: $(DATAFORM).zi version zishrink.awk version=`sed 1q version` && \ - LC_ALL=C $(AWK) -v version="$$version" -f zishrink.awk \ - $(TDATA) $(PACKRATDATA) >$@.out + LC_ALL=C $(AWK) \ + -v dataform='$(DATAFORM)' \ + -v deps='$(DSTDATA_ZI_DEPS) zishrink.awk' \ + -v redo='$(REDO)' \ + -v version="$$version" \ + -f zishrink.awk \ + $(DATAFORM).zi >$@.out mv $@.out $@ version.h: version @@ -575,14 +629,16 @@ INSTALLARGS = \ YEARISTYPE='$(YEARISTYPE)' \ ZIC='$(ZIC)' -# 'make install_data' installs one set of tz binary files. -install_data: zic leapseconds yearistype tzdata.zi +INSTALL_DATA_DEPS = zic leapseconds yearistype tzdata.zi + +# 'make install_data' installs one set of TZif files. +install_data: $(INSTALL_DATA_DEPS) $(ZIC_INSTALL) tzdata.zi -posix_only: +posix_only: $(INSTALL_DATA_DEPS) $(MAKE) $(INSTALLARGS) LEAPSECONDS= install_data -right_only: +right_only: $(INSTALL_DATA_DEPS) $(MAKE) $(INSTALLARGS) LEAPSECONDS='-L leapseconds' \ install_data @@ -609,30 +665,44 @@ posix_right: posix_only # This obsolescent rule is present for backwards compatibility with # tz releases 2014g through 2015g. It should go away eventually. -posix_packrat: +posix_packrat: $(INSTALL_DATA_DEPS) $(MAKE) $(INSTALLARGS) PACKRATDATA=backzone posix_only zones: $(REDO) -$(TZS_NEW): tzdata.zi zdump zic - mkdir -p tzs.dir - $(zic) -d tzs.dir tzdata.zi +# dummy.zd is not a real file; it is mentioned here only so that the +# top-level 'make' does not have a syntax error. +ZDS = dummy.zd +# Rule used only by submakes invoked by the $(TZS_NEW) rule. +# It is separate so that GNU 'make -j' can run instances in parallel. +$(ZDS): zdump + ./zdump -i $(TZS_CUTOFF_FLAG) '$(wd)/'$$(expr $@ : '\(.*\).zd') \ + >$@ + +TZS_NEW_DEPS = tzdata.zi zdump zic +$(TZS_NEW): $(TZS_NEW_DEPS) + rm -fr tzs$(TZS_YEAR).dir + mkdir tzs$(TZS_YEAR).dir + $(zic) -d tzs$(TZS_YEAR).dir tzdata.zi $(AWK) '/^L/{print "Link\t" $$2 "\t" $$3}' \ tzdata.zi | LC_ALL=C sort >$@.out wd=`pwd` && \ - zones=`$(AWK) -v wd="$$wd" \ - '/^Z/{print wd "/tzs.dir/" $$2}' tzdata.zi \ - | LC_ALL=C sort` && \ - ./zdump -i -c $(TZS_YEAR) $$zones >>$@.out - sed 's,^TZ=".*tzs\.dir/,TZ=",' $@.out >$@.sed.out - rm -fr tzs.dir $@.out - mv $@.sed.out $@ - -# If $(TZS) does not already exist (e.g., old-format tarballs), create it. -# If it exists but 'make check_tzs' fails, a maintainer should inspect the + x=`$(AWK) '/^Z/{print "tzs$(TZS_YEAR).dir/" $$2 ".zd"}' \ + tzdata.zi \ + | LC_ALL=C sort -t . -k 2,2` && \ + set x $$x && \ + shift && \ + ZDS=$$* && \ + $(MAKE) wd="$$wd" TZS_CUTOFF_FLAG="$(TZS_CUTOFF_FLAG)" \ + ZDS="$$ZDS" $$ZDS && \ + sed 's,^TZ=".*\.dir/,TZ=",' $$ZDS >>$@.out + rm -fr tzs$(TZS_YEAR).dir + mv $@.out $@ + +# If $(TZS) exists but 'make check_tzs' fails, a maintainer should inspect the # failed output and fix the inconsistency, perhaps by running 'make force_tzs'. $(TZS): - $(MAKE) force_tzs + touch $@ force_tzs: $(TZS_NEW) cp $(TZS_NEW) $(TZS) @@ -669,18 +739,23 @@ check_character_set: $(ENCHILADA) sharp='#' && \ ! grep -Env $(SAFE_LINE) $(MANS) date.1 $(MANTXTS) \ $(MISC) $(SOURCES) $(WEB_PAGES) \ - CONTRIBUTING LICENSE Makefile README \ + CONTRIBUTING LICENSE README \ version tzdata.zi && \ + ! grep -Env $(SAFE_LINE)'|^UNUSUAL_OK_'$(OK_CHAR)'*$$' \ + Makefile && \ ! grep -Env $(SAFE_SHARP_LINE) $(TDATA_TO_CHECK) backzone \ leapseconds yearistype.sh zone.tab && \ ! grep -Env $(OK_LINE) $(ENCHILADA); \ } + touch $@ check_white_space: $(ENCHILADA) patfmt=' \t|[\f\r\v]' && pat=`printf "$$patfmt\\n"` && \ - ! grep -En "$$pat" $(ENCHILADA) + ! grep -En "$$pat" \ + $$(ls $(ENCHILADA) | grep -Fvx leap-seconds.list) ! grep -n '[[:space:]]$$' \ $$(ls $(ENCHILADA) | grep -Fvx leap-seconds.list) + touch $@ PRECEDES_FILE_NAME = ^(Zone|Link[[:space:]]+[^[:space:]]+)[[:space:]]+ FILE_NAME_COMPONENT_TOO_LONG = \ @@ -689,6 +764,7 @@ FILE_NAME_COMPONENT_TOO_LONG = \ check_name_lengths: $(TDATA_TO_CHECK) backzone ! grep -En '$(FILE_NAME_COMPONENT_TOO_LONG)' \ $(TDATA_TO_CHECK) backzone + touch $@ CHECK_CC_LIST = { n = split($$1,a,/,/); for (i=2; i<=n; i++) print a[1], a[i]; } @@ -701,46 +777,64 @@ check_sorted: backward backzone iso3166.tab zone.tab zone1970.tab LC_ALL=C sort -c $(AWK) '/^[^#]/ $(CHECK_CC_LIST)' zone1970.tab | \ LC_ALL=C sort -cu + touch $@ -check_links: checklinks.awk $(TDATA_TO_CHECK) +check_links: checklinks.awk $(TDATA_TO_CHECK) tzdata.zi $(AWK) -f checklinks.awk $(TDATA_TO_CHECK) $(AWK) -f checklinks.awk tzdata.zi + touch $@ check_tables: checktab.awk $(PRIMARY_YDATA) $(ZONETABLES) for tab in $(ZONETABLES); do \ $(AWK) -f checktab.awk -v zone_table=$$tab $(PRIMARY_YDATA) \ || exit; \ done + touch $@ check_tzs: $(TZS) $(TZS_NEW) - diff -u $(TZS) $(TZS_NEW) + if test -s $(TZS); then \ + diff -u $(TZS) $(TZS_NEW); \ + else \ + cp $(TZS_NEW) $(TZS); \ + fi + touch $@ # This checks only the HTML 4.01 strict page. # To check the the other pages, use . check_web: tz-how-to.html $(VALIDATE_ENV) $(VALIDATE) $(VALIDATE_FLAGS) tz-how-to.html + touch $@ -# Check that tzdata.zi generates the same binary data that its sources do. -check_zishrink: tzdata.zi zic leapseconds $(PACKRATDATA) $(TDATA) - for type in posix right; do \ - mkdir -p time_t.dir/$$type time_t.dir/$$type-shrunk && \ - case $$type in \ - right) leap='-L leapseconds';; \ - *) leap=;; \ - esac && \ - $(ZIC) $$leap -d time_t.dir/$$type $(TDATA) && \ - $(AWK) '/^Rule/' $(TDATA) | \ - $(ZIC) $$leap -d time_t.dir/$$type - $(PACKRATDATA) && \ - $(ZIC) $$leap -d time_t.dir/$$type-shrunk tzdata.zi && \ - diff -r time_t.dir/$$type time_t.dir/$$type-shrunk || exit; \ - done - rm -fr time_t.dir +# Check that zishrink.awk does not alter the data, and that ziguard.awk +# preserves main-format data. +check_zishrink: check_zishrink_posix check_zishrink_right +check_zishrink_posix check_zishrink_right: \ + zic leapseconds $(PACKRATDATA) $(TDATA) $(DATAFORM).zi tzdata.zi + rm -fr $@.dir $@-t.dir $@-shrunk.dir + mkdir $@.dir $@-t.dir $@-shrunk.dir + case $@ in \ + *_right) leap='-L leapseconds';; \ + *) leap=;; \ + esac && \ + $(ZIC) $$leap -d $@.dir $(DATAFORM).zi && \ + $(ZIC) $$leap -d $@-shrunk.dir tzdata.zi && \ + case $(DATAFORM) in \ + main) \ + $(ZIC) $$leap -d $@-t.dir $(TDATA) && \ + $(AWK) '/^Rule/' $(TDATA) | \ + $(ZIC) $$leap -d $@-t.dir - $(PACKRATDATA) && \ + diff -r $@.dir $@-t.dir;; \ + esac + diff -r $@.dir $@-shrunk.dir + rm -fr $@.dir $@-t.dir $@-shrunk.dir + touch $@ clean_misc: - rm -f core *.o *.out \ + rm -f *.o *.out $(TIME_T_ALTERNATIVES) \ + check_* core typecheck_* \ date tzselect version.h zdump zic yearistype libtz.a clean: clean_misc - rm -fr *.dir tzdata.zi tzdb-*/ $(TZS_NEW) + rm -fr *.dir *.zi tzdb-*/ $(TZS_NEW) maintainer-clean: clean @echo 'This command is intended for maintainers to use; it' @@ -767,17 +861,17 @@ $(MANTXTS): workman.sh LC_ALL=C sh workman.sh `expr $@ : '\(.*\)\.txt$$'` >$@.out mv $@.out $@ -# Set the time stamps to those of the git repository, if available, +# Set the timestamps to those of the git repository, if available, # and if the files have not changed since then. # This uses GNU 'touch' syntax 'touch -d@N FILE', # where N is the number of seconds since 1970. # If git or GNU 'touch' is absent, don't bother to sync with git timestamps. # Also, set the timestamp of each prebuilt file like 'leapseconds' # to be the maximum of the files it depends on. -set-timestamps.out: $(ENCHILADA) +set-timestamps.out: $(EIGHT_YARDS) rm -f $@ if (type git) >/dev/null 2>&1 && \ - files=`git ls-files $(ENCHILADA)` && \ + files=`git ls-files $(EIGHT_YARDS)` && \ touch -md @1 test.out; then \ rm -f test.out && \ for file in $$files; do \ @@ -795,73 +889,101 @@ set-timestamps.out: $(ENCHILADA) exit; \ done touch -cmr `ls -t $(TZDATA_ZI_DEPS) | sed 1q` tzdata.zi - touch -cmr `ls -t $(TZS_DEPS) | sed 1q` $(TZS) touch -cmr `ls -t $(VERSION_DEPS) | sed 1q` version touch $@ +set-tzs-timestamp.out: $(TZS) + touch -cmr `ls -t $(TZS_DEPS) | sed 1q` $(TZS) + touch $@ # The zics below ensure that each data file can stand on its own. # We also do an all-files run to catch links to links. -check_public: - $(MAKE) maintainer-clean - $(MAKE) CFLAGS='$(GCC_DEBUG_FLAGS)' ALL - mkdir -p public.dir - for i in $(TDATA_TO_CHECK) tzdata.zi; do \ - $(zic) -v -d public.dir $$i 2>&1 || exit; \ +check_public: $(VERSION_DEPS) + rm -fr public.dir + mkdir public.dir + ln $(VERSION_DEPS) public.dir + cd public.dir && $(MAKE) CFLAGS='$(GCC_DEBUG_FLAGS)' ALL + for i in $(TDATA_TO_CHECK) public.dir/tzdata.zi; do \ + public.dir/zic -v -d public.dir/zoneinfo $$i 2>&1 || exit; \ done - $(zic) -v -d public.dir $(TDATA_TO_CHECK) + public.dir/zic -v -d public.dir/zoneinfo-all $(TDATA_TO_CHECK) rm -fr public.dir + touch $@ # Check that the code works under various alternative # implementations of time_t. -check_time_t_alternatives: - if diff -q Makefile Makefile 2>/dev/null; then \ - quiet_option='-q'; \ - else \ - quiet_option=''; \ - fi && \ +check_time_t_alternatives: $(TIME_T_ALTERNATIVES) +$(TIME_T_ALTERNATIVES_TAIL): $(TIME_T_ALTERNATIVES_HEAD) +$(TIME_T_ALTERNATIVES): $(VERSION_DEPS) + rm -fr $@.dir + mkdir $@.dir + ln $(VERSION_DEPS) $@.dir + case $@ in \ + int32_t) range=-2147483648,2147483648;; \ + u*) range=0,4294967296;; \ + *) range=-4294967296,4294967296;; \ + esac && \ wd=`pwd` && \ zones=`$(AWK) '/^[^#]/ { print $$3 }' time_t.dir/int64_t.out && \ - time_t.dir/$$type/usr/bin/zdump -V -t $$range $$zones \ - >time_t.dir/$$type.out && \ - diff -u time_t.dir/int64_t.out time_t.dir/$$type.out \ - || exit; \ - done - rm -fr time_t.dir + D=$$wd/$@.dir \ + TZS_YEAR="$$range" TZS_CUTOFF_FLAG="-t $$range" \ + install $$range_target) && \ + test $@ = $(TIME_T_ALTERNATIVES_HEAD) || { \ + (cd $(TIME_T_ALTERNATIVES_HEAD).dir && \ + $(MAKE) TOPDIR="$$wd/$@.dir" \ + TZS_YEAR="$$range" TZS_CUTOFF_FLAG="-t $$range" \ + D=$$wd/$@.dir \ + to$$range.tzs) && \ + diff -u $(TIME_T_ALTERNATIVES_HEAD).dir/to$$range.tzs \ + $@.dir/to$$range.tzs && \ + if diff -q Makefile Makefile 2>/dev/null; then \ + quiet_option='-q'; \ + else \ + quiet_option=''; \ + fi && \ + diff $$quiet_option -r $(TIME_T_ALTERNATIVES_HEAD).dir/etc \ + $@.dir/etc && \ + diff $$quiet_option -r \ + $(TIME_T_ALTERNATIVES_HEAD).dir/usr/share \ + $@.dir/usr/share; \ + } + touch $@ -tarballs traditional_tarballs signatures traditional_signatures: version +TRADITIONAL_ASC = \ + tzcode$(VERSION).tar.gz.asc \ + tzdata$(VERSION).tar.gz.asc +REARGUARD_ASC = \ + tzdata$(VERSION)-rearguard.tar.gz.asc +ALL_ASC = $(TRADITIONAL_ASC) $(REARGUARD_ASC) \ + tzdb-$(VERSION).tar.lz.asc + +tarballs rearguard_tarballs traditional_tarballs \ +signatures rearguard_signatures traditional_signatures: \ + version set-timestamps.out rearguard.zi VERSION=`cat version` && \ $(MAKE) VERSION="$$VERSION" $@_version -tarballs_version: traditional_tarballs_version tzdb-$(VERSION).tar.lz +# These *_version rules are intended for use if VERSION is set by some +# other means. Ordinarily these rules are used only by the above +# non-_version rules, which set VERSION on the 'make' command line. +tarballs_version: traditional_tarballs_version rearguard_tarballs_version \ + tzdb-$(VERSION).tar.lz +rearguard_tarballs_version: \ + tzdata$(VERSION)-rearguard.tar.gz traditional_tarballs_version: \ tzcode$(VERSION).tar.gz tzdata$(VERSION).tar.gz -signatures_version: traditional_signatures_version tzdb-$(VERSION).tar.lz.asc -traditional_signatures_version: \ - tzcode$(VERSION).tar.gz.asc tzdata$(VERSION).tar.gz.asc \ +signatures_version: $(ALL_ASC) +rearguard_signatures_version: $(REARGUARD_ASC) +traditional_signatures_version: $(TRADITIONAL_ASC) tzcode$(VERSION).tar.gz: set-timestamps.out LC_ALL=C && export LC_ALL && \ @@ -876,7 +998,27 @@ tzdata$(VERSION).tar.gz: set-timestamps.out gzip $(GZIPFLAGS) >$@.out mv $@.out $@ -tzdb-$(VERSION).tar.lz: set-timestamps.out +tzdata$(VERSION)-rearguard.tar.gz: rearguard.zi set-timestamps.out + rm -fr tzdata$(VERSION)-rearguard.dir + mkdir tzdata$(VERSION)-rearguard.dir + ln $(COMMON) $(DATA) $(MISC) tzdata$(VERSION)-rearguard.dir + cd tzdata$(VERSION)-rearguard.dir && \ + rm -f $(TDATA) $(PACKRATDATA) version + for f in $(TDATA) $(PACKRATDATA); do \ + rearf=tzdata$(VERSION)-rearguard.dir/$$f; \ + $(AWK) -v DATAFORM=rearguard -f ziguard.awk $$f >$$rearf && \ + touch -cmr `ls -t ziguard.awk $$f` $$rearf || exit; \ + done + sed '1s/$$/-rearguard/' \ + tzdata$(VERSION)-rearguard.dir/version + touch -cmr version tzdata$(VERSION)-rearguard.dir/version + LC_ALL=C && export LC_ALL && \ + (cd tzdata$(VERSION)-rearguard.dir && \ + tar $(TARFLAGS) -cf - $(COMMON) $(DATA) $(MISC) | \ + gzip $(GZIPFLAGS)) >$@.out + mv $@.out $@ + +tzdb-$(VERSION).tar.lz: set-timestamps.out set-tzs-timestamp.out rm -fr tzdb-$(VERSION) mkdir tzdb-$(VERSION) ln $(ENCHILADA) tzdb-$(VERSION) @@ -886,22 +1028,30 @@ tzdb-$(VERSION).tar.lz: set-timestamps.out mv $@.out $@ tzcode$(VERSION).tar.gz.asc: tzcode$(VERSION).tar.gz - gpg --armor --detach-sign $? - tzdata$(VERSION).tar.gz.asc: tzdata$(VERSION).tar.gz - gpg --armor --detach-sign $? - +tzdata$(VERSION)-rearguard.tar.gz.asc: tzdata$(VERSION)-rearguard.tar.gz tzdb-$(VERSION).tar.lz.asc: tzdb-$(VERSION).tar.lz - gpg --armor --detach-sign $? - -typecheck: - $(MAKE) clean - for i in "long long" unsigned; \ - do \ - $(MAKE) CFLAGS="-DTYPECHECK -D__time_t_defined -D_TIME_T \"-Dtime_t=$$i\"" ; \ - ./zdump -v Europe/Rome ; \ - $(MAKE) clean ; \ - done +$(ALL_ASC): + gpg2 --armor --detach-sign $? + +TYPECHECK_CFLAGS = $(CFLAGS) -DTYPECHECK -D__time_t_defined -D_TIME_T +typecheck: typecheck_long_long typecheck_unsigned +typecheck_long_long typecheck_unsigned: $(VERSION_DEPS) + rm -fr $@.dir + mkdir $@.dir + ln $(VERSION_DEPS) $@.dir + cd $@.dir && \ + case $@ in \ + *_long_long) i="long long";; \ + *_unsigned ) i="unsigned" ;; \ + esac && \ + typecheck_cflags='' && \ + $(MAKE) \ + CFLAGS="$(TYPECHECK_CFLAGS) \"-Dtime_t=$$i\"" \ + TOPDIR="`pwd`" \ + install + $@.dir/zdump -i -c 1970,1971 Europe/Rome + touch $@ zonenames: tzdata.zi @$(AWK) '/^Z/ { print $$2 } /^L/ { print $$3 }' tzdata.zi @@ -917,13 +1067,17 @@ zic.o: private.h tzfile.h version.h .KEEP_STATE: .PHONY: ALL INSTALL all -.PHONY: check check_character_set check_links -.PHONY: check_public check_sorted check_tables -.PHONY: check_time_t_alternatives check_tzs check_web check_white_space +.PHONY: check check_time_t_alternatives .PHONY: check_zishrink -.PHONY: clean clean_misc force_tzs +.PHONY: clean clean_misc dummy.zd force_tzs .PHONY: install install_data maintainer-clean names -.PHONY: posix_only posix_packrat posix_right -.PHONY: public right_only right_posix signatures signatures_version -.PHONY: tarballs tarballs_version typecheck +.PHONY: posix_only posix_packrat posix_right public +.PHONY: rearguard_signatures rearguard_signatures_version +.PHONY: rearguard_tarballs rearguard_tarballs_version +.PHONY: right_only right_posix signatures signatures_version +.PHONY: tarballs tarballs_version +.PHONY: traditional_signatures traditional_signatures_version +.PHONY: traditional_tarballs traditional_tarballs_version +.PHONY: typecheck .PHONY: zonenames zones +.PHONY: $(ZDS) diff --git a/contrib/tzdata/NEWS b/contrib/tzdata/NEWS index 2bd0aa8414..d4cb723657 100644 --- a/contrib/tzdata/NEWS +++ b/contrib/tzdata/NEWS @@ -1,9 +1,376 @@ News for the tz database +Release 2018g - 2018-10-26 22:22:45 -0700 + + Briefly: + Morocco switches to permanent +01 on 2018-10-27. + + Changes to future timestamps + + Morocco switches from +00/+01 to permanent +01 effective 2018-10-27, + so its clocks will not fall back on 2018-10-28 as previously scheduled. + (Thanks to Mohamed Essedik Najd and Brian Inglis.) + + Changes to code + + When generating TZif files with leap seconds, zic no longer uses a + format that trips up older 32-bit clients, fixing a bug introduced + in 2018f. (Reported by Daniel Fischer.) Also, the zic workaround + for QTBUG-53071 now also works for TZif files with leap seconds. + + The translator to rearguard format now rewrites the line + "Rule Japan 1948 1951 - Sep Sat>=8 25:00 0 S" to + "Rule Japan 1948 1951 - Sep Sun>=9 1:00 0 S". + This caters to zic before 2007 and to Oracle TZUpdater 2.2.0 + and earlier. (Reported by Christos Zoulas.) + + Changes to past time zone abbreviations + + Change HDT to HWT/HPT for WWII-era abbreviations in Hawaii. + This reverts to 2011h, as the abbreviation change in 2011i was + likely inadvertent. + + Changes to documentation + + tzfile.5 has new sections on interoperability issues. + + +Release 2018f - 2018-10-18 00:14:18 -0700 + + Briefly: + Volgograd moves from +03 to +04 on 2018-10-28. + Fiji ends DST 2019-01-13, not 2019-01-20. + Most of Chile changes DST dates, effective 2019-04-06. + + Changes to future timestamps + + Volgograd moves from +03 to +04 on 2018-10-28 at 02:00. + (Thanks to Alexander Fetisov and Stepan Golosunov.) + + Fiji ends DST 2019-01-13 instead of the 2019-01-20 previously + predicted. (Thanks to Raymond Kumar.) Adjust future predictions + accordingly. + + Most of Chile will end DST on the first Saturday in April at 24:00 mainland + time, and resume DST on the first Saturday in September at 24:00 mainland + time. The changes are effective from 2019-04-06, and do not affect the + Magallanes region modeled by America/Punta_Arenas. (Thanks to Juan Correa + and Tim Parenti.) Adjust future predictions accordingly. + + Changes to past timestamps + + The 2018-05-05 North Korea 30-minute time zone change took place + at 23:30 the previous day, not at 00:00 that day. + + China's 1988 spring-forward transition was on April 17, not + April 10. Its DST transitions in 1986/91 were at 02:00, not 00:00. + (Thanks to P Chan.) + + Fix several issues for Macau before 1992. Macau's pre-1904 LMT + was off by 10 s. Macau switched to +08 in 1904 not 1912, and + temporarily switched to +09/+10 during World War II. Macau + observed DST in 1942/79, not 1961/80, and there were several + errors for transition times and dates. (Thanks to P Chan.) + + The 1948-1951 fallback transitions in Japan were at 25:00 on + September's second Saturday, not at 24:00. (Thanks to Phake Nick.) + zic turns this into 01:00 on the day after September's second + Saturday, which is the best that POSIX or C platforms can do. + + Incorporate 1940-1949 Asia/Shanghai DST transitions from a 2014 + paper by Li Yu, replacing more-questionable data from Shanks. + + Changes to time zone abbreviations + + Use "PST" and "PDT" for Philippine time. (Thanks to Paul Goyette.) + + Changes to code + + zic now always generates TZif files where time type 0 is used for + timestamps before the first transition. This simplifies the + reading of TZif files and should not affect behavior of existing + TZif readers because the same set of time types is used; only + their internal indexes may have changed. This affects only the + legacy zones EST5EDT, CST6CDT, MST7MDT, PST8PDT, CET, MET, and + EET, which previously used nonzero types for these timestamps. + + Because of the type 0 change, zic no longer outputs a dummy + transition at time -2**59 (before the Big Bang), as clients should + no longer need this to handle historical timestamps correctly. + This reverts a change introduced in 2013d and shrinks most TZif + files by a few bytes. + + zic now supports negative time-of-day in Rule and Leap lines, e.g., + "Rule X min max - Apr lastSun -6:00 1:00 -" means the transition + occurs at 18:00 on the Saturday before the last Sunday in April. + This behavior was documented in 2018a but the code did not + entirely match the documentation. + + localtime.c no longer requires at least one time type in TZif + files that lack transitions or have a POSIX-style TZ string. This + future-proofs the code against possible future extensions to the + format that would allow TZif files with POSIX-style TZ strings and + without transitions or time types. + + A read-access subscript error in localtime.c has been fixed. + It could occur only in TZif files with timecnt == 0, something that + does not happen in practice now but could happen in future versions. + + localtime.c no longer ignores TZif POSIX-style TZ strings that + specify only standard time. Instead, these TZ strings now + override the default time type for timestamps after the last + transition (or for all time stamps if there are no transitions), + just as DST strings specifying DST have always done. + + leapseconds.awk now outputs "#updated" and "#expires" comments, + and supports leap seconds at the ends of months other than June + and December. (Inspired by suggestions from Chris Woodbury.) + + Changes to documentation + + New restrictions: A Rule name must start with a character that + is neither an ASCII digit nor "-" nor "+", and an unquoted name + should not use characters in the set "!$%&'()*,/:;<=>?@[\]^`{|}~". + The latter restriction makes room for future extensions (a + possibility noted by Tom Lane). + + tzfile.5 now documents what time types apply before the first and + after the last transition, if any. + + Documentation now uses the spelling "timezone" for a TZ setting + that determines timestamp history, and "time zone" for a + geographic region currently sharing the same standard time. + + The name "TZif" is now used for the tz binary data format. + + tz-link.htm now mentions the A0 TimeZone Migration utilities. + (Thanks to Aldrin Martoq for the link.) + + Changes to build procedure + + New 'make' target 'rearguard_tarballs' to build the rearguard + tarball only. This is a convenience on platforms that lack lzip + if you want to build the rearguard tarball. (Problem reported by + Deborah Goldsmith.) + + tzdata.zi is now more stable from release to release. (Problem + noted by Tom Lane.) It is also a bit shorter. + + tzdata.zi now can contain comment lines documenting configuration + information, such as which data format was selected, which input + files were used, and how leap seconds are treated. (Problems + noted by Lester Caine and Brian Inglis.) If the Makefile defaults + are used these comment lines are absent, for backward + compatibility. A redistributor intending to alter its copy of the + files should also append "-LABEL" to the 'version' file's first + line, where "LABEL" identifies the redistributor's change. + + +Release 2018e - 2018-05-01 23:42:51 -0700 + + Briefly: + + North Korea switches back to +09 on 2018-05-05. + The main format uses negative DST again, for Ireland etc. + 'make tarballs' now also builds a rearguard tarball. + New 's' and 'd' suffixes in SAVE columns of Rule and Zone lines. + + Changes to past and future timestamps + + North Korea switches back from +0830 to +09 on 2018-05-05. + (Thanks to Kang Seonghoon, Arthur David Olson, Seo Sanghyeon, + and Tim Parenti.) + + Bring back the negative-DST changes of 2018a, except be more + compatible with data parsers that do not support negative DST. + Also, this now affects historical timestamps in Namibia and the + former Czechoslovakia, not just Ireland. The main format now uses + negative DST to model timestamps in Europe/Dublin (from 1971 on), + Europe/Prague (1946/7), and Africa/Windhoek (1994/2017). This + does not affect UT offsets, only time zone abbreviations and the + tm_isdst flag. Also, this does not affect rearguard or vanguard + formats; effectively the main format now uses vanguard instead of + rearguard format. Data parsers that do not support negative DST + can still use data from the rearguard tarball described below. + + Changes to build procedure + + The command 'make tarballs' now also builds the tarball + tzdataVERSION-rearguard.tar.gz, which is like tzdataVERSION.tar.gz + except that it uses rearguard format intended for trailing-edge + data parsers. + + Changes to data format and to code + + The SAVE column of Rule and Zone lines can now have an 's' or 'd' + suffix, which specifies whether the adjusted time is standard time + or daylight saving time. If no suffix is given, daylight saving + time is used if and only if the SAVE column is nonzero; this is + the longstanding behavior. Although this new feature is not used + in tzdata, it could be used to specify the legal time in Namibia + 1994-2017, as opposed to the popular time (see below). + + Changes to past timestamps + + From 1994 through 2017 Namibia observed DST in winter, not summer. + That is, it used negative DST, as Ireland still does. This change + does not affect UTC offsets; it affects only the tm_isdst flag and + the abbreviation used during summer, which is now CAT, not WAST. + Although (as noted by Michael Deckers) summer and winter time were + both simply called "standard time" in Namibian law, in common + practice winter time was considered to be DST (as noted by Stephen + Colebourne). The full effect of this change is only in vanguard + and main format; in rearguard format, the tm_isdst flag is still + zero in winter and nonzero in summer. + + In 1946/7 Czechoslovakia also observed negative DST in winter. + The full effect of this change is only in vanguard and main + formats; in rearguard format, it is modeled as plain GMT without + daylight saving. Also, the dates of some 1944/5 DST transitions + in Czechoslovakia have been changed. + + +Release 2018d - 2018-03-22 07:05:46 -0700 + + Briefly: + + Palestine starts DST a week earlier in 2018. + Add support for vanguard and rearguard data consumers. + Add subsecond precision to source data format, though not to data. + + Changes to future timestamps + + In 2018, Palestine starts DST on March 24, not March 31. + Adjust future predictions accordingly. (Thanks to Sharef Mustafa.) + + Changes to past and future timestamps + + Casey Station in Antarctica changed from +11 to +08 on 2018-03-11 + at 04:00. (Thanks to Steffen Thorsen.) + + Changes to past timestamps + + Historical transitions for Uruguay, represented by + America/Montevideo, have been updated per official legal documents, + replacing previous data mainly originating from the inventions of + Shanks & Pottenger. This has resulted in adjustments ranging from + 30 to 90 minutes in either direction over at least two dozen + distinct periods ranging from one day to several years in length. + A mere handful of pre-1991 transitions are unaffected; data since + then has come from more reliable contemporaneous reporting. These + changes affect various timestamps in 1920-1923, 1936, 1939, + 1942-1943, 1959, 1966-1970, 1972, 1974-1980, and 1988-1990. + Additionally, Uruguay's pre-standard-time UT offset has been + adjusted westward by 7 seconds, from UT-03:44:44 to UT-03:44:51, to + match the location of the Observatory of the National Meteorological + Institute in Montevideo. + (Thanks to Jeremie Bonjour, Tim Parenti, and Michael Deckers.) + + Enderbury and Kiritimati skipped New Year's Eve 1994, not + New Year's Day 1995. (Thanks to Kerry Shetline.) + + Fix the 1912-01-01 transition for Portugal and its colonies. + This transition was at 00:00 according to the new UT offset, not + according to the old one. Also assume that Cape Verde switched on + the same date as the rest, not in 1907. This affects + Africa/Bissau, Africa/Sao_Tome, Asia/Macau, Atlantic/Azores, + Atlantic/Cape_Verde, Atlantic/Madeira, and Europe/Lisbon. + (Thanks to Michael Deckers.) + + Fix an off-by-1 error for pre-1913 timestamps in Jamaica and in + Turks & Caicos. + + Changes to past time zone abbreviations + + MMT took effect in Uruguay from 1908-06-10, not 1898-06-28. There + is no clock change associated with the transition. + + Changes to build procedure + + The new DATAFORM macro in the Makefile lets the installer choose + among three source data formats. The idea is to lessen downstream + disruption when data formats are improved. + + * DATAFORM=vanguard installs from the latest, bleeding-edge + format. DATAFORM=main (the default) installs from the format + used in the 'africa' etc. files. DATAFORM=rearguard installs + from a trailing-edge format. Eventually, elements of today's + vanguard format should move to the main format, and similarly + the main format's features should eventually move to the + rearguard format. + + * In the current version, the main and rearguard formats are + identical and match that of 2018c, so this change does not + affect default behavior. The vanguard format currently contains + one feature not in the main format: negative SAVE values. This + improves support for Ireland, which uses Irish Standard Time + (IST, UTC+01) in summer and GMT (UTC) in winter. tzcode has + supported negative SAVE values for decades, and this feature + should move to the main format soon. However, it will not move + to the rearguard format for quite some time because some + downstream parsers do not support it. + + * The build procedure constructs three files vanguard.zi, main.zi, + and rearguard.zi, one for each format. The files represent the + same data as closely as the formats allow. These three files + are intended for downstream data consumers and are not + installed. Zoneinfo parsers that do not support negative SAVE values + should start using rearguard.zi, so that they will be unaffected + when the negative-DST feature moves from vanguard to main. + Bleeding-edge Zoneinfo parsers that support the new features + already can use vanguard.zi; in this respect, current tzcode is + bleeding-edge. + + The Makefile should now be safe for parallelized builds, and 'make + -j to2050new.tzs' is now much faster on a multiprocessor host + with GNU Make. + + When built with -DSUPPRESS_TZDIR, the tzcode library no longer + prepends TZDIR/ to file names that do not begin with '/'. This is + not recommended for general use, due to its security implications. + (From a suggestion by Manuela Friedrich.) + + Changes to code + + zic now accepts subsecond precision in expressions like + 00:19:32.13, which is approximately the legal time of the + Netherlands from 1835 to 1937. However, because it is + questionable whether the few recorded uses of non-integer offsets + had subsecond precision in practice, there are no plans for tzdata + to use this feature. (Thanks to Steve Allen for pointing out + the limitations of historical data in this area.) + + The code is a bit more portable to MS-Windows. Installers can + compile with -DRESERVE_STD_EXT_IDS on MS-Windows platforms that + reserve identifiers like 'localtime'. (Thanks to Manuela + Friedrich). + + Changes to documentation and commentary + + theory.html now outlines tzdb's extensions to POSIX's model for + civil time, and has a section "POSIX features no longer needed" + that lists POSIX API components that are now vestigial. + (From suggestions by Steve Summit.) It also better distinguishes + time zones from tz regions. (From a suggestion by Guy Harris.) + + Commentary is now more consistent about using the phrase "daylight + saving time", to match the C name tm_isdst. Daylight saving time + need not occur in summer, and need not have a positive offset from + standard time. + + Commentary about historical transitions in Uruguay has been expanded + with links to many relevant legal documents. + (Thanks to Tim Parenti.) + + Commentary now uses some non-ASCII characters with Unicode value + less than U+0100, as they can be useful and should work even with + older editors such as XEmacs. + + Release 2018c - 2018-01-22 23:00:44 -0800 Briefly: - Revert Irish changes that relied on negative DST offsets. + Revert Irish changes that relied on negative SAVE values. Changes to tm_isdst @@ -14,8 +381,8 @@ Release 2018c - 2018-01-22 23:00:44 -0800 struct tm type. This reversion is intended to be a temporary workaround for problems discovered with downstream uses of releases 2018a and 2018b, which implemented Irish time by using - negative DST offsets in the Eire rules of the 'europe' file. - Although negative DST offsets have been part of tzcode for many + negative SAVE values in the Eire rules of the 'europe' file. + Although negative SAVE values have been part of tzcode for many years and are supported by many platforms, they were not documented before 2018a and ICU and OpenJDK do not currently support them. A mechanism to export data to platforms lacking @@ -23,7 +390,7 @@ Release 2018c - 2018-01-22 23:00:44 -0800 change is reapplied. (Problems reported by Deborah Goldsmith and Stephen Colebourne.) - Changes to past time stamps + Changes to past timestamps Japanese DST transitions (1948-1951) were Sundays at 00:00, not Saturdays or Sundays at 02:00. (Thanks to Takayuki Nikai.) @@ -55,18 +422,18 @@ Release 2018a - 2018-01-12 22:29:21 -0800 Use Debian-style installation locations, instead of 4.3BSD-style. New zic option -t. - Changes to past and future time stamps + Changes to past and future timestamps São Tomé and Príncipe switched from +00 to +01 on 2018-01-01 at 01:00. (Thanks to Steffen Thorsen and Michael Deckers.) - Changes to future time stamps + Changes to future timestamps Starting in 2018 southern Brazil will begin DST on November's first Sunday instead of October's third Sunday. (Thanks to Steffen Thorsen.) - Changes to past time stamps + Changes to past timestamps A discrepancy of 4 s in timestamps before 1931 in South Sudan has been corrected. The 'backzone' and 'zone.tab' files did not agree @@ -154,7 +521,7 @@ Release 2017c - 2017-10-20 14:49:34 -0700 A new file tzdata.zi now holds a small text copy of all data. The zic input format has been regularized slightly. - Changes to future time stamps + Changes to future timestamps Northern Cyprus has decided to resume EU rules starting 2017-10-29, thus reinstituting winter time. @@ -180,7 +547,7 @@ Release 2017c - 2017-10-20 14:49:34 -0700 2018-03-11 at 03:00. This affects UT offsets starting 2018-11-04 at 02:00. (Thanks to Steffen Thorsen.) - Changes to past time stamps + Changes to past timestamps Namibia switched from +02 to +01 on 1994-03-21, not 1994-04-03. (Thanks to Arthur David Olson.) @@ -310,11 +677,11 @@ Release 2017b - 2017-03-17 07:30:38 -0700 Briefly: Haiti has resumed DST. - Changes to past and future time stamps + Changes to past and future timestamps Haiti resumed observance of DST in 2017. (Thanks to Steffen Thorsen.) - Changes to past time stamps + Changes to past timestamps Liberia changed from -004430 to +00 on 1972-01-07, not 1972-05-01. @@ -326,7 +693,7 @@ Release 2017b - 2017-03-17 07:30:38 -0700 The reference localtime implementation now falls back on the current US daylight-saving transition rules rather than the 1987-2006 rules. This fallback occurs only when (1) the TZ - environment variable's value has a name like "AST4ADT" that asks + environment variable has a value like "AST4ADT" that asks for daylight saving time but does not specify the rules, (2) there is no file by that name, and (3) the TZDEFRULES file cannot be loaded. (Thanks to Tom Lane.) @@ -337,7 +704,7 @@ Release 2017a - 2017-02-28 00:05:36 -0800 Briefly: Southern Chile moves from -04/-03 to -03, and Mongolia discontinues DST. - Changes to future time stamps + Changes to future timestamps Mongolia no longer observes DST. (Thanks to Ganbold Tsagaankhuu.) @@ -348,12 +715,12 @@ Release 2017a - 2017-02-28 00:05:36 -0800 assume it's permanent. (Thanks to Juan Correa and Deborah Goldsmith.) This also affects Antarctica/Palmer. - Changes to past time stamps + Changes to past timestamps - Fix many entries for historical time stamps for Europe/Madrid + Fix many entries for historical timestamps for Europe/Madrid before 1979, to agree with tables compiled by Pere Planesas of the National Astronomical Observatory of Spain. As a side effect, - this changes some time stamps for Africa/Ceuta before 1929, which + this changes some timestamps for Africa/Ceuta before 1929, which are probably guesswork anyway. (Thanks to Steve Allen and Pierpaolo Bernardi for the heads-ups, and to Michael Deckers for correcting the 1901 transition.) @@ -444,13 +811,13 @@ Release 2016j - 2016-11-22 23:17:13 -0800 Briefly: Saratov, Russia moves from +03 to +04 on 2016-12-04. - Changes to future time stamps + Changes to future timestamps Saratov, Russia switches from +03 to +04 on 2016-12-04 at 02:00. This hives off a new zone Europe/Saratov from Europe/Volgograd. (Thanks to Yuri Konotopov and Stepan Golosunov.) - Changes to past time stamps + Changes to past timestamps The new zone Asia/Atyrau for Atyraū Region, Kazakhstan, is like Asia/Aqtau except it switched from +05/+06 to +04/+05 in spring @@ -486,7 +853,7 @@ Release 2016i - 2016-11-01 23:19:52 -0700 Briefly: Cyprus split into two time zones on 2016-10-30, and Tonga reintroduces DST on 2016-11-06. - Changes to future time stamps + Changes to future timestamps Pacific/Tongatapu begins DST on 2016-11-06 at 02:00, ending on 2017-01-15 at 03:00. Assume future observances in Tonga will be @@ -494,7 +861,7 @@ Release 2016i - 2016-11-01 23:19:52 -0700 January, like Fiji. (Thanks to Pulu ʻAnau.) Switch to numeric time zone abbreviations for this zone. - Changes to past and future time stamps + Changes to past and future timestamps Northern Cyprus is now +03 year round, causing a split in Cyprus time zones starting 2016-10-30 at 04:00. This creates a zone @@ -503,9 +870,9 @@ Release 2016i - 2016-11-01 23:19:52 -0700 Antarctica/Casey switched from +08 to +11 on 2016-10-22. (Thanks to Steffen Thorsen.) - Changes to past time stamps + Changes to past timestamps - Several corrections were made for pre-1975 time stamps in Italy. + Several corrections were made for pre-1975 timestamps in Italy. These affect Europe/Malta, Europe/Rome, Europe/San_Marino, and Europe/Vatican. @@ -543,7 +910,7 @@ Release 2016i - 2016-11-01 23:19:52 -0700 Release 2016h - 2016-10-19 23:17:57 -0700 - Changes to future time stamps + Changes to future timestamps Asia/Gaza and Asia/Hebron end DST on 2016-10-29 at 01:00, not 2016-10-21 at 00:00. (Thanks to Sharef Mustafa.) Predict that @@ -551,7 +918,7 @@ Release 2016h - 2016-10-19 23:17:57 -0700 at 01:00, which is consistent with predicted spring transitions on the last Saturday of March. (Thanks to Tim Parenti.) - Changes to past time stamps + Changes to past timestamps In Turkey, transitions in 1986-1990 were at 01:00 standard time not at 02:00, and the spring 1994 transition was on March 20, not @@ -600,7 +967,7 @@ Release 2016h - 2016-10-19 23:17:57 -0700 Release 2016g - 2016-09-13 08:56:38 -0700 - Changes to future time stamps + Changes to future timestamps Turkey switched from EET/EEST (+02/+03) to permanent +03, effective 2016-09-07. (Thanks to Burak AYDIN.) Use "+03" rather @@ -609,7 +976,7 @@ Release 2016g - 2016-09-13 08:56:38 -0700 New leap second 2016-12-31 23:59:60 UTC as per IERS Bulletin C 52. (Thanks to Tim Parenti.) - Changes to past time stamps + Changes to past timestamps For America/Los_Angeles, spring-forward transition times have been corrected from 02:00 to 02:01 in 1948, and from 02:00 to 01:00 in @@ -658,9 +1025,9 @@ Release 2016g - 2016-09-13 08:56:38 -0700 zic no longer generates binary files containing POSIX TZ-like strings that disagree with the local time type after the last explicit transition in the data. This fixes a bug with - Africa/Casablanca and Africa/El_Aaiun in some year-2037 time - stamps on the reference platform. (Thanks to Alexander Belopolsky - for reporting the bug and suggesting a way forward.) + Africa/Casablanca and Africa/El_Aaiun in some year-2037 timestamps + on the reference platform. (Thanks to Alexander Belopolsky for + reporting the bug and suggesting a way forward.) If the installed localtime and/or posixrules files are symbolic links, zic now keeps them symbolic links when updating them, for @@ -723,7 +1090,7 @@ Release 2016g - 2016-09-13 08:56:38 -0700 Release 2016f - 2016-07-05 16:26:51 +0200 - Changes affecting future time stamps + Changes affecting future timestamps The Egyptian government changed its mind on short notice, and Africa/Cairo will not introduce DST starting 2016-07-07 after all. @@ -732,12 +1099,12 @@ Release 2016f - 2016-07-05 16:26:51 +0200 Asia/Novosibirsk switches from +06 to +07 on 2016-07-24 at 02:00. (Thanks to Stepan Golosunov.) - Changes to past and future time stamps + Changes to past and future timestamps Asia/Novokuznetsk and Asia/Novosibirsk now use numeric time zone abbreviations instead of invented ones. - Changes affecting past time stamps + Changes affecting past timestamps Europe/Minsk's 1992-03-29 spring-forward transition was at 02:00 not 00:00. (Thanks to Stepan Golosunov.) @@ -745,14 +1112,14 @@ Release 2016f - 2016-07-05 16:26:51 +0200 Release 2016e - 2016-06-14 08:46:16 -0700 - Changes affecting future time stamps + Changes affecting future timestamps Africa/Cairo observes DST in 2016 from July 7 to the end of October. Guess October 27 and 24:00 transitions. (Thanks to Steffen Thorsen.) For future years, guess April's last Thursday to October's last Thursday except for Ramadan. - Changes affecting past time stamps + Changes affecting past timestamps Locations while uninhabited now use '-00', not 'zzz', as a placeholder time zone abbreviation. This is inspired by Internet @@ -781,7 +1148,7 @@ Release 2016e - 2016-06-14 08:46:16 -0700 Release 2016d - 2016-04-17 22:50:29 -0700 - Changes affecting future time stamps + Changes affecting future timestamps America/Caracas switches from -0430 to -04 on 2016-05-01 at 02:30. (Thanks to Alexander Krivenyshev for the heads-up.) @@ -793,7 +1160,7 @@ Release 2016d - 2016-04-17 22:50:29 -0700 Tomsk Oblast, Russia, which switches from +06 to +07 on 2016-05-29 at 02:00. (Thanks to Stepan Golosunov.) - Changes affecting past time stamps + Changes affecting past timestamps New zone Europe/Kirov, split off from Europe/Volgograd. It covers Kirov Oblast, Russia, which switched from +04/+05 to +03/+04 on @@ -816,7 +1183,7 @@ Release 2016d - 2016-04-17 22:50:29 -0700 Release 2016c - 2016-03-23 00:51:27 -0700 - Changes affecting future time stamps + Changes affecting future timestamps Azerbaijan no longer observes DST. (Thanks to Steffen Thorsen.) @@ -827,7 +1194,7 @@ Release 2016c - 2016-03-23 00:51:27 -0700 2014-09-07 through 2016-05-14 daylight saving time instead of standard time, as that seems more appropriate now. - Changes affecting past time stamps + Changes affecting past timestamps Europe/Kaliningrad and Europe/Vilnius changed from +03/+04 to +02/+03 on 1989-03-26, not 1991-03-31. Europe/Volgograd changed @@ -852,7 +1219,7 @@ Release 2016b - 2016-03-12 17:30:14 -0800 POSIX.1-1988 that was removed in POSIX.1-2001. One way to suppress the warnings is to upgrade to zic derived from tz releases 2015f and later. - Changes affecting future time stamps + Changes affecting future timestamps New zones Europe/Astrakhan and Europe/Ulyanovsk for Astrakhan and Ulyanovsk Oblasts, Russia, both of which will switch from +03 to +04 on @@ -876,7 +1243,7 @@ Release 2016b - 2016-03-12 17:30:14 -0800 (Thanks to Hannah Kreitem.) Guess future transitions will be March's last Saturday at 01:00, not March's last Friday at 24:00. - Changes affecting past time stamps + Changes affecting past timestamps Europe/Chisinau observed DST during 1990, and switched from +04 to +03 at 1990-05-06 02:00, instead of switching from +03 to +02. @@ -900,7 +1267,7 @@ Release 2016b - 2016-03-12 17:30:14 -0800 Comments in zone tables have been improved. (Thanks to J William Piggott.) tzselect again limits its menu comments so that menus fit on a - 24x80 alphanumeric display. + 24×80 alphanumeric display. A new web page tz-how-to.html. (Thanks to Bill Seymour.) @@ -911,7 +1278,7 @@ Release 2016b - 2016-03-12 17:30:14 -0800 Release 2016a - 2016-01-26 23:28:02 -0800 - Changes affecting future time stamps + Changes affecting future timestamps America/Cayman will not observe daylight saving this year after all. Revert our guess that it would. (Thanks to Matt Johnson.) @@ -923,7 +1290,7 @@ Release 2016a - 2016-01-26 23:28:02 -0800 to be March 21 00:00 to September 21 00:00. This is likely better than predicting no DST, albeit off by a day every now and then. - Changes affecting past and future time stamps + Changes affecting past and future timestamps America/Metlakatla switched from PST all year to AKST/AKDT on 2015-11-01 at 02:00. (Thanks to Steffen Thorsen.) @@ -932,7 +1299,7 @@ Release 2016a - 2016-01-26 23:28:02 -0800 backward compatibility link to America/Tijuana. Its contents were apparently based on a misreading of Mexican legislation. - Changes affecting past time stamps + Changes affecting past timestamps Asia/Karachi's two transition times in 2002 were off by a minute. (Thanks to Matt Johnson.) @@ -966,7 +1333,7 @@ Release 2016a - 2016-01-26 23:28:02 -0800 Release 2015g - 2015-10-01 00:39:51 -0700 - Changes affecting future time stamps + Changes affecting future timestamps Turkey's 2015 fall-back transition is scheduled for Nov. 8, not Oct. 25. (Thanks to Fatih.) @@ -981,7 +1348,7 @@ Release 2015g - 2015-10-01 00:39:51 -0700 effectively been on MST (-0700) since it advanced its clocks on 2015-03-08. New zone America/Fort_Nelson. (Thanks to Matt Johnson.) - Changes affecting past time stamps + Changes affecting past timestamps Norfolk observed DST from 1974-10-27 02:00 to 1975-03-02 02:00. @@ -1011,7 +1378,7 @@ Release 2015g - 2015-10-01 00:39:51 -0700 Release 2015f - 2015-08-10 18:06:56 -0700 - Changes affecting future time stamps + Changes affecting future timestamps North Korea switches to +0830 on 2015-08-15. (Thanks to Steffen Thorsen.) The abbreviation remains "KST". (Thanks to Robert Elz.) @@ -1019,7 +1386,7 @@ Release 2015f - 2015-08-10 18:06:56 -0700 Uruguay no longer observes DST. (Thanks to Steffen Thorsen and Pablo Camargo.) - Changes affecting past and future time stamps + Changes affecting past and future timestamps Moldova starts and ends DST at 00:00 UTC, not at 01:00 UTC. (Thanks to Roman Tudos.) @@ -1078,7 +1445,7 @@ Release 2015f - 2015-08-10 18:06:56 -0700 Release 2015e - 2015-06-13 10:56:02 -0700 - Changes affecting future time stamps + Changes affecting future timestamps Morocco will suspend DST from 2015-06-14 03:00 through 2015-07-19 02:00, not 06-13 and 07-18 as we had guessed. (Thanks to Milamber.) @@ -1106,13 +1473,13 @@ Release 2015e - 2015-06-13 10:56:02 -0700 Release 2015d - 2015-04-24 08:09:46 -0700 - Changes affecting future time stamps + Changes affecting future timestamps Egypt will not observe DST in 2015 and will consider canceling it permanently. For now, assume no DST indefinitely. (Thanks to Ahmed Nazmy and Tim Parenti.) - Changes affecting past time stamps + Changes affecting past timestamps America/Whitehorse switched from UT -09 to -08 on 1967-05-28, not 1966-07-01. Also, Yukon's time zone history is documented better. @@ -1132,16 +1499,16 @@ Release 2015d - 2015-04-24 08:09:46 -0700 Release 2015c - 2015-04-11 08:55:55 -0700 - Changes affecting future time stamps + Changes affecting future timestamps Egypt's spring-forward transition is at 24:00 on April's last Thursday, not 00:00 on April's last Friday. 2015's transition will therefore be on Thursday, April 30 at 24:00, not Friday, April 24 at 00:00. Similar fixes apply to 2026, 2037, 2043, etc. (Thanks to Steffen Thorsen.) - Changes affecting past time stamps + Changes affecting past timestamps - The following changes affect some pre-1991 Chile-related time stamps + The following changes affect some pre-1991 Chile-related timestamps in America/Santiago, Antarctica/Palmer, and Pacific/Easter. The 1910 transition was January 10, not January 1. @@ -1166,8 +1533,8 @@ Release 2015c - 2015-04-11 08:55:55 -0700 since we have no data suggesting that they existed. One more zone has been turned into a link, as it differed - from an existing zone only for older time stamps. As usual, - this change affects UT offsets in pre-1970 time stamps only. + from an existing zone only for older timestamps. As usual, + this change affects UT offsets in pre-1970 timestamps only. The zone's old contents have been moved to the 'backzone' file. The affected zone is America/Montreal. @@ -1180,7 +1547,7 @@ Release 2015c - 2015-04-11 08:55:55 -0700 Release 2015b - 2015-03-19 23:28:11 -0700 - Changes affecting future time stamps + Changes affecting future timestamps Mongolia will start observing DST again this year, from the last Saturday in March at 02:00 to the last Saturday in September at 00:00. @@ -1190,14 +1557,14 @@ Release 2015b - 2015-03-19 23:28:11 -0700 correct the fall 2014 transition from September 26 to October 24. Adjust future predictions accordingly. (Thanks to Steffen Thorsen.) - Changes affecting past time stamps + Changes affecting past timestamps The 1982 zone shift in Pacific/Easter has been corrected, fixing a 2015a regression. (Thanks to Stuart Bishop for reporting the problem.) Some more zones have been turned into links, when they differed - from existing zones only for older time stamps. As usual, - these changes affect UT offsets in pre-1970 time stamps only. + from existing zones only for older timestamps. As usual, + these changes affect UT offsets in pre-1970 timestamps only. Their old contents have been moved to the 'backzone' file. The affected zones are: America/Antigua, America/Cayman, Pacific/Midway, and Pacific/Saipan. @@ -1228,7 +1595,7 @@ Release 2015b - 2015-03-19 23:28:11 -0700 Release 2015a - 2015-01-29 22:35:20 -0800 - Changes affecting future time stamps + Changes affecting future timestamps The Mexican state of Quintana Roo, represented by America/Cancun, will shift from Central Time with DST to Eastern Time without DST @@ -1241,15 +1608,15 @@ Release 2015a - 2015-01-29 22:35:20 -0800 New leap second 2015-06-30 23:59:60 UTC as per IERS Bulletin C 49. (Thanks to Tim Parenti.) - Changes affecting past time stamps + Changes affecting past timestamps Iceland observed DST in 1919 and 1921, and its 1939 fallback transition was Oct. 29, not Nov. 29. Remove incorrect data from Shanks about time in Iceland between 1837 and 1908. Some more zones have been turned into links, when they differed - from existing zones only for older time stamps. As usual, - these changes affect UT offsets in pre-1970 time stamps only. + from existing zones only for older timestamps. As usual, + these changes affect UT offsets in pre-1970 timestamps only. Their old contents have been moved to the 'backzone' file. The affected zones are: Asia/Aden, Asia/Bahrain, Asia/Kuwait, and Asia/Muscat. @@ -1280,23 +1647,23 @@ Release 2015a - 2015-01-29 22:35:20 -0800 Release 2014j - 2014-11-10 17:37:11 -0800 - Changes affecting current and future time stamps + Changes affecting current and future timestamps Turks & Caicos' switch from US eastern time to UT -04 year-round did not occur on 2014-11-02 at 02:00. It's currently scheduled for 2015-11-01 at 02:00. (Thanks to Chris Walton.) - Changes affecting past time stamps + Changes affecting past timestamps - Many pre-1989 time stamps have been corrected for Asia/Seoul and + Many pre-1989 timestamps have been corrected for Asia/Seoul and Asia/Pyongyang, based on sources for the Korean-language Wikipedia entry for time in Korea. (Thanks to Sanghyuk Jung.) Also, no longer guess that Pyongyang mimicked Seoul time after World War II, as this is politically implausible. Some more zones have been turned into links, when they differed - from existing zones only for older time stamps. As usual, - these changes affect UT offsets in pre-1970 time stamps only. + from existing zones only for older timestamps. As usual, + these changes affect UT offsets in pre-1970 timestamps only. Their old contents have been moved to the 'backzone' file. The affected zones are: Africa/Addis_Ababa, Africa/Asmara, Africa/Dar_es_Salaam, Africa/Djibouti, Africa/Kampala, @@ -1311,7 +1678,7 @@ Release 2014j - 2014-11-10 17:37:11 -0800 Release 2014i - 2014-10-21 22:04:57 -0700 - Changes affecting future time stamps + Changes affecting future timestamps Pacific/Fiji will observe DST from 2014-11-02 02:00 to 2015-01-18 03:00. (Thanks to Ken Rylander for the heads-up.) Guess that future @@ -1331,17 +1698,17 @@ Release 2014i - 2014-10-21 22:04:57 -0700 The new abbreviation IDT stands for the pre-1976 use of UT +08 in Indochina, to distinguish it better from ICT (+07). - Changes affecting past time stamps + Changes affecting past timestamps - Many time stamps have been corrected for Asia/Ho_Chi_Minh before 1976 + Many timestamps have been corrected for Asia/Ho_Chi_Minh before 1976 (thanks to Trần Ngọc Quân for an indirect pointer to Trần Tiến Bình's authoritative book). Asia/Ho_Chi_Minh has been added to zone1970.tab, to give tzselect users in Vietnam two choices, since north and south Vietnam disagreed after our 1970 cutoff. Asia/Phnom_Penh and Asia/Vientiane have been turned into links, as - they differed from existing zones only for older time stamps. As - usual, these changes affect pre-1970 time stamps only. Their old + they differed from existing zones only for older timestamps. As + usual, these changes affect pre-1970 timestamps only. Their old contents have been moved to the 'backzone' file. Changes affecting code @@ -1481,7 +1848,7 @@ Release 2014g - 2014-08-28 12:31:23 -0700 Unless NETBSD_INSPIRED is defined to 0, the tz library now supplies functions for creating and using objects that represent - time zones. The new functions are tzalloc, tzfree, localtime_rz, + timezones. The new functions are tzalloc, tzfree, localtime_rz, mktime_z, and (if STD_INSPIRED is also defined) posix2time_z and time2posix_z. They are intended for performance: for example, localtime_rz (unlike localtime_r) is trivially thread-safe without @@ -1495,7 +1862,7 @@ Release 2014g - 2014-08-28 12:31:23 -0700 TZDOBJS=zdump.o CHECK_TIME_T_ALTERNATIVES='. zdump now uses localtime_rz if available, as it's significantly faster, - and it can help zdump better diagnose invalid time zone names. + and it can help zdump better diagnose invalid timezone names. Define HAVE_LOCALTIME_RZ to 0 to suppress this. HAVE_LOCALTIME_RZ defaults to 1 if NETBSD_INSPIRED && USE_LTZ. When localtime_rz is not available, zdump now uses localtime_r and tzset if available, @@ -1511,7 +1878,7 @@ Release 2014g - 2014-08-28 12:31:23 -0700 invalid or outlandish input. The tz library no longer mishandles leap seconds on platforms with - unsigned time_t in time zones that lack ordinary transitions after 1970. + unsigned time_t in timezones that lack ordinary transitions after 1970. The tz code now attempts to infer TM_GMTOFF and TM_ZONE if not already defined, to make it easier to configure on common platforms. @@ -1835,8 +2202,8 @@ Release 2014d - 2014-05-27 21:34:40 -0700 Changes affecting code zic no longer generates files containing timestamps before the Big Bang. - This works around GNOME bug 730332 - . + This works around GNOME glib bug 878 + (Thanks to Leonardo Chiquitto for reporting the bug, and to Arthur David Olson and James Cloos for suggesting improvements to the fix.) @@ -3289,7 +3656,7 @@ Release 2005j - 2005-06-13 14:34:13 -0400 These reflect changes to limit the length of time zone abbreviations and the characters used in those abbreviations. - There are also changes to handle POSIX-style "quoted" time zone + There are also changes to handle POSIX-style "quoted" timezone environment variables. The changes were circulated on the time zone mailing list; the only @@ -3615,7 +3982,7 @@ Release 1999f - 1999-09-23 09:48:14 -0400 Release 1999e - 1999-08-17 15:20:54 -0400 changes circulated by Paul Eggert, although the change to handling - of DST-specifying time zone names has been commented out for now + of DST-specifying timezone names has been commented out for now (search for "XXX" in "localtime.c" for details). These files also do not make any changes to the start of DST in Brazil. @@ -3740,7 +4107,7 @@ Release code1997i-data1997k - 1997-12-29 09:53:41 -0500 Release code1997h-data1997j - 1997-12-18 17:47:35 -0500 - minor changes to put "TZif" at the start of each time zone information file + minor changes to put "TZif" at the start of each timezone information file a rule has also been added to the Makefile so you can make zones @@ -4250,8 +4617,8 @@ consisting of a single tarball tzdb-R.tar.lz with extra data. Release timestamps are taken from the release's commit (for newer, Git-based releases), from the newest file in the tarball (for older releases, where this info is available) or from the email announcing -the release (if all else fails; these are marked with a time zone of --0000 and an "is missing!" comment). +the release (if all else fails; these are marked with a time zone +abbreviation of -0000 and an "is missing!" comment). Earlier versions of the code and data were not announced on the tz list and are not summarized here. diff --git a/contrib/tzdata/README b/contrib/tzdata/README index ab8e47b63e..efe7a17f21 100644 --- a/contrib/tzdata/README +++ b/contrib/tzdata/README @@ -4,7 +4,7 @@ README for the tz distribution "Any time you want it to be." -- Frank Baxter as The Scientist (from the Bell System film "About Time") -The Time Zone Database (often called tz or zoneinfo) contains code and +The Time Zone Database (called tz, tzdb or zoneinfo) contains code and data that represent the history of local time for many representative locations around the globe. It is updated periodically to reflect changes made by political bodies to time zone boundaries, UTC offsets, @@ -20,17 +20,15 @@ substituting your desired installation directory for "$HOME/tzdir": make TOPDIR=$HOME/tzdir install $HOME/tzdir/usr/bin/zdump -v America/Los_Angeles -Historical local time information has been included here to: +This database of historical local time information has several goals: -* provide a compendium of data about the history of civil time - that is useful even if not 100% accurate; + * Provide a compendium of data about the history of civil time that + is useful even if not 100% accurate. -* give an idea of the variety of local time rules that have - existed in the past and thus an idea of the variety that may be - expected in the future; + * Give an idea of the variety of local time rules that have existed + in the past and thus may be expected in the future. -* provide a test of the generality of the local time rule description - system. + * Test the generality of the local time rule description system. The information in the time zone data files is by no means authoritative; fixes and enhancements are welcome. Please see the file CONTRIBUTING diff --git a/contrib/tzdata/africa b/contrib/tzdata/africa index 02115ad615..a26b91bc11 100644 --- a/contrib/tzdata/africa +++ b/contrib/tzdata/africa @@ -1,3 +1,5 @@ +# tzdb data for Africa and environs + # This file is in the public domain, so clarified as of # 2009-05-17 by Arthur David Olson. @@ -6,7 +8,7 @@ # tz@iana.org for general use in the future). For more, please see # the file CONTRIBUTING in the tz distribution. -# From Paul Eggert (2017-02-20): +# From Paul Eggert (2018-05-27): # # Unless otherwise specified, the source for data through 1990 is: # Thomas G. Shanks and Rique Pottenger, The International Atlas (6th edition), @@ -51,13 +53,15 @@ # I vaguely recall 'WAT' also being used for -01 in the past but # cannot now come up with solid citations. # -# I invented the following abbreviations; corrections are welcome! +# I invented the following abbreviations in the 1990s: # +02 WAST West Africa Summer Time -# +03 CAST Central Africa Summer Time (no longer used) -# +03 SAST South Africa Summer Time (no longer used) +# +03 CAST Central Africa Summer Time +# +03 SAST South Africa Summer Time # +03 EAT East Africa Time -# 'EAT' also seems to have caught on; the others are rare but are paired -# with better-attested non-DST abbreviations. +# 'EAT' seems to have caught on and is in current timestamps, and though +# the other abbreviations are rarer and are only in past timestamps, +# they are paired with better-attested non-DST abbreviations. +# Corrections are welcome. # Algeria # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S @@ -115,13 +119,13 @@ Zone Africa/Algiers 0:12:12 - LMT 1891 Mar 15 0:01 # Cape Verde / Cabo Verde # +# From Paul Eggert (2018-02-16): # Shanks gives 1907 for the transition to +02. -# Perhaps the 1911-05-26 Portuguese decree -# https://dre.pt/pdf1sdip/1911/05/12500/23132313.pdf -# merely made it official? +# For now, ignore that and follow the 1911-05-26 Portuguese decree +# (see Europe/Lisbon). # # Zone NAME GMTOFF RULES FORMAT [UNTIL] -Zone Atlantic/Cape_Verde -1:34:04 - LMT 1907 # Praia +Zone Atlantic/Cape_Verde -1:34:04 - LMT 1912 Jan 01 2:00u # Praia -2:00 - -02 1942 Sep -2:00 1:00 -01 1945 Oct 15 -2:00 - -02 1975 Nov 25 2:00 @@ -362,6 +366,13 @@ Zone Africa/Cairo 2:05:09 - LMT 1900 Oct # Eritrea # Ethiopia # See Africa/Nairobi. +# +# Unfortunately tzdb records only Western clock time in use in Ethiopia, +# as the tzdb format is not up to properly recording a common Ethiopian +# timekeeping practice that is based on solar time. See: +# Mortada D. If you have a meeting in Ethiopia, you'd better double +# check the time. PRI's The World. 2015-01-30 15:15 -05. +# https://www.pri.org/stories/2015-01-30/if-you-have-meeting-ethiopia-you-better-double-check-time # Gabon # See Africa/Lagos. @@ -370,15 +381,34 @@ Zone Africa/Cairo 2:05:09 - LMT 1900 Oct # See Africa/Abidjan. # Ghana -# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S + +# From Paul Eggert (2018-01-30): # Whitman says DST was observed from 1931 to "the present"; -# Shanks & Pottenger say 1936 to 1942; -# and September 1 to January 1 is given by: -# Scott Keltie J, Epstein M (eds), The Statesman's Year-Book, -# 57th ed. Macmillan, London (1920), OCLC 609408015, pp xxviii. -# For lack of better info, assume DST was observed from 1920 to 1942. -Rule Ghana 1920 1942 - Sep 1 0:00 0:20 GHST -Rule Ghana 1920 1942 - Dec 31 0:00 0 GMT +# Shanks & Pottenger say 1936 to 1942 with 20 minutes of DST, +# with transitions on 09-01 and 12-31 at 00:00. +# Page 33 of Parish GCB, Colonial Reports - Annual. No. 1066. Gold +# Coast. Report for 1919. (March 1921), OCLC 784024077 +# http://libsysdigi.library.illinois.edu/ilharvest/africana/books2011-05/5530214/5530214_1919/5530214_1919_opt.pdf +# lists the Determination of the Time Ordinance, 1919, No. 18, +# "to advance the time observed locally by the space of twenty minutes +# during the last four months of each year; the object in view being +# to extend during those months the period of daylight-time available +# for evening recreation after office hours." +# Vanessa Ogle, The Global Transformation of Time, 1870-1950 (2015), p 33, +# writes "In 1919, the Gold Coast (Ghana as of 1957) made Greenwich +# time its legal time and simultaneously legalized a summer time of +# UTC - 00:20 minutes from March to October."; a footnote lists +# the ordinance as being dated 1919-11-24. +# The Crown Colonist, Volume 12 (1942), p 176, says "the Government +# intend advancing Gold Coast time half an hour ahead of G.M.T. +# The actual date of the alteration has not yet been announced." +# These sources are incomplete and contradictory. Possibly what is +# now Ghana observed different DST regimes in different years. For +# lack of better info, use Shanks except treat the minus sign as a +# typo, and assume DST started in 1920 not 1936. +# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S +Rule Ghana 1920 1942 - Sep 1 0:00 0:20 - +Rule Ghana 1920 1942 - Dec 31 0:00 0 - # Zone NAME GMTOFF RULES FORMAT [UNTIL] Zone Africa/Accra -0:00:52 - LMT 1918 0:00 Ghana GMT/+0020 @@ -388,13 +418,13 @@ Zone Africa/Accra -0:00:52 - LMT 1918 # Guinea-Bissau # +# From Paul Eggert (2018-02-16): # Shanks gives 1911-05-26 for the transition to WAT, # evidently confusing the date of the Portuguese decree -# https://dre.pt/pdf1sdip/1911/05/12500/23132313.pdf -# with the date that it took effect, namely 1912-01-01. +# (see Europe/Lisbon) with the date that it took effect. # # Zone NAME GMTOFF RULES FORMAT [UNTIL] -Zone Africa/Bissau -1:02:20 - LMT 1912 Jan 1 +Zone Africa/Bissau -1:02:20 - LMT 1912 Jan 1 1:00u -1:00 - -01 1975 0:00 - GMT @@ -590,9 +620,9 @@ Zone Africa/Tripoli 0:52:44 - LMT 1920 # at 2am (or 02:00) local time..." # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S -Rule Mauritius 1982 only - Oct 10 0:00 1:00 S +Rule Mauritius 1982 only - Oct 10 0:00 1:00 - Rule Mauritius 1983 only - Mar 21 0:00 0 - -Rule Mauritius 2008 only - Oct lastSun 2:00 1:00 S +Rule Mauritius 2008 only - Oct lastSun 2:00 1:00 - Rule Mauritius 2009 only - Mar lastSun 2:00 0 - # Zone NAME GMTOFF RULES FORMAT [UNTIL] Zone Indian/Mauritius 3:50:00 - LMT 1907 # Port Louis @@ -814,94 +844,61 @@ Zone Indian/Mauritius 3:50:00 - LMT 1907 # Port Louis # agrees # with the patch. -# From Paul Eggert (2015-06-08): -# For now, guess that later spring and fall transitions will use 2015's rules, -# and guess that Morocco will switch to standard time at 03:00 the last -# Sunday before Ramadan, and back to DST at 02:00 the first Sunday after -# Ramadan. To implement this, transition dates for 2016 through 2037 were -# determined by running the following program under GNU Emacs 24.3, with the -# results integrated by hand into the table below. -# (let ((islamic-year 1437)) -# (require 'cal-islam) -# (while (< islamic-year 1460) -# (let ((a (calendar-islamic-to-absolute (list 9 1 islamic-year))) -# (b (calendar-islamic-to-absolute (list 10 1 islamic-year))) -# (sunday 0)) -# (while (/= sunday (mod (setq a (1- a)) 7))) -# (while (/= sunday (mod b 7)) -# (setq b (1+ b))) -# (setq a (calendar-gregorian-from-absolute a)) -# (setq b (calendar-gregorian-from-absolute b)) -# (insert -# (format -# (concat "Rule\tMorocco\t%d\tonly\t-\t%s\t%2d\t 3:00\t0\t-\n" -# "Rule\tMorocco\t%d\tonly\t-\t%s\t%2d\t 2:00\t1:00\tS\n") -# (car (cdr (cdr a))) (calendar-month-name (car a) t) (car (cdr a)) -# (car (cdr (cdr b))) (calendar-month-name (car b) t) (car (cdr b))))) -# (setq islamic-year (+ 1 islamic-year)))) +# From Mohamed Essedik Najd (2018-10-26): +# Today, a Moroccan government council approved the perpetual addition +# of 60 minutes to the regular Moroccan timezone. +# From Brian Inglis (2018-10-26): +# http://www.maroc.ma/fr/actualites/le-conseil-de-gouvernement-adopte-un-projet-de-decret-relatif-lheure-legale-stipulant-le # RULE NAME FROM TO TYPE IN ON AT SAVE LETTER/S - -Rule Morocco 1939 only - Sep 12 0:00 1:00 S +Rule Morocco 1939 only - Sep 12 0:00 1:00 - Rule Morocco 1939 only - Nov 19 0:00 0 - -Rule Morocco 1940 only - Feb 25 0:00 1:00 S +Rule Morocco 1940 only - Feb 25 0:00 1:00 - Rule Morocco 1945 only - Nov 18 0:00 0 - -Rule Morocco 1950 only - Jun 11 0:00 1:00 S +Rule Morocco 1950 only - Jun 11 0:00 1:00 - Rule Morocco 1950 only - Oct 29 0:00 0 - -Rule Morocco 1967 only - Jun 3 12:00 1:00 S +Rule Morocco 1967 only - Jun 3 12:00 1:00 - Rule Morocco 1967 only - Oct 1 0:00 0 - -Rule Morocco 1974 only - Jun 24 0:00 1:00 S +Rule Morocco 1974 only - Jun 24 0:00 1:00 - Rule Morocco 1974 only - Sep 1 0:00 0 - -Rule Morocco 1976 1977 - May 1 0:00 1:00 S +Rule Morocco 1976 1977 - May 1 0:00 1:00 - Rule Morocco 1976 only - Aug 1 0:00 0 - Rule Morocco 1977 only - Sep 28 0:00 0 - -Rule Morocco 1978 only - Jun 1 0:00 1:00 S +Rule Morocco 1978 only - Jun 1 0:00 1:00 - Rule Morocco 1978 only - Aug 4 0:00 0 - -Rule Morocco 2008 only - Jun 1 0:00 1:00 S +Rule Morocco 2008 only - Jun 1 0:00 1:00 - Rule Morocco 2008 only - Sep 1 0:00 0 - -Rule Morocco 2009 only - Jun 1 0:00 1:00 S +Rule Morocco 2009 only - Jun 1 0:00 1:00 - Rule Morocco 2009 only - Aug 21 0:00 0 - -Rule Morocco 2010 only - May 2 0:00 1:00 S +Rule Morocco 2010 only - May 2 0:00 1:00 - Rule Morocco 2010 only - Aug 8 0:00 0 - -Rule Morocco 2011 only - Apr 3 0:00 1:00 S +Rule Morocco 2011 only - Apr 3 0:00 1:00 - Rule Morocco 2011 only - Jul 31 0:00 0 - -Rule Morocco 2012 2013 - Apr lastSun 2:00 1:00 S +Rule Morocco 2012 2013 - Apr lastSun 2:00 1:00 - Rule Morocco 2012 only - Jul 20 3:00 0 - -Rule Morocco 2012 only - Aug 20 2:00 1:00 S +Rule Morocco 2012 only - Aug 20 2:00 1:00 - Rule Morocco 2012 only - Sep 30 3:00 0 - Rule Morocco 2013 only - Jul 7 3:00 0 - -Rule Morocco 2013 only - Aug 10 2:00 1:00 S -Rule Morocco 2013 max - Oct lastSun 3:00 0 - -Rule Morocco 2014 2021 - Mar lastSun 2:00 1:00 S +Rule Morocco 2013 only - Aug 10 2:00 1:00 - +Rule Morocco 2013 2018 - Oct lastSun 3:00 0 - +Rule Morocco 2014 2018 - Mar lastSun 2:00 1:00 - Rule Morocco 2014 only - Jun 28 3:00 0 - -Rule Morocco 2014 only - Aug 2 2:00 1:00 S +Rule Morocco 2014 only - Aug 2 2:00 1:00 - Rule Morocco 2015 only - Jun 14 3:00 0 - -Rule Morocco 2015 only - Jul 19 2:00 1:00 S +Rule Morocco 2015 only - Jul 19 2:00 1:00 - Rule Morocco 2016 only - Jun 5 3:00 0 - -Rule Morocco 2016 only - Jul 10 2:00 1:00 S +Rule Morocco 2016 only - Jul 10 2:00 1:00 - Rule Morocco 2017 only - May 21 3:00 0 - -Rule Morocco 2017 only - Jul 2 2:00 1:00 S +Rule Morocco 2017 only - Jul 2 2:00 1:00 - Rule Morocco 2018 only - May 13 3:00 0 - -Rule Morocco 2018 only - Jun 17 2:00 1:00 S -Rule Morocco 2019 only - May 5 3:00 0 - -Rule Morocco 2019 only - Jun 9 2:00 1:00 S -Rule Morocco 2020 only - Apr 19 3:00 0 - -Rule Morocco 2020 only - May 24 2:00 1:00 S -Rule Morocco 2021 only - Apr 11 3:00 0 - -Rule Morocco 2021 only - May 16 2:00 1:00 S -Rule Morocco 2022 only - May 8 2:00 1:00 S -Rule Morocco 2023 only - Apr 23 2:00 1:00 S -Rule Morocco 2024 only - Apr 14 2:00 1:00 S -Rule Morocco 2025 only - Apr 6 2:00 1:00 S -Rule Morocco 2026 max - Mar lastSun 2:00 1:00 S -Rule Morocco 2036 only - Oct 19 3:00 0 - -Rule Morocco 2037 only - Oct 4 3:00 0 - +Rule Morocco 2018 only - Jun 17 2:00 1:00 - # Zone NAME GMTOFF RULES FORMAT [UNTIL] Zone Africa/Casablanca -0:30:20 - LMT 1913 Oct 26 - 0:00 Morocco WE%sT 1984 Mar 16 - 1:00 - CET 1986 - 0:00 Morocco WE%sT + 0:00 Morocco +00/+01 1984 Mar 16 + 1:00 - +01 1986 + 0:00 Morocco +00/+01 2018 Oct 27 + 1:00 - +01 # Western Sahara # @@ -916,7 +913,8 @@ Zone Africa/Casablanca -0:30:20 - LMT 1913 Oct 26 Zone Africa/El_Aaiun -0:52:48 - LMT 1934 Jan # El Aaiún -1:00 - -01 1976 Apr 14 - 0:00 Morocco WE%sT + 0:00 Morocco +00/+01 2018 Oct 27 + 1:00 - +01 # Mozambique # @@ -948,6 +946,10 @@ Link Africa/Maputo Africa/Lusaka # Zambia # commence at OOhOO on Monday 21 March 1994 and shall end at 02h00 on # Sunday 4 September 1994. +# From Michael Deckers (2017-04-06): +# ... both summer and winter time are called "standard" +# (which differs from the use in Ireland) ... + # From Petronella Sibeene (2007-03-30): # http://allafrica.com/stories/200703300178.html # While the entire country changes its time, Katima Mulilo and other @@ -973,19 +975,42 @@ Link Africa/Maputo Africa/Lusaka # Zambia # the same time they would normally start DST, the first Sunday in September: # https://www.timeanddate.com/news/time/namibia-new-time-zone.html +# From Paul Eggert (2017-04-09): +# Before the change, summer and winter time were both standard time legally. +# However in common parlance, winter time was considered to be DST. See, e.g.: +# http://www.nbc.na/news/namibias-winter-time-could-be-scrapped.2706 +# https://zone.my.na/news/times-are-changing-in-namibia +# https://www.newera.com.na/2017/02/23/namibias-winter-time-might-be-repealed/ +# Use plain "WAT" and "CAT" for the time zone abbreviations, to be compatible +# with Namibia's neighbors. + # RULE NAME FROM TO TYPE IN ON AT SAVE LETTER/S -Rule Namibia 1994 only - Mar 21 0:00 0 - -Rule Namibia 1994 2016 - Sep Sun>=1 2:00 1:00 S -Rule Namibia 1995 2017 - Apr Sun>=1 2:00 0 - +# Vanguard section, for zic and other parsers that support negative DST. +Rule Namibia 1994 only - Mar 21 0:00 -1:00 WAT +Rule Namibia 1994 2017 - Sep Sun>=1 2:00 0 CAT +Rule Namibia 1995 2017 - Apr Sun>=1 2:00 -1:00 WAT +# Rearguard section, for parsers that do not support negative DST. +#Rule Namibia 1994 only - Mar 21 0:00 0 WAT +#Rule Namibia 1994 2017 - Sep Sun>=1 2:00 1:00 CAT +#Rule Namibia 1995 2017 - Apr Sun>=1 2:00 0 WAT +# End of rearguard section. + # Zone NAME GMTOFF RULES FORMAT [UNTIL] Zone Africa/Windhoek 1:08:24 - LMT 1892 Feb 8 1:30 - +0130 1903 Mar 2:00 - SAST 1942 Sep 20 2:00 2:00 1:00 SAST 1943 Mar 21 2:00 2:00 - SAST 1990 Mar 21 # independence - 2:00 - CAT 1994 Mar 21 0:00 - 1:00 Namibia WA%sT 2017 Sep 3 2:00 - 2:00 - CAT +# Vanguard section, for zic and other parsers that support negative DST. + 2:00 Namibia %s +# Rearguard section, for parsers that do not support negative DST. +# 2:00 - CAT 1994 Mar 21 0:00 +# From Paul Eggert (2017-04-07): +# The official date of the 2017 rule change was 2017-10-24. See: +# http://www.lac.org.na/laws/annoSTAT/Namibian%20Time%20Act%209%20of%202017.pdf +# 1:00 Namibia %s 2017 Oct 24 +# 2:00 - CAT +# End of rearguard section. # Niger # See Africa/Lagos. @@ -1037,6 +1062,8 @@ Zone Indian/Reunion 3:41:52 - LMT 1911 Jun # Saint-Denis # São Tomé and Príncipe +# See Europe/Lisbon for info about the 1912 transition. + # From Steffen Thorsen (2018-01-08): # Multiple sources tell that São Tomé changed from UTC to UTC+1 as # they entered the year 2018. @@ -1045,7 +1072,7 @@ Zone Indian/Reunion 3:41:52 - LMT 1911 Jun # Saint-Denis # http://www.mnec.gov.st/index.php/publicacoes/documentos/file/90-decreto-lei-n-25-2017 Zone Africa/Sao_Tome 0:26:56 - LMT 1884 - -0:36:45 - LMT 1912 # Lisbon Mean Time + -0:36:45 - LMT 1912 Jan 1 00:00u # Lisbon MT 0:00 - GMT 2018 Jan 1 01:00 1:00 - WAT diff --git a/contrib/tzdata/antarctica b/contrib/tzdata/antarctica index d9c132a30f..1dd9b004f7 100644 --- a/contrib/tzdata/antarctica +++ b/contrib/tzdata/antarctica @@ -1,3 +1,5 @@ +# tzdb data for Antarctica and environs + # This file is in the public domain, so clarified as of # 2009-05-17 by Arthur David Olson. @@ -75,7 +77,8 @@ Zone Antarctica/Casey 0 - -00 1969 8:00 - +08 2011 Oct 28 2:00 11:00 - +11 2012 Feb 21 17:00u 8:00 - +08 2016 Oct 22 - 11:00 - +11 + 11:00 - +11 2018 Mar 11 4:00 + 8:00 - +08 Zone Antarctica/Davis 0 - -00 1957 Jan 13 7:00 - +07 1964 Nov 0 - -00 1969 Feb diff --git a/contrib/tzdata/asia b/contrib/tzdata/asia index 3f6e95c201..48b4c65299 100644 --- a/contrib/tzdata/asia +++ b/contrib/tzdata/asia @@ -1,3 +1,5 @@ +# tzdb data for Asia and environs + # This file is in the public domain, so clarified as of # 2009-05-17 by Arthur David Olson. @@ -6,7 +8,7 @@ # tz@iana.org for general use in the future). For more, please see # the file CONTRIBUTING in the tz distribution. -# From Paul Eggert (2017-01-13): +# From Paul Eggert (2018-06-19): # # Unless otherwise specified, the source for data through 1990 is: # Thomas G. Shanks and Rique Pottenger, The International Atlas (6th edition), @@ -35,7 +37,8 @@ # A reliable and entertaining source about time zones is # Derek Howse, Greenwich time and longitude, Philip Wilson Publishers (1997). # -# The following alphabetic abbreviations appear in these tables: +# The following alphabetic abbreviations appear in these tables +# (corrections are welcome): # std dst # LMT Local Mean Time # 2:00 EET EEST Eastern European Time @@ -44,11 +47,13 @@ # 7:00 WIB west Indonesia (Waktu Indonesia Barat) # 8:00 WITA central Indonesia (Waktu Indonesia Tengah) # 8:00 CST China +# 8:00 PST PDT* Philippine Standard Time # 8:30 KST KDT Korea when at +0830 # 9:00 WIT east Indonesia (Waktu Indonesia Timur) # 9:00 JST JDT Japan # 9:00 KST KDT Korea when at +09 # 9:30 ACST Australian Central Standard Time +# *I invented the abbreviation PDT; see "Philippines" below. # Otherwise, these tables typically use numeric abbreviations like +03 # and +0330 for integer hour and minute UT offsets. Although earlier # editions invented alphabetic time zone abbreviations for every @@ -69,13 +74,13 @@ Rule EUAsia 1981 max - Mar lastSun 1:00u 1:00 S Rule EUAsia 1979 1995 - Sep lastSun 1:00u 0 - Rule EUAsia 1996 max - Oct lastSun 1:00u 0 - -Rule E-EurAsia 1981 max - Mar lastSun 0:00 1:00 S +Rule E-EurAsia 1981 max - Mar lastSun 0:00 1:00 - Rule E-EurAsia 1979 1995 - Sep lastSun 0:00 0 - Rule E-EurAsia 1996 max - Oct lastSun 0:00 0 - -Rule RussiaAsia 1981 1984 - Apr 1 0:00 1:00 S +Rule RussiaAsia 1981 1984 - Apr 1 0:00 1:00 - Rule RussiaAsia 1981 1983 - Oct 1 0:00 0 - Rule RussiaAsia 1984 1995 - Sep lastSun 2:00s 0 - -Rule RussiaAsia 1985 2010 - Mar lastSun 2:00s 1:00 S +Rule RussiaAsia 1985 2010 - Mar lastSun 2:00s 1:00 - Rule RussiaAsia 1996 2010 - Oct lastSun 2:00s 0 - # Afghanistan @@ -110,7 +115,7 @@ Zone Asia/Kabul 4:36:48 - LMT 1890 # (brief) # http://www.worldtimezone.com/dst_news/dst_news_armenia03.html # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S -Rule Armenia 2011 only - Mar lastSun 2:00s 1:00 S +Rule Armenia 2011 only - Mar lastSun 2:00s 1:00 - Rule Armenia 2011 only - Oct lastSun 2:00s 0 - # Zone NAME GMTOFF RULES FORMAT [UNTIL] Zone Asia/Yerevan 2:58:00 - LMT 1924 May 2 @@ -136,7 +141,7 @@ Zone Asia/Yerevan 2:58:00 - LMT 1924 May 2 # http://en.apa.az/xeber_azerbaijan_abolishes_daylight_savings_ti_240862.html # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S -Rule Azer 1997 2015 - Mar lastSun 4:00 1:00 S +Rule Azer 1997 2015 - Mar lastSun 4:00 1:00 - Rule Azer 1997 2015 - Oct lastSun 5:00 0 - # Zone NAME GMTOFF RULES FORMAT [UNTIL] Zone Asia/Baku 3:19:24 - LMT 1924 May 2 @@ -223,7 +228,7 @@ Zone Asia/Baku 3:19:24 - LMT 1924 May 2 # http://www.worldtimezone.com/dst_news/dst_news_bangladesh06.html # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S -Rule Dhaka 2009 only - Jun 19 23:00 1:00 S +Rule Dhaka 2009 only - Jun 19 23:00 1:00 - Rule Dhaka 2009 only - Dec 31 24:00 0 - # Zone NAME GMTOFF RULES FORMAT [UNTIL] @@ -281,6 +286,29 @@ Zone Asia/Yangon 6:24:47 - LMT 1880 # or Rangoon # China +# From Paul Eggert (2018-10-02): +# The following comes from Table 1 of: +# Li Yu. Research on the daylight saving movement in 1940s Shanghai. +# Nanjing Journal of Social Sciences. 2014;(2):144-50. +# http://oversea.cnki.net/kns55/detail.aspx?dbname=CJFD2014&filename=NJSH201402020 +# The table lists dates only; I am guessing 00:00 and 24:00 transition times. +# Also, the table lists the planned end of DST in 1949, but the corresponding +# zone line cuts this off on May 28, when the Communists took power. +# +# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S +Rule Shang 1940 only - Jun 1 0:00 1:00 D +Rule Shang 1940 only - Oct 12 24:00 0 S +Rule Shang 1941 only - Mar 15 0:00 1:00 D +Rule Shang 1941 only - Nov 1 24:00 0 S +Rule Shang 1942 only - Jan 31 0:00 1:00 D +Rule Shang 1945 only - Sep 1 24:00 0 S +Rule Shang 1946 only - May 15 0:00 1:00 D +Rule Shang 1946 only - Sep 30 24:00 0 S +Rule Shang 1947 only - Apr 15 0:00 1:00 D +Rule Shang 1947 only - Oct 31 24:00 0 S +Rule Shang 1948 1949 - May 1 0:00 1:00 D +Rule Shang 1948 1949 - Sep 30 24:00 0 S #plan + # From Guy Harris: # People's Republic of China. Yes, they really have only one time zone. @@ -307,18 +335,33 @@ Zone Asia/Yangon 6:24:47 - LMT 1880 # or Rangoon # time - sort of", Los Angeles Times, 1986-05-05 ... [says] that China began # observing daylight saving time in 1986. -# From Paul Eggert (2014-06-30): -# Shanks & Pottenger have China switching to a single time zone in 1980, but -# this doesn't seem to be correct. They also write that China observed summer -# DST from 1986 through 1991, which seems to match the above commentary, so -# go with them for DST rules as follows: +# From P Chan (2018-05-07): +# The start and end time of DST in China [from 1986 on] should be 2:00 +# (i.e. 2:00 to 3:00 at the start and 2:00 to 1:00 at the end).... +# Government notices about summer time: +# +# 1986-04-12 http://www.zj.gov.cn/attach/zfgb/198608.pdf p.21-22 +# (To establish summer time from 1986. On 4 May, set the clocks ahead one hour +# at 2 am. On 14 September, set the clocks backward one hour at 2 am.) +# +# 1987-02-15 http://www.gov.cn/gongbao/shuju/1987/gwyb198703.pdf p.114 +# (Summer time in 1987 to start from 12 April until 13 September) +# +# 1987-09-09 http://www.gov.cn/gongbao/shuju/1987/gwyb198721.pdf p.709 +# (From 1988, summer time to start from 2 am of the first Sunday of mid-April +# until 2 am of the first Sunday of mid-September) +# +# 1992-03-03 http://www.gov.cn/gongbao/shuju/1992/gwyb199205.pdf p.152 +# (To suspend summer time from 1992) +# +# The first page of People's Daily on 12 April 1988 stating that summer time +# to begin on 17 April. +# http://data.people.com.cn/pic/101p/1988/04/1988041201.jpg + # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S -Rule Shang 1940 only - Jun 3 0:00 1:00 D -Rule Shang 1940 1941 - Oct 1 0:00 0 S -Rule Shang 1941 only - Mar 16 0:00 1:00 D -Rule PRC 1986 only - May 4 0:00 1:00 D -Rule PRC 1986 1991 - Sep Sun>=11 0:00 0 S -Rule PRC 1987 1991 - Apr Sun>=10 0:00 1:00 D +Rule PRC 1986 only - May 4 2:00 1:00 D +Rule PRC 1986 1991 - Sep Sun>=11 2:00 0 S +Rule PRC 1987 1991 - Apr Sun>=11 2:00 1:00 D # From Anthony Fok (2001-12-20): # BTW, I did some research on-line and found some info regarding these five @@ -340,10 +383,11 @@ Rule PRC 1987 1991 - Apr Sun>=10 0:00 1:00 D # Alois Treindl kindly sent me translations of the following two sources: # # (1) -# Guo Qingsheng (National Time-Service Center, CAS, Xi'an 710600, China) +# Guo Qing-sheng (National Time-Service Center, CAS, Xi'an 710600, China) # Beijing Time at the Beginning of the PRC # China Historical Materials of Science and Technology -# (Zhongguo ke ji shi liao, 中国科技史料), Vol. 24, No. 1 (2003) +# (Zhongguo ke ji shi liao, 中国科技史料). 2003;24(1):5-9. +# http://oversea.cnki.net/kcms/detail/detail.aspx?filename=ZGKS200301000&dbname=CJFD2003 # It gives evidence that at the beginning of the PRC, Beijing time was # officially apparent solar time! However, Guo also says that the # evidence is dubious, as the relevant institute of astronomy had not @@ -520,7 +564,7 @@ Rule PRC 1987 1991 - Apr Sun>=10 0:00 1:00 D # Zone NAME GMTOFF RULES FORMAT [UNTIL] # Beijing time, used throughout China; represented by Shanghai. Zone Asia/Shanghai 8:05:43 - LMT 1901 - 8:00 Shang C%sT 1949 + 8:00 Shang C%sT 1949 May 28 8:00 PRC C%sT # Xinjiang time, used by many in western China; represented by Ürümqi / Ürümchi # / Wulumuqi. (Please use Asia/Shanghai if you prefer Beijing time.) @@ -749,23 +793,140 @@ Zone Asia/Taipei 8:06:00 - LMT 1896 Jan 1 8:00 Taiwan C%sT # Macau (Macao, Aomen) +# +# From P Chan (2018-05-10): +# * LegisMac +# http://legismac.safp.gov.mo/legismac/descqry/Descqry.jsf?lang=pt +# A database for searching titles of legal documents of Macau in +# Chinese and Portuguese. The term "HORÁRIO DE VERÃO" can be used for +# searching decrees about summer time. +# * Archives of Macao +# http://www.archives.gov.mo/en/bo/ +# It contains images of old official gazettes. +# * The Macao Meteorological and Geophysical Bureau have a page listing the +# summer time history. But it is not complete and has some mistakes. +# http://www.smg.gov.mo/smg/geophysics/e_t_Summer%20Time.htm +# Macau adopted GMT+8 on 30 Oct 1904 to follow Hong Kong. Clocks were +# advanced by 25 minutes and 50 seconds. Which means the LMT used was +# +7:34:10. As stated in the "Portaria No. 204" dated 21 October 1904 +# and published in the Official Gazette on 29 October 1904. +# http://igallery.icm.gov.mo/Images/Archives/BO/MO_AH_PUB_BO_1904_10/MO_AH_PUB_BO_1904_10_00025_Grey.JPG +# +# Therefore the 1911 decree of Portugal did not change time in Macau. +# +# From LegisMac, here is a list of decrees that changed the time ... +# [Decree Gazette-no. date; titles omitted in this quotation] +# DIL 732 BOCM 51 1941.12.20 +# DIL 764 BOCM 9S 1942.04.30 +# DIL 781 BOCM 21 1942.10.10 +# PT 3434 BOCM 8S 1943.04.17 +# PT 3504 BOCM 20 1943.09.25 +# PT 3843 BOCM 39 1945.09.29 +# PT 3961 BOCM 17 1946.04.27 +# PT 4026 BOCM 39 1946.09.28 +# PT 4153 BOCM 16 1947.04.10 +# PT 4271 BOCM 48 1947.11.29 +# PT 4374 BOCM 18 1948.05.01 +# PT 4465 BOCM 44 1948.10.30 +# PT 4590 BOCM 14 1949.04.02 +# PT 4666 BOCM 44 1949.10.29 +# PT 4771 BOCM 12 1950.03.25 +# PT 4838 BOCM 43 1950.10.28 +# PT 4946 BOCM 12 1951.03.24 +# PT 5025 BO 43 1951.10.27 +# PT 5149 BO 14 1952.04.05 +# PT 5251 BO 43 1952.10.25 +# PT 5366 BO 13 1953.03.28 +# PT 5444 BO 44 1953.10.31 +# PT 5540 BO 12 1954.03.20 +# PT 5589 BO 44 1954.10.30 +# PT 5676 BO 12 1955.03.19 +# PT 5739 BO 45 1955.11.05 +# PT 5823 BO 11 1956.03.17 +# PT 5891 BO 44 1956.11.03 +# PT 5981 BO 12 1957.03.23 +# PT 6064 BO 43 1957.10.26 +# PT 6172 BO 12 1958.03.22 +# PT 6243 BO 43 1958.10.25 +# PT 6341 BO 12 1959.03.21 +# PT 6411 BO 43 1959.10.24 +# PT 6514 BO 11 1960.03.12 +# PT 6584 BO 44 1960.10.29 +# PT 6721 BO 10 1961.03.11 +# PT 6815 BO 43 1961.10.28 +# PT 6947 BO 10 1962.03.10 +# PT 7080 BO 43 1962.10.27 +# PT 7218 BO 12 1963.03.23 +# PT 7340 BO 43 1963.10.26 +# PT 7491 BO 11 1964.03.14 +# PT 7664 BO 43 1964.10.24 +# PT 7846 BO 15 1965.04.10 +# PT 7979 BO 42 1965.10.16 +# PT 8146 BO 15 1966.04.09 +# PT 8252 BO 41 1966.10.08 +# PT 8429 BO 15 1967.04.15 +# PT 8540 BO 41 1967.10.14 +# PT 8735 BO 15 1968.04.13 +# PT 8860 BO 41 1968.10.12 +# PT 9035 BO 16 1969.04.19 +# PT 9156 BO 42 1969.10.18 +# PT 9328 BO 15 1970.04.11 +# PT 9418 BO 41 1970.10.10 +# PT 9587 BO 14 1971.04.03 +# PT 9702 BO 41 1971.10.09 +# PT 38-A/72 BO 14 1972.04.01 +# PT 126-A/72 BO 41 1972.10.07 +# PT 61/73 BO 14 1973.04.07 +# PT 182/73 BO 40 1973.10.06 +# PT 282/73 BO 51 1973.12.22 +# PT 177/74 BO 41 1974.10.12 +# PT 51/75 BO 15 1975.04.12 +# PT 173/75 BO 41 1975.10.11 +# PT 67/76/M BO 14 1976.04.03 +# PT 169/76/M BO 41 1976.10.09 +# PT 78/79/M BO 19 1979.05.12 +# PT 166/79/M BO 42 1979.10.20 +# Note that DIL 732 does not belong to "HORÁRIO DE VERÃO" according to +# LegisMac.... Note that between 1942 and 1945, the time switched +# between GMT+9 and GMT+10. Also in 1965 and 1965 the DST ended at 2:30am. + +# From Paul Eggert (2018-05-10): +# The 1904 decree says that Macau changed from the meridian of +# Fortaleza do Monte, presumably the basis for the 7:34:10 for LMT. + # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S -Rule Macau 1961 1962 - Mar Sun>=16 3:30 1:00 D -Rule Macau 1961 1964 - Nov Sun>=1 3:30 0 S -Rule Macau 1963 only - Mar Sun>=16 0:00 1:00 D -Rule Macau 1964 only - Mar Sun>=16 3:30 1:00 D -Rule Macau 1965 only - Mar Sun>=16 0:00 1:00 D -Rule Macau 1965 only - Oct 31 0:00 0 S -Rule Macau 1966 1971 - Apr Sun>=16 3:30 1:00 D -Rule Macau 1966 1971 - Oct Sun>=16 3:30 0 S -Rule Macau 1972 1974 - Apr Sun>=15 0:00 1:00 D -Rule Macau 1972 1973 - Oct Sun>=15 0:00 0 S -Rule Macau 1974 1977 - Oct Sun>=15 3:30 0 S -Rule Macau 1975 1977 - Apr Sun>=15 3:30 1:00 D -Rule Macau 1978 1980 - Apr Sun>=15 0:00 1:00 D -Rule Macau 1978 1980 - Oct Sun>=15 0:00 0 S +Rule Macau 1942 1943 - Apr 30 23:00 1:00 - +Rule Macau 1942 only - Nov 17 23:00 0 - +Rule Macau 1943 only - Sep 30 23:00 0 S +Rule Macau 1946 only - Apr 30 23:00s 1:00 D +Rule Macau 1946 only - Sep 30 23:00s 0 S +Rule Macau 1947 only - Apr 19 23:00s 1:00 D +Rule Macau 1947 only - Nov 30 23:00s 0 S +Rule Macau 1948 only - May 2 23:00s 1:00 D +Rule Macau 1948 only - Oct 31 23:00s 0 S +Rule Macau 1949 1950 - Apr Sat>=1 23:00s 1:00 D +Rule Macau 1949 1950 - Oct lastSat 23:00s 0 S +Rule Macau 1951 only - Mar 31 23:00s 1:00 D +Rule Macau 1951 only - Oct 28 23:00s 0 S +Rule Macau 1952 1953 - Apr Sat>=1 23:00s 1:00 D +Rule Macau 1952 only - Nov 1 23:00s 0 S +Rule Macau 1953 1954 - Oct lastSat 23:00s 0 S +Rule Macau 1954 1956 - Mar Sat>=17 23:00s 1:00 D +Rule Macau 1955 only - Nov 5 23:00s 0 S +Rule Macau 1956 1964 - Nov Sun>=1 03:30 0 S +Rule Macau 1957 1964 - Mar Sun>=18 03:30 1:00 D +Rule Macau 1965 1973 - Apr Sun>=16 03:30 1:00 D +Rule Macau 1965 1966 - Oct Sun>=16 02:30 0 S +Rule Macau 1967 1976 - Oct Sun>=16 03:30 0 S +Rule Macau 1973 only - Dec 30 03:30 1:00 D +Rule Macau 1975 1976 - Apr Sun>=16 03:30 1:00 D +Rule Macau 1979 only - May 13 03:30 1:00 D +Rule Macau 1979 only - Oct Sun>=16 03:30 0 S + # Zone NAME GMTOFF RULES FORMAT [UNTIL] -Zone Asia/Macau 7:34:20 - LMT 1912 Jan 1 +Zone Asia/Macau 7:34:10 - LMT 1904 Oct 30 + 8:00 - CST 1941 Dec 21 23:00 + 9:00 Macau +09/+10 1945 Sep 30 24:00 8:00 Macau C%sT @@ -1106,61 +1267,61 @@ Zone Asia/Jayapura 9:22:48 - LMT 1932 Nov # thirtieth day of Shahrivar. # # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S -Rule Iran 1978 1980 - Mar 21 0:00 1:00 D -Rule Iran 1978 only - Oct 21 0:00 0 S -Rule Iran 1979 only - Sep 19 0:00 0 S -Rule Iran 1980 only - Sep 23 0:00 0 S -Rule Iran 1991 only - May 3 0:00 1:00 D -Rule Iran 1992 1995 - Mar 22 0:00 1:00 D -Rule Iran 1991 1995 - Sep 22 0:00 0 S -Rule Iran 1996 only - Mar 21 0:00 1:00 D -Rule Iran 1996 only - Sep 21 0:00 0 S -Rule Iran 1997 1999 - Mar 22 0:00 1:00 D -Rule Iran 1997 1999 - Sep 22 0:00 0 S -Rule Iran 2000 only - Mar 21 0:00 1:00 D -Rule Iran 2000 only - Sep 21 0:00 0 S -Rule Iran 2001 2003 - Mar 22 0:00 1:00 D -Rule Iran 2001 2003 - Sep 22 0:00 0 S -Rule Iran 2004 only - Mar 21 0:00 1:00 D -Rule Iran 2004 only - Sep 21 0:00 0 S -Rule Iran 2005 only - Mar 22 0:00 1:00 D -Rule Iran 2005 only - Sep 22 0:00 0 S -Rule Iran 2008 only - Mar 21 0:00 1:00 D -Rule Iran 2008 only - Sep 21 0:00 0 S -Rule Iran 2009 2011 - Mar 22 0:00 1:00 D -Rule Iran 2009 2011 - Sep 22 0:00 0 S -Rule Iran 2012 only - Mar 21 0:00 1:00 D -Rule Iran 2012 only - Sep 21 0:00 0 S -Rule Iran 2013 2015 - Mar 22 0:00 1:00 D -Rule Iran 2013 2015 - Sep 22 0:00 0 S -Rule Iran 2016 only - Mar 21 0:00 1:00 D -Rule Iran 2016 only - Sep 21 0:00 0 S -Rule Iran 2017 2019 - Mar 22 0:00 1:00 D -Rule Iran 2017 2019 - Sep 22 0:00 0 S -Rule Iran 2020 only - Mar 21 0:00 1:00 D -Rule Iran 2020 only - Sep 21 0:00 0 S -Rule Iran 2021 2023 - Mar 22 0:00 1:00 D -Rule Iran 2021 2023 - Sep 22 0:00 0 S -Rule Iran 2024 only - Mar 21 0:00 1:00 D -Rule Iran 2024 only - Sep 21 0:00 0 S -Rule Iran 2025 2027 - Mar 22 0:00 1:00 D -Rule Iran 2025 2027 - Sep 22 0:00 0 S -Rule Iran 2028 2029 - Mar 21 0:00 1:00 D -Rule Iran 2028 2029 - Sep 21 0:00 0 S -Rule Iran 2030 2031 - Mar 22 0:00 1:00 D -Rule Iran 2030 2031 - Sep 22 0:00 0 S -Rule Iran 2032 2033 - Mar 21 0:00 1:00 D -Rule Iran 2032 2033 - Sep 21 0:00 0 S -Rule Iran 2034 2035 - Mar 22 0:00 1:00 D -Rule Iran 2034 2035 - Sep 22 0:00 0 S +Rule Iran 1978 1980 - Mar 21 0:00 1:00 - +Rule Iran 1978 only - Oct 21 0:00 0 - +Rule Iran 1979 only - Sep 19 0:00 0 - +Rule Iran 1980 only - Sep 23 0:00 0 - +Rule Iran 1991 only - May 3 0:00 1:00 - +Rule Iran 1992 1995 - Mar 22 0:00 1:00 - +Rule Iran 1991 1995 - Sep 22 0:00 0 - +Rule Iran 1996 only - Mar 21 0:00 1:00 - +Rule Iran 1996 only - Sep 21 0:00 0 - +Rule Iran 1997 1999 - Mar 22 0:00 1:00 - +Rule Iran 1997 1999 - Sep 22 0:00 0 - +Rule Iran 2000 only - Mar 21 0:00 1:00 - +Rule Iran 2000 only - Sep 21 0:00 0 - +Rule Iran 2001 2003 - Mar 22 0:00 1:00 - +Rule Iran 2001 2003 - Sep 22 0:00 0 - +Rule Iran 2004 only - Mar 21 0:00 1:00 - +Rule Iran 2004 only - Sep 21 0:00 0 - +Rule Iran 2005 only - Mar 22 0:00 1:00 - +Rule Iran 2005 only - Sep 22 0:00 0 - +Rule Iran 2008 only - Mar 21 0:00 1:00 - +Rule Iran 2008 only - Sep 21 0:00 0 - +Rule Iran 2009 2011 - Mar 22 0:00 1:00 - +Rule Iran 2009 2011 - Sep 22 0:00 0 - +Rule Iran 2012 only - Mar 21 0:00 1:00 - +Rule Iran 2012 only - Sep 21 0:00 0 - +Rule Iran 2013 2015 - Mar 22 0:00 1:00 - +Rule Iran 2013 2015 - Sep 22 0:00 0 - +Rule Iran 2016 only - Mar 21 0:00 1:00 - +Rule Iran 2016 only - Sep 21 0:00 0 - +Rule Iran 2017 2019 - Mar 22 0:00 1:00 - +Rule Iran 2017 2019 - Sep 22 0:00 0 - +Rule Iran 2020 only - Mar 21 0:00 1:00 - +Rule Iran 2020 only - Sep 21 0:00 0 - +Rule Iran 2021 2023 - Mar 22 0:00 1:00 - +Rule Iran 2021 2023 - Sep 22 0:00 0 - +Rule Iran 2024 only - Mar 21 0:00 1:00 - +Rule Iran 2024 only - Sep 21 0:00 0 - +Rule Iran 2025 2027 - Mar 22 0:00 1:00 - +Rule Iran 2025 2027 - Sep 22 0:00 0 - +Rule Iran 2028 2029 - Mar 21 0:00 1:00 - +Rule Iran 2028 2029 - Sep 21 0:00 0 - +Rule Iran 2030 2031 - Mar 22 0:00 1:00 - +Rule Iran 2030 2031 - Sep 22 0:00 0 - +Rule Iran 2032 2033 - Mar 21 0:00 1:00 - +Rule Iran 2032 2033 - Sep 21 0:00 0 - +Rule Iran 2034 2035 - Mar 22 0:00 1:00 - +Rule Iran 2034 2035 - Sep 22 0:00 0 - # # The following rules are approximations starting in the year 2038. # These are the best post-2037 approximations available, given the # restrictions of a single rule using a Gregorian-based data format. # At some point this table will need to be extended, though quite # possibly Iran will change the rules first. -Rule Iran 2036 max - Mar 21 0:00 1:00 D -Rule Iran 2036 max - Sep 21 0:00 0 S +Rule Iran 2036 max - Mar 21 0:00 1:00 - +Rule Iran 2036 max - Sep 21 0:00 0 - # Zone NAME GMTOFF RULES FORMAT [UNTIL] Zone Asia/Tehran 3:25:44 - LMT 1916 @@ -1196,17 +1357,17 @@ Zone Asia/Tehran 3:25:44 - LMT 1916 # https://www.timeanddate.com/news/time/iraq-dumps-daylight-saving.html # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S -Rule Iraq 1982 only - May 1 0:00 1:00 D -Rule Iraq 1982 1984 - Oct 1 0:00 0 S -Rule Iraq 1983 only - Mar 31 0:00 1:00 D -Rule Iraq 1984 1985 - Apr 1 0:00 1:00 D -Rule Iraq 1985 1990 - Sep lastSun 1:00s 0 S -Rule Iraq 1986 1990 - Mar lastSun 1:00s 1:00 D +Rule Iraq 1982 only - May 1 0:00 1:00 - +Rule Iraq 1982 1984 - Oct 1 0:00 0 - +Rule Iraq 1983 only - Mar 31 0:00 1:00 - +Rule Iraq 1984 1985 - Apr 1 0:00 1:00 - +Rule Iraq 1985 1990 - Sep lastSun 1:00s 0 - +Rule Iraq 1986 1990 - Mar lastSun 1:00s 1:00 - # IATA SSIM (1991/1996) says Apr 1 12:01am UTC; guess the ':01' is a typo. # Shanks & Pottenger say Iraq did not observe DST 1992/1997; ignore this. # -Rule Iraq 1991 2007 - Apr 1 3:00s 1:00 D -Rule Iraq 1991 2007 - Oct 1 3:00s 0 S +Rule Iraq 1991 2007 - Apr 1 3:00s 1:00 - +Rule Iraq 1991 2007 - Oct 1 3:00s 0 - # Zone NAME GMTOFF RULES FORMAT [UNTIL] Zone Asia/Baghdad 2:57:40 - LMT 1890 2:57:36 - BMT 1918 # Baghdad Mean Time? @@ -1470,16 +1631,35 @@ Zone Asia/Jerusalem 2:20:54 - LMT 1880 # http://www.shugiin.go.jp/internet/itdb_housei.nsf/html/houritsu/00719500331039.htm # ... In summary, it is written as follows. From 24:00 on the first Saturday # in May, until 0:00 on the day after the second Saturday in September. + +# From Phake Nick (2018-09-27): +# [T]he webpage authored by National Astronomical Observatory of Japan +# https://eco.mtk.nao.ac.jp/koyomi/wiki/BBFEB9EF2FB2C6BBFEB9EF.html +# ... mentioned that using Showa 23 (year 1948) as example, 13pm of September +# 11 in summer time will equal to 0am of September 12 in standard time. +# It cited a document issued by the Liaison Office which briefly existed +# during the postwar period of Japan, where the detail on implementation +# of the summer time is described in the document. +# https://eco.mtk.nao.ac.jp/koyomi/wiki/BBFEB9EF2FB2C6BBFEB9EFB2C6BBFEB9EFA4CEBCC2BBDCA4CBA4C4A4A4A4C6.pdf +# The text in the document do instruct a fall back to occur at +# September 11, 13pm in summer time, while ordinary citizens can +# change the clock before they sleep. +# +# From Paul Eggert (2018-09-27): +# This instruction is equivalent to "Sat>=8 25:00", so use that. zic treats +# it like "Sun>=9 01:00", which is not quite the same but is the best we can +# do in any POSIX or C platform. The "25:00" assumes zic from 2007 or later, +# which should be safe now. + # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S Rule Japan 1948 only - May Sat>=1 24:00 1:00 D -Rule Japan 1948 1951 - Sep Sun>=9 0:00 0 S +Rule Japan 1948 1951 - Sep Sat>=8 25:00 0 S Rule Japan 1949 only - Apr Sat>=1 24:00 1:00 D Rule Japan 1950 1951 - May Sat>=1 24:00 1:00 D # From Hideyuki Suzuki (1998-11-09): # 'Tokyo' usually stands for the former location of Tokyo Astronomical -# Observatory: 139 degrees 44' 40.90" E (9h 18m 58.727s), -# 35 degrees 39' 16.0" N. +# Observatory: 139° 44' 40.90" E (9h 18m 58.727s), 35° 39' 16.0" N. # This data is from 'Rika Nenpyou (Chronological Scientific Tables) 1996' # edited by National Astronomical Observatory of Japan.... # JST (Japan Standard Time) has been used since 1888-01-01 00:00 (JST). @@ -1487,10 +1667,10 @@ Rule Japan 1950 1951 - May Sat>=1 24:00 1:00 D # From Hideyuki Suzuki (1998-11-16): # The ordinance No. 51 (1886) established "standard time" in Japan, -# which stands for the time on 135 degrees E. +# which stands for the time on 135° E. # In the ordinance No. 167 (1895), "standard time" was renamed to "central # standard time". And the same ordinance also established "western standard -# time", which stands for the time on 120 degrees E.... But "western standard +# time", which stands for the time on 120° E.... But "western standard # time" was abolished in the ordinance No. 529 (1937). In the ordinance No. # 167, there is no mention regarding for what place western standard time is # standard.... @@ -1855,7 +2035,7 @@ Zone Asia/Aqtobe 3:48:40 - LMT 1924 May 2 5:00 - +05 # Mangghystaū (KZ-MAN) # Aqtau was not founded until 1963, but it represents an inhabited region, -# so include time stamps before 1963. +# so include timestamps before 1963. Zone Asia/Aqtau 3:21:04 - LMT 1924 May 2 4:00 - +04 1930 Jun 21 5:00 - +05 1981 Oct 1 @@ -1903,9 +2083,9 @@ Zone Asia/Oral 3:25:24 - LMT 1924 May 2 # or Ural'sk # From 2005-08-12 our GMT-offset is +6, w/o any daylight saving. # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S -Rule Kyrgyz 1992 1996 - Apr Sun>=7 0:00s 1:00 S +Rule Kyrgyz 1992 1996 - Apr Sun>=7 0:00s 1:00 - Rule Kyrgyz 1992 1996 - Sep lastSun 0:00 0 - -Rule Kyrgyz 1997 2005 - Mar lastSun 2:30 1:00 S +Rule Kyrgyz 1997 2005 - Mar lastSun 2:30 1:00 - Rule Kyrgyz 1997 2004 - Oct lastSun 2:30 0 - # Zone NAME GMTOFF RULES FORMAT [UNTIL] Zone Asia/Bishkek 4:58:24 - LMT 1924 May 2 @@ -1983,6 +2163,23 @@ Rule ROK 1987 1988 - Oct Sun>=8 3:00 0 S # There is no common English-language abbreviation for this time zone. # Use KST, as that's what we already use for 1954-1961 in ROK. +# From Kang Seonghoon (2018-04-29): +# North Korea will revert its time zone from UTC+8:30 (PYT; Pyongyang +# Time) back to UTC+9 (KST; Korea Standard Time). +# +# From Seo Sanghyeon (2018-04-30): +# Rodong Sinmun 2018-04-30 announced Pyongyang Time transition plan. +# https://www.nknews.org/kcna/wp-content/uploads/sites/5/2018/04/rodong-2018-04-30.pdf +# ... the transition date is 2018-05-05 ... Citation should be Decree +# No. 2232 of April 30, 2018, of the Presidium of the Supreme People's +# Assembly, as published in Rodong Sinmun. +# From Tim Parenti (2018-04-29): +# It appears to be the front page story at the top in the right-most column. +# +# From Paul Eggert (2018-05-04): +# The BBC reported that the transition was from 23:30 to 24:00 today. +# https://www.bbc.com/news/world-asia-44010705 + # Zone NAME GMTOFF RULES FORMAT [UNTIL] Zone Asia/Seoul 8:27:52 - LMT 1908 Apr 1 8:30 - KST 1912 Jan 1 @@ -1994,7 +2191,8 @@ Zone Asia/Pyongyang 8:23:00 - LMT 1908 Apr 1 8:30 - KST 1912 Jan 1 9:00 - JST 1945 Aug 24 9:00 - KST 2015 Aug 15 00:00 - 8:30 - KST + 8:30 - KST 2018 May 4 23:30 + 9:00 - KST ############################################################################### @@ -2037,7 +2235,7 @@ Zone Asia/Beirut 2:22:00 - LMT 1880 # Malaysia # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S -Rule NBorneo 1935 1941 - Sep 14 0:00 0:20 TS # one-Third Summer +Rule NBorneo 1935 1941 - Sep 14 0:00 0:20 - Rule NBorneo 1935 1941 - Dec 14 0:00 0 - # # peninsular Malaysia @@ -2182,7 +2380,7 @@ Zone Indian/Maldives 4:54:00 - LMT 1880 # Malé # http://zasag.mn/news/view/8969 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S -Rule Mongol 1983 1984 - Apr 1 0:00 1:00 S +Rule Mongol 1983 1984 - Apr 1 0:00 1:00 - Rule Mongol 1983 only - Oct 1 0:00 0 - # Shanks & Pottenger and IATA SSIM say 1990s switches occurred at 00:00, # but McDow says the 2001 switches occurred at 02:00. Also, IATA SSIM @@ -2199,13 +2397,13 @@ Rule Mongol 1983 only - Oct 1 0:00 0 - # Mongolian Government meeting has concluded today to cancel daylight # saving time adoption in Mongolia. Source: http://zasag.mn/news/view/16192 -Rule Mongol 1985 1998 - Mar lastSun 0:00 1:00 S +Rule Mongol 1985 1998 - Mar lastSun 0:00 1:00 - Rule Mongol 1984 1998 - Sep lastSun 0:00 0 - # IATA SSIM (1999-09) says Mongolia no longer observes DST. -Rule Mongol 2001 only - Apr lastSat 2:00 1:00 S +Rule Mongol 2001 only - Apr lastSat 2:00 1:00 - Rule Mongol 2001 2006 - Sep lastSat 2:00 0 - -Rule Mongol 2002 2006 - Mar lastSat 2:00 1:00 S -Rule Mongol 2015 2016 - Mar lastSat 2:00 1:00 S +Rule Mongol 2002 2006 - Mar lastSat 2:00 1:00 - +Rule Mongol 2015 2016 - Mar lastSat 2:00 1:00 - Rule Mongol 2015 2016 - Sep lastSat 0:00 0 - # Zone NAME GMTOFF RULES FORMAT [UNTIL] @@ -2639,9 +2837,6 @@ Zone Asia/Karachi 4:28:12 - LMT 1907 # [Google translation]: "The Council also decided to start daylight # saving in Palestine as of one o'clock on Saturday morning, # 2016-03-26, to provide the clock 60 minutes ahead." -# -# From Paul Eggert (2016-03-12): -# Predict spring transitions on March's last Saturday at 01:00 from now on. # From Sharef Mustafa (2016-10-19): # [T]he Palestinian cabinet decision (Mar 8th 2016) published on @@ -2658,6 +2853,16 @@ Zone Asia/Karachi 4:28:12 - LMT 1907 # https://www.timeanddate.com/time/change/gaza-strip/gaza # https://www.timeanddate.com/time/change/west-bank/hebron +# From Sharef Mustafa (2018-03-16): +# Palestine summer time will start on Mar 24th 2018 by advancing the +# clock by 60 minutes as per Palestinian cabinet decision published on +# the official website, though the decree did not specify the exact +# time of the time shift. +# http://www.palestinecabinet.gov.ps/Website/AR/NDecrees/ViewFile.ashx?ID=e7a42ab7-ee23-435a-b9c8-a4f7e81f3817 +# +# From Paul Eggert (2018-03-16): +# For 2016 on, predict spring transitions on March's fourth Saturday at 01:00. + # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S Rule EgyptAsia 1957 only - May 10 0:00 1:00 S Rule EgyptAsia 1957 1958 - Oct 1 0:00 0 - @@ -2687,7 +2892,7 @@ Rule Palestine 2012 only - Sep 21 1:00 0 - Rule Palestine 2013 only - Sep Fri>=21 0:00 0 - Rule Palestine 2014 2015 - Oct Fri>=21 0:00 0 - Rule Palestine 2015 only - Mar lastFri 24:00 1:00 S -Rule Palestine 2016 max - Mar lastSat 1:00 1:00 S +Rule Palestine 2016 max - Mar Sat>=22 1:00 1:00 S Rule Palestine 2016 max - Oct lastSat 1:00 0 - # Zone NAME GMTOFF RULES FORMAT [UNTIL] @@ -2736,19 +2941,35 @@ Zone Asia/Hebron 2:20:23 - LMT 1900 Oct # Philippine Star 2014-08-05 # http://www.philstar.com/headlines/2014/08/05/1354152/pnoy-urged-declare-use-daylight-saving-time +# From Paul Goyette (2018-06-15): +# In the Philippines, there is a national law, Republic Act No. 10535 +# which declares the official time here as "Philippine Standard Time". +# The act [1] even specifies use of PST as the abbreviation, although +# the FAQ provided by PAGASA [2] uses the "acronym PhST to distinguish +# it from the Pacific Standard Time (PST)." +# [1] http://www.officialgazette.gov.ph/2013/05/15/republic-act-no-10535/ +# [2] https://www1.pagasa.dost.gov.ph/index.php/astronomy/philippine-standard-time#republic-act-10535 +# +# From Paul Eggert (2018-06-19): +# I surveyed recent news reports, and my impression is that "PST" is +# more popular among reliable English-language news sources. This is +# not just a measure of Google hit counts: it's also the sizes and +# influence of the sources. There is no current abbreviation for DST, +# so use "PDT", the usual American style. + # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S -Rule Phil 1936 only - Nov 1 0:00 1:00 S -Rule Phil 1937 only - Feb 1 0:00 0 - -Rule Phil 1954 only - Apr 12 0:00 1:00 S -Rule Phil 1954 only - Jul 1 0:00 0 - -Rule Phil 1978 only - Mar 22 0:00 1:00 S -Rule Phil 1978 only - Sep 21 0:00 0 - +Rule Phil 1936 only - Nov 1 0:00 1:00 D +Rule Phil 1937 only - Feb 1 0:00 0 S +Rule Phil 1954 only - Apr 12 0:00 1:00 D +Rule Phil 1954 only - Jul 1 0:00 0 S +Rule Phil 1978 only - Mar 22 0:00 1:00 D +Rule Phil 1978 only - Sep 21 0:00 0 S # Zone NAME GMTOFF RULES FORMAT [UNTIL] Zone Asia/Manila -15:56:00 - LMT 1844 Dec 31 8:04:00 - LMT 1899 May 11 - 8:00 Phil +08/+09 1942 May - 9:00 - +09 1944 Nov - 8:00 Phil +08/+09 + 8:00 Phil P%sT 1942 May + 9:00 - JST 1944 Nov + 8:00 Phil P%sT # Qatar # Zone NAME GMTOFF RULES FORMAT [UNTIL] @@ -2759,15 +2980,34 @@ Link Asia/Qatar Asia/Bahrain # Saudi Arabia # -# From Paul Eggert (2014-07-15): +# From Paul Eggert (2018-08-29): # Time in Saudi Arabia and other countries in the Arabian peninsula was not -# standardized until relatively recently; we don't know when, and possibly it +# standardized until 1968 or so; we don't know exactly when, and possibly it # has never been made official. Richard P Hunt, in "Islam city yielding to # modern times", New York Times (1961-04-09), p 20, wrote that only airlines # observed standard time, and that people in Jeddah mostly observed quasi-solar # time, doing so by setting their watches at sunrise to 6 o'clock (or to 12 # o'clock for "Arab" time). # +# Timekeeping differed depending on who you were and which part of Saudi +# Arabia you were in. In 1969, Elias Antar wrote that although a common +# practice had been to set one's watch to 12:00 (i.e., midnight) at sunset - +# which meant that the time on one side of a mountain could differ greatly from +# the time on the other side - many foreigners set their watches to 6pm +# instead, while airlines instead used UTC +03 (except in Dhahran, where they +# used UTC +04), Aramco used UTC +03 with DST, and the Trans-Arabian Pipe Line +# Company used Aramco time in eastern Saudi Arabia and airline time in western. +# (The American Military Aid Advisory Group used plain UTC.) Antar writes, +# "A man named Higgins, so the story goes, used to run a local power +# station. One day, the whole thing became too much for Higgins and he +# assembled his staff and laid down the law. 'I've had enough of this,' he +# shrieked. 'It is now 12 o'clock Higgins Time, and from now on this station is +# going to run on Higgins Time.' And so, until last year, it did." See: +# Antar E. Dinner at When? Saudi Aramco World, 1969 March/April. 2-3. +# http://archive.aramcoworld.com/issue/196902/dinner.at.when.htm +# newspapers.com says a similar story about Higgins was published in the Port +# Angeles (WA) Evening News, 1965-03-10, page 5, but I lack access to the text. +# # The TZ database cannot represent quasi-solar time; airline time is the best # we can do. The 1946 foreign air news digest of the U.S. Civil Aeronautics # Board (OCLC 42299995) reported that the "... Arabian Government, inaugurated @@ -2777,7 +3017,8 @@ Link Asia/Qatar Asia/Bahrain # # Shanks & Pottenger also state that until 1968-05-01 Saudi Arabia had two # time zones; the other zone, at UT +04, was in the far eastern part of -# the country. Ignore this, as it's before our 1970 cutoff. +# the country. Presumably this is documenting airline time. Ignore this, +# as it's before our 1970 cutoff. # # Zone NAME GMTOFF RULES FORMAT [UNTIL] Zone Asia/Riyadh 3:06:52 - LMT 1947 Mar 14 @@ -3097,9 +3338,9 @@ Zone Asia/Tashkent 4:37:11 - LMT 1924 May 2 # and is the basis for the information below. # # The 1906 transition was effective July 1 and standardized Indochina to -# Phù Liễn Observatory, legally 104 deg. 17'17" east of Paris. +# Phù Liễn Observatory, legally 104° 17' 17" east of Paris. # It's unclear whether this meant legal Paris Mean Time (00:09:21) or -# the Paris Meridian (2 deg. 20'14.03" E); the former yields 07:06:30.1333... +# the Paris Meridian (2° 20' 14.03" E); the former yields 07:06:30.1333... # and the latter 07:06:29.333... so either way it rounds to 07:06:30, # which is used below even though the modern-day Phù Liễn Observatory # is closer to 07:06:31. Abbreviate Phù Liễn Mean Time as PLMT. diff --git a/contrib/tzdata/australasia b/contrib/tzdata/australasia index b4ef16817c..87ba620d9f 100644 --- a/contrib/tzdata/australasia +++ b/contrib/tzdata/australasia @@ -1,3 +1,5 @@ +# tzdb data for Australasia and environs, and for much of the Pacific + # This file is in the public domain, so clarified as of # 2009-05-17 by Arthur David Olson. @@ -196,20 +198,20 @@ Zone Australia/Broken_Hill 9:25:48 - LMT 1895 Feb # Lord Howe Island # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S -Rule LH 1981 1984 - Oct lastSun 2:00 1:00 D -Rule LH 1982 1985 - Mar Sun>=1 2:00 0 S -Rule LH 1985 only - Oct lastSun 2:00 0:30 D -Rule LH 1986 1989 - Mar Sun>=15 2:00 0 S -Rule LH 1986 only - Oct 19 2:00 0:30 D -Rule LH 1987 1999 - Oct lastSun 2:00 0:30 D -Rule LH 1990 1995 - Mar Sun>=1 2:00 0 S -Rule LH 1996 2005 - Mar lastSun 2:00 0 S -Rule LH 2000 only - Aug lastSun 2:00 0:30 D -Rule LH 2001 2007 - Oct lastSun 2:00 0:30 D -Rule LH 2006 only - Apr Sun>=1 2:00 0 S -Rule LH 2007 only - Mar lastSun 2:00 0 S -Rule LH 2008 max - Apr Sun>=1 2:00 0 S -Rule LH 2008 max - Oct Sun>=1 2:00 0:30 D +Rule LH 1981 1984 - Oct lastSun 2:00 1:00 - +Rule LH 1982 1985 - Mar Sun>=1 2:00 0 - +Rule LH 1985 only - Oct lastSun 2:00 0:30 - +Rule LH 1986 1989 - Mar Sun>=15 2:00 0 - +Rule LH 1986 only - Oct 19 2:00 0:30 - +Rule LH 1987 1999 - Oct lastSun 2:00 0:30 - +Rule LH 1990 1995 - Mar Sun>=1 2:00 0 - +Rule LH 1996 2005 - Mar lastSun 2:00 0 - +Rule LH 2000 only - Aug lastSun 2:00 0:30 - +Rule LH 2001 2007 - Oct lastSun 2:00 0:30 - +Rule LH 2006 only - Apr Sun>=1 2:00 0 - +Rule LH 2007 only - Mar lastSun 2:00 0 - +Rule LH 2008 max - Apr Sun>=1 2:00 0 - +Rule LH 2008 max - Oct Sun>=1 2:00 0:30 - Zone Australia/Lord_Howe 10:36:20 - LMT 1895 Feb 10:00 - AEST 1981 Mar 10:30 LH +1030/+1130 1985 Jul @@ -361,22 +363,29 @@ Zone Indian/Cocos 6:27:40 - LMT 1900 # Dominic Fok writes (2017-08-20) that DST ends 2018-01-14, citing # Extraordinary Government of Fiji Gazette Supplement No. 21 (2017-08-27), # [Legal Notice No. 41] of an order of the previous day by J Usamate. + +# From Raymond Kumar (2018-07-13): +# http://www.fijitimes.com/government-approves-2018-daylight-saving/ +# ... The daylight saving period will end at 3am on Sunday January 13, 2019. +# +# From Paul Eggert (2018-07-15): # For now, guess DST from 02:00 the first Sunday in November to 03:00 -# the first Sunday on or after January 14. Although ad hoc, it matches +# the first Sunday on or after January 13. January transitions reportedly +# depend on when school terms start. Although the guess is ad hoc, it matches # transitions since late 2014 and seems more likely to match future # practice than guessing no DST. # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S -Rule Fiji 1998 1999 - Nov Sun>=1 2:00 1:00 S +Rule Fiji 1998 1999 - Nov Sun>=1 2:00 1:00 - Rule Fiji 1999 2000 - Feb lastSun 3:00 0 - -Rule Fiji 2009 only - Nov 29 2:00 1:00 S +Rule Fiji 2009 only - Nov 29 2:00 1:00 - Rule Fiji 2010 only - Mar lastSun 3:00 0 - -Rule Fiji 2010 2013 - Oct Sun>=21 2:00 1:00 S +Rule Fiji 2010 2013 - Oct Sun>=21 2:00 1:00 - Rule Fiji 2011 only - Mar Sun>=1 3:00 0 - Rule Fiji 2012 2013 - Jan Sun>=18 3:00 0 - Rule Fiji 2014 only - Jan Sun>=18 2:00 0 - -Rule Fiji 2014 max - Nov Sun>=1 2:00 1:00 S -Rule Fiji 2015 max - Jan Sun>=14 3:00 0 - +Rule Fiji 2014 max - Nov Sun>=1 2:00 1:00 - +Rule Fiji 2015 max - Jan Sun>=13 3:00 0 - # Zone NAME GMTOFF RULES FORMAT [UNTIL] Zone Pacific/Fiji 11:55:44 - LMT 1915 Oct 26 # Suva 12:00 Fiji +12/+13 @@ -406,11 +415,11 @@ Zone Pacific/Tarawa 11:32:04 - LMT 1901 # Bairiki 12:00 - +12 Zone Pacific/Enderbury -11:24:20 - LMT 1901 -12:00 - -12 1979 Oct - -11:00 - -11 1995 + -11:00 - -11 1994 Dec 31 13:00 - +13 Zone Pacific/Kiritimati -10:29:20 - LMT 1901 -10:40 - -1040 1979 Oct - -10:00 - -10 1995 + -10:00 - -10 1994 Dec 31 14:00 - +14 # N Mariana Is @@ -447,9 +456,9 @@ Zone Pacific/Nauru 11:07:40 - LMT 1921 Jan 15 # Uaobe # New Caledonia # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S -Rule NC 1977 1978 - Dec Sun>=1 0:00 1:00 S +Rule NC 1977 1978 - Dec Sun>=1 0:00 1:00 - Rule NC 1978 1979 - Feb 27 0:00 0 - -Rule NC 1996 only - Dec 1 2:00s 1:00 S +Rule NC 1996 only - Dec 1 2:00s 1:00 - # Shanks & Pottenger say the following was at 2:00; go with IATA. Rule NC 1997 only - Mar 2 2:00s 0 - # Zone NAME GMTOFF RULES FORMAT [UNTIL] @@ -469,27 +478,28 @@ Rule NZ 1929 1933 - Mar Sun>=15 2:00 0 M Rule NZ 1934 1940 - Apr lastSun 2:00 0 M Rule NZ 1934 1940 - Sep lastSun 2:00 0:30 S Rule NZ 1946 only - Jan 1 0:00 0 S -# Since 1957 Chatham has been 45 minutes ahead of NZ, but there's no -# convenient single notation for the date and time of this transition -# so we must duplicate the Rule lines. +# Since 1957 Chatham has been 45 minutes ahead of NZ, but until 2018a +# there was no documented single notation for the date and time of this +# transition. Duplicate the Rule lines for now, to give the 2018a change +# time to percolate out. Rule NZ 1974 only - Nov Sun>=1 2:00s 1:00 D -Rule Chatham 1974 only - Nov Sun>=1 2:45s 1:00 D +Rule Chatham 1974 only - Nov Sun>=1 2:45s 1:00 - Rule NZ 1975 only - Feb lastSun 2:00s 0 S -Rule Chatham 1975 only - Feb lastSun 2:45s 0 S +Rule Chatham 1975 only - Feb lastSun 2:45s 0 - Rule NZ 1975 1988 - Oct lastSun 2:00s 1:00 D -Rule Chatham 1975 1988 - Oct lastSun 2:45s 1:00 D +Rule Chatham 1975 1988 - Oct lastSun 2:45s 1:00 - Rule NZ 1976 1989 - Mar Sun>=1 2:00s 0 S -Rule Chatham 1976 1989 - Mar Sun>=1 2:45s 0 S +Rule Chatham 1976 1989 - Mar Sun>=1 2:45s 0 - Rule NZ 1989 only - Oct Sun>=8 2:00s 1:00 D -Rule Chatham 1989 only - Oct Sun>=8 2:45s 1:00 D +Rule Chatham 1989 only - Oct Sun>=8 2:45s 1:00 - Rule NZ 1990 2006 - Oct Sun>=1 2:00s 1:00 D -Rule Chatham 1990 2006 - Oct Sun>=1 2:45s 1:00 D +Rule Chatham 1990 2006 - Oct Sun>=1 2:45s 1:00 - Rule NZ 1990 2007 - Mar Sun>=15 2:00s 0 S -Rule Chatham 1990 2007 - Mar Sun>=15 2:45s 0 S +Rule Chatham 1990 2007 - Mar Sun>=15 2:45s 0 - Rule NZ 2007 max - Sep lastSun 2:00s 1:00 D -Rule Chatham 2007 max - Sep lastSun 2:45s 1:00 D +Rule Chatham 2007 max - Sep lastSun 2:45s 1:00 - Rule NZ 2008 max - Apr Sun>=1 2:00s 0 S -Rule Chatham 2008 max - Apr Sun>=1 2:45s 0 S +Rule Chatham 2008 max - Apr Sun>=1 2:45s 0 - # Zone NAME GMTOFF RULES FORMAT [UNTIL] Zone Pacific/Auckland 11:39:04 - LMT 1868 Nov 2 11:30 NZ NZ%sT 1946 Jan 1 @@ -513,9 +523,9 @@ Link Pacific/Auckland Antarctica/McMurdo # Cook Is # From Shanks & Pottenger: # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S -Rule Cook 1978 only - Nov 12 0:00 0:30 HS +Rule Cook 1978 only - Nov 12 0:00 0:30 - Rule Cook 1979 1991 - Mar Sun>=1 0:00 0 - -Rule Cook 1979 1990 - Oct lastSun 0:00 0:30 HS +Rule Cook 1979 1990 - Oct lastSun 0:00 0:30 - # Zone NAME GMTOFF RULES FORMAT [UNTIL] Zone Pacific/Rarotonga -10:39:04 - LMT 1901 # Avarua -10:30 - -1030 1978 Nov 12 @@ -656,11 +666,11 @@ Link Pacific/Pago_Pago Pacific/Midway # in US minor outlying islands # Assume the pattern instituted in 2012 will continue indefinitely. # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S -Rule WS 2010 only - Sep lastSun 0:00 1 D -Rule WS 2011 only - Apr Sat>=1 4:00 0 S -Rule WS 2011 only - Sep lastSat 3:00 1 D -Rule WS 2012 max - Apr Sun>=1 4:00 0 S -Rule WS 2012 max - Sep lastSun 3:00 1 D +Rule WS 2010 only - Sep lastSun 0:00 1 - +Rule WS 2011 only - Apr Sat>=1 4:00 0 - +Rule WS 2011 only - Sep lastSat 3:00 1 - +Rule WS 2012 max - Apr Sun>=1 4:00 0 - +Rule WS 2012 max - Sep lastSun 3:00 1 - # Zone NAME GMTOFF RULES FORMAT [UNTIL] Zone Pacific/Apia 12:33:04 - LMT 1892 Jul 5 -11:26:56 - LMT 1911 @@ -700,11 +710,11 @@ Zone Pacific/Fakaofo -11:24:56 - LMT 1901 # Tonga # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S -Rule Tonga 1999 only - Oct 7 2:00s 1:00 S +Rule Tonga 1999 only - Oct 7 2:00s 1:00 - Rule Tonga 2000 only - Mar 19 2:00s 0 - -Rule Tonga 2000 2001 - Nov Sun>=1 2:00 1:00 S +Rule Tonga 2000 2001 - Nov Sun>=1 2:00 1:00 - Rule Tonga 2001 2002 - Jan lastSun 2:00 0 - -Rule Tonga 2016 only - Nov Sun>=1 2:00 1:00 S +Rule Tonga 2016 only - Nov Sun>=1 2:00 1:00 - Rule Tonga 2017 only - Jan Sun>=15 3:00 0 - # Zone NAME GMTOFF RULES FORMAT [UNTIL] Zone Pacific/Tongatapu 12:19:20 - LMT 1901 @@ -781,12 +791,12 @@ Zone Pacific/Wake 11:06:28 - LMT 1901 # Vanuatu # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S -Rule Vanuatu 1983 only - Sep 25 0:00 1:00 S +Rule Vanuatu 1983 only - Sep 25 0:00 1:00 - Rule Vanuatu 1984 1991 - Mar Sun>=23 0:00 0 - -Rule Vanuatu 1984 only - Oct 23 0:00 1:00 S -Rule Vanuatu 1985 1991 - Sep Sun>=23 0:00 1:00 S +Rule Vanuatu 1984 only - Oct 23 0:00 1:00 - +Rule Vanuatu 1985 1991 - Sep Sun>=23 0:00 1:00 - Rule Vanuatu 1992 1993 - Jan Sun>=23 0:00 0 - -Rule Vanuatu 1992 only - Oct Sun>=23 0:00 1:00 S +Rule Vanuatu 1992 only - Oct Sun>=23 0:00 1:00 - # Zone NAME GMTOFF RULES FORMAT [UNTIL] Zone Pacific/Efate 11:13:16 - LMT 1912 Jan 13 # Vila 11:00 Vanuatu +11/+12 @@ -1084,7 +1094,23 @@ Zone Pacific/Wallis 12:15:20 - LMT 1901 # (1999-09-27) writes that Giles Meteorological Station uses # South Australian time even though it's located in Western Australia. +# From Paul Eggert (2018-04-01): +# The Guardian Express of Perth, Australia reported today that the +# government decided to advance the clocks permanently on January 1, +# 2019, from UT +08 to UT +09. The article noted that an exemption +# would be made for people aged 61 and over, who "can apply in writing +# to have the extra hour of sunshine removed from their area." See: +# Daylight saving coming to WA in 2019. Guardian Express. 2018-04-01. +# https://www.communitynews.com.au/guardian-express/news/exclusive-daylight-savings-coming-wa-summer-2018/ + # Queensland + +# From Paul Eggert (2018-02-26): +# I lack access to the following source for Queensland DST: +# Pearce C. History of daylight saving time in Queensland. +# Queensland Hist J. 2017 Aug;23(6):389-403 +# https://search.informit.com.au/documentSummary;dn=994682348436426;res=IELHSS + # From George Shepherd via Simon Woodhead via Robert Elz (1991-03-06): # # The state of QUEENSLAND.. [ Courtesy Qld. Dept Premier Econ&Trade Devel ] # # [ Dec 1990 ] @@ -1511,6 +1537,12 @@ Zone Pacific/Wallis 12:15:20 - LMT 1901 # "declared it the same day [throughout] the country as of Jan. 1, 1995" # as part of the competition to be first into the 21st century. +# From Kerry Shetline (2018-02-03): +# December 31 was the day that was skipped, so that the transition +# would be from Friday December 30, 1994 to Sunday January 1, 1995. +# From Paul Eggert (2018-02-04): +# One source for this is page 202 of: Bartky IR. One Time Fits All: +# The Campaigns for Global Uniformity (2007). # Kwajalein @@ -1603,7 +1635,7 @@ Zone Pacific/Wallis 12:15:20 - LMT 1901 # From Howie Phelps (1999-11-10), who talked to a Pitcairner via shortwave: # Betty Christian told me yesterday that their local time is the same as -# Pacific Standard Time. They used to be 1/2 hour different from us here in +# Pacific Standard Time. They used to be ½ hour different from us here in # Sacramento but it was changed a couple of years ago. @@ -1642,7 +1674,7 @@ Zone Pacific/Wallis 12:15:20 - LMT 1901 # 12 hours and 20 minutes ahead of GMT. When New Zealand adjusted its # standard time in 1940s, Tonga had the choice of subtracting from its # local time to come on the same standard time as New Zealand or of -# advancing its time to maintain the differential of 13 degrees +# advancing its time to maintain the differential of 13° # (approximately 50 minutes ahead of New Zealand time). # # Because His Majesty King Tāufaʻāhau Tupou IV, then Crown Prince diff --git a/contrib/tzdata/backward b/contrib/tzdata/backward index 2141f0d579..51e10f4ce4 100644 --- a/contrib/tzdata/backward +++ b/contrib/tzdata/backward @@ -1,7 +1,9 @@ +# tzdb links for backward compatibility + # This file is in the public domain, so clarified as of # 2009-05-17 by Arthur David Olson. -# This file provides links between current names for time zones +# This file provides links between current names for timezones # and their old names. Many names changed in late 1993. # Link TARGET LINK-NAME diff --git a/contrib/tzdata/backzone b/contrib/tzdata/backzone index 3006b27f32..97792b1cc8 100644 --- a/contrib/tzdata/backzone +++ b/contrib/tzdata/backzone @@ -16,13 +16,13 @@ # the file 'backward'. # Although zones in this file may be of some use for analyzing -# pre-1970 time stamps, they are less reliable, cover only a tiny +# pre-1970 timestamps, they are less reliable, cover only a tiny # sliver of the pre-1970 era, and cannot feasibly be improved to cover # most of the era. Because the zones are out of normal scope for the # database, less effort is put into maintaining this file. Many of # the zones were formerly in other source files, but were removed or # replaced by links as their data entries were questionable and/or they -# differed from other zones only in pre-1970 time stamps. +# differed from other zones only in pre-1970 timestamps. # Unless otherwise specified, the source for data through 1990 is: # Thomas G. Shanks and Rique Pottenger, The International Atlas (6th edition), @@ -170,13 +170,13 @@ Zone Africa/Lome 0:04:52 - LMT 1893 # Angola # +# From Paul Eggert (2018-02-16): # Shanks gives 1911-05-26 for the transition to WAT, # evidently confusing the date of the Portuguese decree -# https://dre.pt/pdf1sdip/1911/05/12500/23132313.pdf -# with the date that it took effect, namely 1912-01-01. +# (see Europe/Lisbon) with the date that it took effect. # Zone Africa/Luanda 0:52:56 - LMT 1892 - 0:52:04 - LMT 1912 Jan 1 # Luanda Mean Time? + 0:52:04 - LMT 1911 Dec 31 23:00u # Luanda MT? 1:00 - WAT # Democratic Republic of the Congo (east) @@ -271,9 +271,19 @@ Zone America/Aruba -4:40:24 - LMT 1912 Feb 12 # Oranjestad # Cayman Is Zone America/Cayman -5:25:32 - LMT 1890 # Georgetown - -5:07:11 - KMT 1912 Feb # Kingston Mean Time + -5:07:10 - KMT 1912 Feb # Kingston Mean Time -5:00 - EST +# United States +# +# From Paul Eggert (2018-03-18): +# America/Chillicothe would be tricky, as it was a city of two-timers: +# "To prevent a constant mixup at Chillicothe, caused by the courthouse +# clock running on central time and the city running on 'daylight saving' +# time, a third hand was added to the dial of the courthouse clock." +# -- Ohio news in brief. The Cedarville Herald. 1920-05-21;43(21):1 (col. 5) +# https://digitalcommons.cedarville.edu/cedarville_herald/794 + # Canada Zone America/Coral_Harbour -5:32:40 - LMT 1884 -5:00 NT_YK E%sT 1946 @@ -348,6 +358,30 @@ Zone America/Montreal -4:54:16 - LMT 1884 Zone America/Montserrat -4:08:52 - LMT 1911 Jul 1 0:01 # Cork Hill -4:00 - AST +# United States +# +# From Paul Eggert (2018-03-18): +# America/Palm_Springs would be tricky, as it kept two sets of clocks +# in 1946/7. See the following notes. +# +# From Steve Allen (2018-01-19): +# The shadow of Mt. San Jacinto brings darkness very early in the winter +# months. In 1946 the chamber of commerce decided to put the clocks of Palm +# Springs forward by an hour in the winter. +# https://www.desertsun.com/story/life/2017/12/27/palm-springs-struggle-daylight-savings-time-and-idea-sun-time/984416001/ +# Desert Sun, Number 18, 1 November 1946 +# https://cdnc.ucr.edu/cgi-bin/cdnc?a=d&d=DS19461101 +# has proposal for meeting on front page and page 21. +# Desert Sun, Number 19, 5 November 1946 +# https://cdnc.ucr.edu/cgi-bin/cdnc?a=d&d=DS19461105 +# reports that Sun Time won at the meeting on front page and page 5. +# Desert Sun, Number 37, 7 January 1947 +# https://cdnc.ucr.edu/cgi-bin/cdnc?a=d&d=DS19470107.2.12 +# front page reports request to abandon Sun Time and page 7 notes a "class war". +# Desert Sun, Number 38, 10 January 1947 +# https://cdnc.ucr.edu/cgi-bin/cdnc?a=d&d=DS19470110 +# front page reports on end. + # Argentina # This entry was intended for the following areas, but has been superseded by # more detailed zones. @@ -409,7 +443,7 @@ Zone Asia/Bahrain 3:22:20 - LMT 1920 # Manamah # From Paul Eggert (2014-08-21): # In tomorrow's The Hindu, Nitya Menon reports that India had two civil time # zones starting in 1884, one in Bombay and one in Calcutta, and that railways -# used a third time zone based on Madras time (80 deg. 18'30" E). Also, +# used a third time zone based on Madras time (80° 18' 30" E). Also, # in 1881 Bombay briefly switched to Madras time, but switched back. See: # http://www.thehindu.com/news/cities/chennai/madras-375-when-madras-clocked-the-time/article6339393.ece #Zone Asia/Chennai [not enough info to complete] @@ -532,7 +566,7 @@ Zone Europe/Belfast -0:23:40 - LMT 1880 Aug 2 # Data from Joseph S. Myers # https://mm.icann.org/pipermail/tz/2013-September/019883.html # References to be added -# LMT is for Town Church, St. Peter Port, 49 degrees 27'17"N 2 degrees 32'10"W +# LMT is for Town Church, St. Peter Port, 49° 27' 17" N, 2° 32' 10" W. Zone Europe/Guernsey -0:10:09 - LMT 1913 Jun 18 0:00 GB-Eire %s 1940 Jul 2 1:00 C-Eur CE%sT 1945 May 8 @@ -566,7 +600,7 @@ Zone Europe/Isle_of_Man -0:17:55 - LMT 1883 Mar 30 0:00s # Data from Joseph S. Myers # https://mm.icann.org/pipermail/tz/2013-September/019883.html # References to be added -# LMT is for Parish Church, St. Helier, 49 degrees 11'0.57"N 2 degrees 6'24.33"W +# LMT is for Parish Church, St. Helier, 49° 11' 0.57" N, 2° 6' 24.33" W. Zone Europe/Jersey -0:08:26 - LMT 1898 Jun 11 16:00u 0:00 GB-Eire %s 1940 Jul 2 1:00 C-Eur CE%sT 1945 May 8 diff --git a/contrib/tzdata/checktab.awk b/contrib/tzdata/checktab.awk index 2397673e92..393ab19f0b 100644 --- a/contrib/tzdata/checktab.awk +++ b/contrib/tzdata/checktab.awk @@ -126,6 +126,7 @@ $1 ~ /^#/ { next } if ($1 == "Zone") { tz = $2 ruleUsed[$4] = 1 + if ($5 ~ /%/) rulePercentUsed[$4] = 1 } else if ($1 == "Link" && zone_table == "zone.tab") { # Ignore Link commands if source and destination basenames # are identical, e.g. Europe/Istanbul versus Asia/Istanbul. @@ -136,8 +137,10 @@ $1 ~ /^#/ { next } if (src != dst) tz = $3 } else if ($1 == "Rule") { ruleDefined[$2] = 1 + if ($10 != "-") ruleLetters[$2] = 1 } else { ruleUsed[$2] = 1 + if ($3 ~ /%/) rulePercentUsed[$2] = 1 } if (tz && tz ~ /\//) { if (!tztab[tz]) { @@ -156,6 +159,12 @@ END { status = 1 } } + for (tz in ruleLetters) { + if (!rulePercentUsed[tz]) { + printf "%s: Rule contains letters never used\n", tz + status = 1 + } + } for (tz in tztab) { if (!zoneSeen[tz]) { printf "%s:%d: no Zone table for '%s'\n", \ diff --git a/contrib/tzdata/etcetera b/contrib/tzdata/etcetera index f5fa4c94b4..91ded935c4 100644 --- a/contrib/tzdata/etcetera +++ b/contrib/tzdata/etcetera @@ -1,9 +1,11 @@ +# tzdb data for ships at sea and other miscellany + # This file is in the public domain, so clarified as of # 2009-05-17 by Arthur David Olson. # These entries are mostly present for historical reasons, so that # people in areas not otherwise covered by the tz files could "zic -l" -# to a time zone that was right for their area. These days, the +# to a timezone that was right for their area. These days, the # tz files cover almost all the inhabited world, and the only practical # need now for the entries that are not on UTC are for ships at sea # that cannot use POSIX TZ settings. diff --git a/contrib/tzdata/europe b/contrib/tzdata/europe index 6c1ccbe455..587f7b03cc 100644 --- a/contrib/tzdata/europe +++ b/contrib/tzdata/europe @@ -1,3 +1,5 @@ +# tzdb data for Europe and environs + # This file is in the public domain, so clarified as of # 2009-05-17 by Arthur David Olson. @@ -117,8 +119,8 @@ # along the towpath within a few yards of it.' # # I have a one inch to one mile map of London and my estimate of the stone's -# position is 51 degrees 28' 30" N, 0 degrees 18' 45" W. The longitude should -# be within about +-2". The Ordnance Survey grid reference is TQ172761. +# position is 51° 28' 30" N, 0° 18' 45" W. The longitude should +# be within about ±2". The Ordnance Survey grid reference is TQ172761. # # [This yields GMTOFF = -0:01:15 for London LMT in the 18th century.] @@ -158,7 +160,7 @@ # after-hours daylight in which to pursue his research. # In 1895 he presented a paper to the Wellington Philosophical Society # that proposed a two-hour daylight-saving shift. See: -# Hudson GV. On seasonal time-adjustment in countries south of lat. 30 deg. +# Hudson GV. On seasonal time-adjustment in countries south of lat. 30°. # Transactions and Proceedings of the New Zealand Institute. 1895;28:734 # http://rsnz.natlib.govt.nz/volume/rsnz_28/rsnz_28_00_006110.html # Although some interest was expressed in New Zealand, his proposal @@ -508,19 +510,33 @@ Link Europe/London Europe/Jersey Link Europe/London Europe/Guernsey Link Europe/London Europe/Isle_of_Man -# From Paul Eggert (2018-01-19): +# From Paul Eggert (2018-02-15): +# In January 2018 we discovered that the negative SAVE values in the +# Eire rules cause problems with tests for ICU: +# https://mm.icann.org/pipermail/tz/2018-January/025825.html +# and with tests for OpenJDK: +# https://mm.icann.org/pipermail/tz/2018-January/025822.html +# +# To work around this problem, the build procedure can translate the +# following data into two forms, one with negative SAVE values and the +# other form with a traditional approximation for Irish timestamps +# after 1971-10-31 02:00 UTC; although this approximation has tm_isdst +# flags that are reversed, its UTC offsets are correct and this often +# suffices. This source file currently uses only nonnegative SAVE +# values, but this is intended to change and downstream code should +# not rely on it. +# # The following is like GB-Eire and EU, except with standard time in -# summer and negative daylight saving time in winter. -# Although currently commented out, this will need to become uncommented -# once the ICU/OpenJDK workaround is removed; see below. +# summer and negative daylight saving time in winter. It is for when +# negative SAVE values are used. # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S -#Rule Eire 1971 only - Oct 31 2:00u -1:00 GMT -#Rule Eire 1972 1980 - Mar Sun>=16 2:00u 0 IST -#Rule Eire 1972 1980 - Oct Sun>=23 2:00u -1:00 GMT -#Rule Eire 1981 max - Mar lastSun 1:00u 0 IST -#Rule Eire 1981 1989 - Oct Sun>=23 1:00u -1:00 GMT -#Rule Eire 1990 1995 - Oct Sun>=22 1:00u -1:00 GMT -#Rule Eire 1996 max - Oct lastSun 1:00u -1:00 GMT +Rule Eire 1971 only - Oct 31 2:00u -1:00 - +Rule Eire 1972 1980 - Mar Sun>=16 2:00u 0 - +Rule Eire 1972 1980 - Oct Sun>=23 2:00u -1:00 - +Rule Eire 1981 max - Mar lastSun 1:00u 0 - +Rule Eire 1981 1989 - Oct Sun>=23 1:00u -1:00 - +Rule Eire 1990 1995 - Oct Sun>=22 1:00u -1:00 - +Rule Eire 1996 max - Oct lastSun 1:00u -1:00 - # Zone NAME GMTOFF RULES FORMAT [UNTIL] Zone Europe/Dublin -0:25:00 - LMT 1880 Aug 2 @@ -533,24 +549,12 @@ Zone Europe/Dublin -0:25:00 - LMT 1880 Aug 2 0:00 1:00 IST 1947 Nov 2 2:00s 0:00 - GMT 1948 Apr 18 2:00s 0:00 GB-Eire GMT/IST 1968 Oct 27 -# From Paul Eggert (2018-01-18): -# The next line should look like this: -# 1:00 Eire IST/GMT -# However, in January 2018 we discovered that the Eire rules cause -# problems with tests for ICU: -# https://mm.icann.org/pipermail/tz/2018-January/025825.html -# and with tests for OpenJDK: -# https://mm.icann.org/pipermail/tz/2018-January/025822.html -# To work around this problem, use a traditional approximation for -# time stamps after 1971-10-31 02:00 UTC, to give ICU and OpenJDK -# developers breathing room to fix bugs. This approximation has -# correct UTC offsets, but results in tm_isdst flags are the reverse -# of what they should be. This workaround is temporary and should be -# removed reasonably soon. - 1:00 - IST 1971 Oct 31 2:00u - 0:00 GB-Eire GMT/IST 1996 - 0:00 EU GMT/IST -# End of workaround for ICU and OpenJDK bugs. +# The next line is for when negative SAVE values are used. + 1:00 Eire IST/GMT +# These three lines are for when SAVE values are always nonnegative. +# 1:00 - IST 1971 Oct 31 2:00u +# 0:00 GB-Eire GMT/IST 1996 +# 0:00 EU GMT/IST ############################################################################### @@ -968,18 +972,30 @@ Zone Europe/Sofia 1:33:16 - LMT 1880 # Please see the 'asia' file for Asia/Nicosia. # Czech Republic / Czechia +# +# From Paul Eggert (2018-04-15): +# The source for Czech data is: Kdy začíná a končí letní čas. 2018-04-15. +# https://kalendar.beda.cz/kdy-zacina-a-konci-letni-cas +# We know of no English-language name for historical Czech winter time; +# abbreviate it as "GMT", as it happened to be GMT. +# # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S -Rule Czech 1945 only - Apr 8 2:00s 1:00 S -Rule Czech 1945 only - Nov 18 2:00s 0 - +Rule Czech 1945 only - Apr Mon>=1 2:00s 1:00 S +Rule Czech 1945 only - Oct 1 2:00s 0 - Rule Czech 1946 only - May 6 2:00s 1:00 S Rule Czech 1946 1949 - Oct Sun>=1 2:00s 0 - -Rule Czech 1947 only - Apr 20 2:00s 1:00 S -Rule Czech 1948 only - Apr 18 2:00s 1:00 S +Rule Czech 1947 1948 - Apr Sun>=15 2:00s 1:00 S Rule Czech 1949 only - Apr 9 2:00s 1:00 S # Zone NAME GMTOFF RULES FORMAT [UNTIL] Zone Europe/Prague 0:57:44 - LMT 1850 0:57:44 - PMT 1891 Oct # Prague Mean Time - 1:00 C-Eur CE%sT 1944 Sep 17 2:00s + 1:00 C-Eur CE%sT 1945 May 9 + 1:00 Czech CE%sT 1946 Dec 1 3:00 +# Vanguard section, for zic and other parsers that support negative DST. + 1:00 -1:00 GMT 1947 Feb 23 2:00 +# Rearguard section, for parsers that do not support negative DST. +# 0:00 - GMT 1947 Feb 23 2:00 +# End of rearguard section. 1:00 Czech CE%sT 1979 1:00 EU CE%sT # Use Europe/Prague also for Slovakia. @@ -1534,21 +1550,21 @@ Zone Europe/Budapest 1:16:20 - LMT 1890 Oct # http://www.almanak.hi.is/klukkan.html # # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S -Rule Iceland 1917 1919 - Feb 19 23:00 1:00 S +Rule Iceland 1917 1919 - Feb 19 23:00 1:00 - Rule Iceland 1917 only - Oct 21 1:00 0 - Rule Iceland 1918 1919 - Nov 16 1:00 0 - -Rule Iceland 1921 only - Mar 19 23:00 1:00 S +Rule Iceland 1921 only - Mar 19 23:00 1:00 - Rule Iceland 1921 only - Jun 23 1:00 0 - -Rule Iceland 1939 only - Apr 29 23:00 1:00 S +Rule Iceland 1939 only - Apr 29 23:00 1:00 - Rule Iceland 1939 only - Oct 29 2:00 0 - -Rule Iceland 1940 only - Feb 25 2:00 1:00 S +Rule Iceland 1940 only - Feb 25 2:00 1:00 - Rule Iceland 1940 1941 - Nov Sun>=2 1:00s 0 - -Rule Iceland 1941 1942 - Mar Sun>=2 1:00s 1:00 S +Rule Iceland 1941 1942 - Mar Sun>=2 1:00s 1:00 - # 1943-1946 - first Sunday in March until first Sunday in winter -Rule Iceland 1943 1946 - Mar Sun>=1 1:00s 1:00 S +Rule Iceland 1943 1946 - Mar Sun>=1 1:00s 1:00 - Rule Iceland 1942 1948 - Oct Sun>=22 1:00s 0 - # 1947-1967 - first Sunday in April until first Sunday in winter -Rule Iceland 1947 1967 - Apr Sun>=1 1:00s 1:00 S +Rule Iceland 1947 1967 - Apr Sun>=1 1:00s 1:00 - # 1949 and 1967 Oct transitions delayed by 1 week Rule Iceland 1949 only - Oct 30 1:00s 0 - Rule Iceland 1950 1966 - Oct Sun>=22 1:00s 0 - @@ -2014,7 +2030,7 @@ Rule Neth 1938 1939 - May 15 2:00s 1:00 S Rule Neth 1945 only - Apr 2 2:00s 1:00 S Rule Neth 1945 only - Sep 16 2:00s 0 - # -# Amsterdam Mean Time was +00:19:32.13 exactly, but the .13 is omitted +# Amsterdam Mean Time was +00:19:32.13, but the .13 is omitted # below because the current format requires GMTOFF to be an integer. # Zone NAME GMTOFF RULES FORMAT [UNTIL] Zone Europe/Amsterdam 0:19:32 - LMT 1835 @@ -2138,15 +2154,19 @@ Zone Europe/Warsaw 1:24:00 - LMT 1880 1:00 EU CE%sT # Portugal -# + # From Paul Eggert (2014-08-11), after a heads-up from Stephen Colebourne: # According to a Portuguese decree (1911-05-26) # https://dre.pt/application/dir/pdf1sdip/1911/05/12500/23132313.pdf # Lisbon was at -0:36:44.68, but switched to GMT on 1912-01-01 at 00:00. -# Round the old offset to -0:36:45. This agrees with Willett but disagrees -# with Shanks, who says the transition occurred on 1911-05-24 at 00:00 for -# Europe/Lisbon, Atlantic/Azores, and Atlantic/Madeira. +# Round the old offset to -0:36:45. This agrees with Willett.... # +# From Michael Deckers (2018-02-15): +# article 5 [of the 1911 decree; Deckers's translation] ...: +# These dispositions shall enter into force at the instant at which, +# according to the 2nd article, the civil day January 1, 1912 begins, +# all clocks therefore having to be advanced or set back correspondingly ... + # From Rui Pedro Salgueiro (1992-11-12): # Portugal has recently (September, 27) changed timezone # (from WET to MET or CET) to harmonize with EEC. @@ -2229,7 +2249,7 @@ Rule Port 1983 only - Mar lastSun 2:00s 1:00 S # # Zone NAME GMTOFF RULES FORMAT [UNTIL] Zone Europe/Lisbon -0:36:45 - LMT 1884 - -0:36:45 - LMT 1912 Jan 1 # Lisbon Mean Time + -0:36:45 - LMT 1912 Jan 1 0:00u # Lisbon MT 0:00 Port WE%sT 1966 Apr 3 2:00 1:00 - CET 1976 Sep 26 1:00 0:00 Port WE%sT 1983 Sep 25 1:00s @@ -2238,7 +2258,7 @@ Zone Europe/Lisbon -0:36:45 - LMT 1884 0:00 EU WE%sT # This Zone can be simplified once we assume zic %z. Zone Atlantic/Azores -1:42:40 - LMT 1884 # Ponta Delgada - -1:54:32 - HMT 1912 Jan 1 # Horta Mean Time + -1:54:32 - HMT 1912 Jan 1 2:00u # Horta MT -2:00 Port -02/-01 1942 Apr 25 22:00s -2:00 Port +00 1942 Aug 15 22:00s -2:00 Port -02/-01 1943 Apr 17 22:00s @@ -2254,7 +2274,7 @@ Zone Atlantic/Azores -1:42:40 - LMT 1884 # Ponta Delgada -1:00 EU -01/+00 # This Zone can be simplified once we assume zic %z. Zone Atlantic/Madeira -1:07:36 - LMT 1884 # Funchal - -1:07:36 - FMT 1912 Jan 1 # Funchal Mean Time + -1:07:36 - FMT 1912 Jan 1 1:00u # Funchal MT -1:00 Port -01/+00 1942 Apr 25 22:00s -1:00 Port +01 1942 Aug 15 22:00s -1:00 Port -01/+00 1943 Apr 17 22:00s @@ -2409,6 +2429,33 @@ Zone Europe/Bucharest 1:44:24 - LMT 1891 Oct # administratively part of Sakhalin oblast', they appear to have # remained on UTC+11 along with Magadan. +# From Marat Nigametzianov (2018-07-16): +# this is link to order from 1956 about timezone in USSR +# http://astro.uni-altai.ru/~orion/blog/2011/11/novyie-granitsyi-chasovyih-poyasov-v-sssr/ +# +# From Paul Eggert (2018-07-16): +# Perhaps someone could translate the above-mentioned link and use it +# to correct our data for the ex-Soviet Union. It cites the following: +# «Поясное время и новые границы часовых поясов» / сост. П.Н. Долгов, +# отв. ред. Г.Д. Бурдун - М: Комитет стандартов, мер и измерительных +# приборов при Совете Министров СССР, Междуведомственная комиссия +# единой службы времени, 1956 г. +# This book looks like it would be a helpful resource for the Soviet +# Union through 1956. Although a copy was in the Scientific Library +# of Tomsk State University, I have not been able to track down a copy nearby. +# +# From Stepan Golosunov (2018-07-21): +# http://astro.uni-altai.ru/~orion/blog/2015/05/center-reforma-ischisleniya-vremeni-br-na-territorii-sssr-v-1957-godu-center/ +# says that the 1956 decision to change time belts' borders was not +# implemented as planned in 1956 and the change happened in 1957. +# There is also the problem that actual time zones were different from +# the official time belts (and from many time belts' maps) as there were +# numerous exceptions to application of time belt rules. For example, +# https://ru.wikipedia.org/wiki/Московское_время#Перемещение_границы_применения_московского_времени_на_восток +# says that by 1962 there were many regions in the 3rd time belt that +# were on Moscow time, referring to a 1962 map. By 1989 number of such +# exceptions grew considerably. + # From Tim Parenti (2014-07-06): # The comments detailing the coverage of each Russian zone are meant to assist # with maintenance only and represent our best guesses as to which regions @@ -2419,9 +2466,6 @@ Zone Europe/Bucharest 1:44:24 - LMT 1891 Oct # future stability. ISO 3166-2:RU codes are also listed for first-level # divisions where available. -# Zone NAME GMTOFF RULES FORMAT [UNTIL] - - # From Tim Parenti (2014-07-03): # Europe/Kaliningrad covers... # 39 RU-KGD Kaliningrad Oblast @@ -2592,13 +2636,13 @@ Zone Europe/Kaliningrad 1:22:00 - LMT 1893 Apr # From Vladimir Karpinsky (2014-07-08): # LMT in Moscow (before Jul 3, 1916) is 2:30:17, that was defined by Moscow -# Observatory (coordinates: 55 deg. 45'29.70", 37 deg. 34'05.30").... +# Observatory (coordinates: 55° 45' 29.70", 37° 34' 05.30").... # LMT in Moscow since Jul 3, 1916 is 2:31:01 as a result of new standard. # (The info is from the book by Byalokoz ... p. 18.) # The time in St. Petersburg as capital of Russia was defined by # Pulkov observatory, near St. Petersburg. In 1916 LMT Moscow # was synchronized with LMT St. Petersburg (+30 minutes), (Pulkov observatory -# coordinates: 59 deg. 46'18.70", 30 deg. 19'40.70") so 30 deg. 19'40.70" > +# coordinates: 59° 46' 18.70", 30° 19' 40.70") so 30° 19' 40.70" > # 2h01m18.7s = 2:01:19. LMT Moscow = LMT St.Petersburg + 30m 2:01:19 + 0:30 = # 2:31:19 ... # @@ -2689,6 +2733,15 @@ Zone Europe/Astrakhan 3:12:12 - LMT 1924 May # 34 RU-VGG Volgograd Oblast # The 1988 transition is from USSR act No. 5 (1988-01-04). +# From Alexander Fetisov (2018-09-20): +# Volgograd region in southern Russia (Europe/Volgograd) change +# timezone from UTC+3 to UTC+4 from 28oct2018. +# http://sozd.parliament.gov.ru/bill/452878-7 +# +# From Stepan Golosunov (2018-10-11): +# The law has been published today on +# http://publication.pravo.gov.ru/Document/View/0001201810110037 + Zone Europe/Volgograd 2:57:40 - LMT 1920 Jan 3 3:00 - +03 1930 Jun 21 4:00 - +04 1961 Nov 11 @@ -2697,7 +2750,8 @@ Zone Europe/Volgograd 2:57:40 - LMT 1920 Jan 3 4:00 - +04 1992 Mar 29 2:00s 3:00 Russia +03/+04 2011 Mar 27 2:00s 4:00 - +04 2014 Oct 26 2:00s - 3:00 - +03 + 3:00 - +03 2018 Oct 28 2:00s + 4:00 - +04 # From Paul Eggert (2016-11-11): # Europe/Saratov covers: @@ -3386,7 +3440,8 @@ Rule Spain 1978 only - Oct 1 2:00s 0 - #Rule NatSpain 1937 only - May 22 23:00 1:00 S #Rule NatSpain 1937 1938 - Oct Sat>=1 24:00s 0 - #Rule NatSpain 1938 only - Mar 26 23:00 1:00 S -# The following rules are copied from Morocco from 1967 through 1978. +# The following rules are copied from Morocco from 1967 through 1978, +# except with "S" letters. Rule SpainAfrica 1967 only - Jun 3 12:00 1:00 S Rule SpainAfrica 1967 only - Oct 1 0:00 0 - Rule SpainAfrica 1974 only - Jun 24 0:00 1:00 S @@ -3406,6 +3461,7 @@ Zone Africa/Ceuta -0:21:16 - LMT 1900 Dec 31 23:38:44 0:00 1:00 WEST 1918 Oct 7 23:00 0:00 - WET 1924 0:00 Spain WE%sT 1929 + 0:00 - WET 1967 # Help zishrink.awk. 0:00 SpainAfrica WE%sT 1984 Mar 16 1:00 - CET 1986 1:00 EU CE%sT @@ -3427,7 +3483,7 @@ Zone Atlantic/Canary -1:01:36 - LMT 1922 Mar # Las Palmas de Gran C. # three degrees, or twelve minutes of time, to the west of the # meridian of the Observatory of Stockholm". The law is dated 1878-05-31. # -# The observatory at that time had the meridian 18 degrees 03' 30" +# The observatory at that time had the meridian 18° 03' 30" # eastern longitude = 01:12:14 in time. Less 12 minutes gives the # national standard time as 01:00:14 ahead of GMT.... # @@ -3531,7 +3587,7 @@ Zone Europe/Stockholm 1:12:12 - LMT 1879 Jan 1 # From Alois Treindl (2013-09-11): # The Federal regulations say # https://www.admin.ch/opc/de/classified-compilation/20071096/index.html -# ... the meridian for Bern mean time ... is 7 degrees 26' 22.50". +# ... the meridian for Bern mean time ... is 7° 26' 22.50". # Expressed in time, it is 0h29m45.5s. # From Pierre-Yves Berger (2013-09-11): @@ -3591,7 +3647,7 @@ Zone Europe/Zurich 0:34:08 - LMT 1853 Jul 16 # See above comment. # http://www.resmigazete.gov.tr/eskiler/2001/03/20010324.htm#2 - for 2001 # http://www.resmigazete.gov.tr/eskiler/2002/03/20020316.htm#2 - for 2002-2006 # From Paul Eggert (2016-09-25): -# Prefer the above sources to Shanks & Pottenger for time stamps after 1985. +# Prefer the above sources to Shanks & Pottenger for timestamps after 1985. # From Steffen Thorsen (2007-03-09): # Starting 2007 though, it seems that they are adopting EU's 1:00 UTC @@ -3801,10 +3857,29 @@ Link Europe/Istanbul Asia/Istanbul # Istanbul is in both continents. # * Ukrainian Government's Resolution of 20.03.1992, No. 139. # http://www.uazakon.com/documents/date_8u/pg_grcasa.htm +# From Paul Eggert (2018-10-03): +# As is usual in tzdb, Ukrainian zones use the most common English spellings. +# For example, tzdb uses Europe/Kiev, as "Kiev" is the most common spelling in +# English for Ukraine's capital, even though it is certainly wrong as a +# transliteration of the Ukrainian "Київ". This is similar to tzdb's use of +# Europe/Prague, which is certainly wrong as a transliteration of the Czech +# "Praha". ("Kiev" came from old Slavic via Russian to English, and "Prague" +# came from old Slavic via French to English, so the two cases have something +# in common.) Admittedly English-language spelling of Ukrainian names is +# controversial, and some day "Kyiv" may become substantially more popular in +# English; in the meantime, stick with the traditional English "Kiev" as that +# means less disruption for our users. +# +# Anyway, none of the common English-language spellings (Kiev, Kyiv, Kieff, +# Kijeff, Kijev, Kiyef, Kiyeff) do justice to the common pronunciation in +# Ukrainian, namely [ˈkɪjiu̯] (IPA). This pronunciation has nothing like an +# English "v" or "f", and instead trails off with what an English-speaker +# would call a demure "oo" sound, and it would would be better anglicized as +# "Kuiyu". Here's a sound file, if you would like to do as the Kuiyuvians do: +# https://commons.wikimedia.org/wiki/File:Uk-Київ.ogg + # Zone NAME GMTOFF RULES FORMAT [UNTIL] -# Most of Ukraine since 1970 has been like Kiev. -# "Kyiv" is the transliteration of the Ukrainian name, but -# "Kiev" is more common in English. +# This represents most of Ukraine. See above for the spelling of "Kiev". Zone Europe/Kiev 2:02:04 - LMT 1880 2:02:04 - KMT 1924 May 2 # Kiev Mean Time 2:00 - EET 1930 Jun 21 diff --git a/contrib/tzdata/factory b/contrib/tzdata/factory index 75fa4a11c3..d4e76599cd 100644 --- a/contrib/tzdata/factory +++ b/contrib/tzdata/factory @@ -1,8 +1,10 @@ +# tzdb data for noncommittal factory settings + # This file is in the public domain, so clarified as of # 2009-05-17 by Arthur David Olson. -# For distributors who don't want to put time zone specification in -# their installation procedures. Users that run 'date' will get the +# For distributors who don't want to specify a timezone in their +# installation procedures. Users who run 'date' will get the # time zone abbreviation "-00", indicating that the actual time zone # is unknown. diff --git a/contrib/tzdata/leap-seconds.list b/contrib/tzdata/leap-seconds.list index eab6ab869c..cf54b9aa3e 100644 --- a/contrib/tzdata/leap-seconds.list +++ b/contrib/tzdata/leap-seconds.list @@ -204,10 +204,10 @@ # current -- the update time stamp, the data and the name of the file # will not change. # -# Updated through IERS Bulletin C55 -# File expires on: 28 December 2018 +# Updated through IERS Bulletin C56 +# File expires on: 28 June 2019 # -#@ 3754944000 +#@ 3770668800 # 2272060800 10 # 1 Jan 1972 2287785600 11 # 1 Jul 1972 @@ -252,4 +252,4 @@ # the hash line is also ignored in the # computation. # -#h 44dcf58c e28d25aa b36612c8 f3d3e8b5 a8fdf478 +#h 62ca19f6 96a4ae0a 3708451c 9f8693f4 016604eb diff --git a/contrib/tzdata/leapseconds b/contrib/tzdata/leapseconds index 358e741052..148aa8ee3e 100644 --- a/contrib/tzdata/leapseconds +++ b/contrib/tzdata/leapseconds @@ -3,21 +3,25 @@ # This file is in the public domain. # This file is generated automatically from the data in the public-domain -# leap-seconds.list file, which is copied from: -# ftp://ftp.nist.gov/pub/time/leap-seconds.list +# leap-seconds.list file, which can be copied from +# +# or +# or . # For more about leap-seconds.list, please see # The NTP Timescale and Leap Seconds -# https://www.eecis.udel.edu/~mills/leap.html +# . # The International Earth Rotation and Reference Systems Service # periodically uses leap seconds to keep UTC to within 0.9 s of UT1 -# (which measures the true angular orientation of the earth in space); see -# Levine J. Coordinated Universal Time and the leap second. +# (which measures the true angular orientation of the earth in space) +# and publishes leap second data in a copyrighted file +# . +# See: Levine J. Coordinated Universal Time and the leap second. # URSI Radio Sci Bull. 2016;89(4):30-6. doi:10.23919/URSIRSB.2016.7909995 -# http://ieeexplore.ieee.org/document/7909995/ +# . # There were no leap seconds before 1972, because the official mechanism # accounting for the discrepancy between atomic time and the earth's rotation -# did not exist until the early 1970s. +# did not exist. # The correction (+ or -) is made at the given time, so lines # will typically look like: @@ -25,10 +29,7 @@ # or # Leap YEAR MON DAY 23:59:59 - R/S -# If the leapsecond is Rolling (R) the given time is local time. -# If the leapsecond is Stationary (S) the given time is UTC. - -# Leap YEAR MONTH DAY HH:MM:SS CORR R/S +# If the leap second is Rolling (R) the given time is local time (unused here). Leap 1972 Jun 30 23:59:60 + S Leap 1972 Dec 31 23:59:60 + S Leap 1973 Dec 31 23:59:60 + S @@ -57,5 +58,9 @@ Leap 2012 Jun 30 23:59:60 + S Leap 2015 Jun 30 23:59:60 + S Leap 2016 Dec 31 23:59:60 + S -# Updated through IERS Bulletin C55 -# File expires on: 28 December 2018 +# POSIX timestamps for the data in this file: +#updated 1467936000 +#expires 1561680000 + +# Updated through IERS Bulletin C56 +# File expires on: 28 June 2019 diff --git a/contrib/tzdata/leapseconds.awk b/contrib/tzdata/leapseconds.awk index 66eb64d3dc..ea0567cd7f 100644 --- a/contrib/tzdata/leapseconds.awk +++ b/contrib/tzdata/leapseconds.awk @@ -8,21 +8,25 @@ BEGIN { print "# This file is in the public domain." print "" print "# This file is generated automatically from the data in the public-domain" - print "# leap-seconds.list file, which is copied from:" - print "# ftp://ftp.nist.gov/pub/time/leap-seconds.list" + print "# leap-seconds.list file, which can be copied from" + print "# " + print "# or " + print "# or ." print "# For more about leap-seconds.list, please see" print "# The NTP Timescale and Leap Seconds" - print "# https://www.eecis.udel.edu/~mills/leap.html" + print "# ." print "" print "# The International Earth Rotation and Reference Systems Service" print "# periodically uses leap seconds to keep UTC to within 0.9 s of UT1" - print "# (which measures the true angular orientation of the earth in space); see" - print "# Levine J. Coordinated Universal Time and the leap second." + print "# (which measures the true angular orientation of the earth in space)" + print "# and publishes leap second data in a copyrighted file" + print "# ." + print "# See: Levine J. Coordinated Universal Time and the leap second." print "# URSI Radio Sci Bull. 2016;89(4):30-6. doi:10.23919/URSIRSB.2016.7909995" - print "# http://ieeexplore.ieee.org/document/7909995/" + print "# ." print "# There were no leap seconds before 1972, because the official mechanism" print "# accounting for the discrepancy between atomic time and the earth's rotation" - print "# did not exist until the early 1970s." + print "# did not exist." print "" print "# The correction (+ or -) is made at the given time, so lines" print "# will typically look like:" @@ -30,18 +34,35 @@ BEGIN { print "# or" print "# Leap YEAR MON DAY 23:59:59 - R/S" print "" - print "# If the leapsecond is Rolling (R) the given time is local time." - print "# If the leapsecond is Stationary (S) the given time is UTC." - print "" - print "# Leap YEAR MONTH DAY HH:MM:SS CORR R/S" -} + print "# If the leap second is Rolling (R) the given time is local time (unused here)." -/^ *$/ { next } + monthabbr[ 1] = "Jan" + monthabbr[ 2] = "Feb" + monthabbr[ 3] = "Mar" + monthabbr[ 4] = "Apr" + monthabbr[ 5] = "May" + monthabbr[ 6] = "Jun" + monthabbr[ 7] = "Jul" + monthabbr[ 8] = "Aug" + monthabbr[ 9] = "Sep" + monthabbr[10] = "Oct" + monthabbr[11] = "Nov" + monthabbr[12] = "Dec" + for (i in monthabbr) { + monthnum[monthabbr[i]] = i + monthlen[i] = 31 + } + monthlen[2] = 28 + monthlen[4] = monthlen[6] = monthlen[9] = monthlen[11] = 30 +} /^#\tUpdated through/ || /^#\tFile expires on:/ { last_lines = last_lines $0 "\n" } +/^#[$][ \t]/ { updated = $2 } +/^#[@][ \t]/ { expires = $2 } + /^#/ { next } { @@ -57,19 +78,28 @@ BEGIN { } else { sign = "23:59:59\t-" } - if (month == "Jan") { + m = monthnum[month] - 1 + if (m == 0) { year--; - month = "Dec"; - day = 31 - } else if (month == "Jul") { - month = "Jun"; - day = 30 + m = 12 } + month = monthabbr[m] + day = monthlen[m] + day += m == 2 && year % 4 == 0 && (year % 100 != 0 || year % 400 == 0) printf "Leap\t%s\t%s\t%s\t%s\tS\n", year, month, day, sign } old_TAI_minus_UTC = TAI_minus_UTC } END { + # The difference between the NTP and POSIX epochs is 70 years + # (including 17 leap days), each 24 hours of 60 minutes of 60 + # seconds each. + epoch_minus_NTP = ((1970 - 1900) * 365 + 17) * 24 * 60 * 60 + + print "" + print "# POSIX timestamps for the data in this file:" + printf "#updated %s\n", updated - epoch_minus_NTP + printf "#expires %s\n", expires - epoch_minus_NTP printf "\n%s", last_lines } diff --git a/contrib/tzdata/northamerica b/contrib/tzdata/northamerica index a014126e18..9d5bad2f7b 100644 --- a/contrib/tzdata/northamerica +++ b/contrib/tzdata/northamerica @@ -1,3 +1,5 @@ +# tzdb data for North and Central America and environs + # This file is in the public domain, so clarified as of # 2009-05-17 by Arthur David Olson. @@ -25,7 +27,7 @@ # in New York City (1869-10). His 1870 proposal was based on Washington, DC, # but in 1872-05 he moved the proposed origin to Greenwich. -# From Paul Eggert (2016-09-21): +# From Paul Eggert (2018-03-20): # Dowd's proposal left many details unresolved, such as where to draw # lines between time zones. The key individual who made time zones # work in the US was William Frederick Allen - railway engineer, @@ -36,10 +38,9 @@ # to the General Time Convention on 1883-04-11, saying that his plan # meant "local time would be practically abolished" - a plus for # railway scheduling. By the next convention on 1883-10-11 nearly all -# railroads had agreed and it took effect on 1883-11-18 at 12:00. -# That Sunday was called the "day of two noons", as the eastern parts -# of the new zones observed noon twice. Allen witnessed the -# transition in New York City, writing: +# railroads had agreed and it took effect on 1883-11-18. That Sunday +# was called the "day of two noons", as some locations observed noon +# twice. Allen witnessed the transition in New York City, writing: # # I heard the bells of St. Paul's strike on the old time. Four # minutes later, obedient to the electrical signal from the Naval @@ -49,7 +50,7 @@ # # Most of the US soon followed suit. See: # Bartky IR. The adoption of standard time. Technol Cult 1989 Jan;30(1):25-56. -# http://dx.doi.org/10.2307/3105430 +# https://dx.doi.org/10.2307/3105430 # From Paul Eggert (2005-04-16): # That 1883 transition occurred at 12:00 new time, not at 12:00 old time. @@ -424,8 +425,7 @@ Zone America/North_Dakota/New_Salem -6:45:39 - LMT 1883 Nov 18 12:14:21 # ...according to the Census Bureau, the largest city is Beulah (although # it's commonly referred to as Beulah-Hazen, with Hazen being the next # largest city in Mercer County). Google Maps places Beulah's city hall -# at 47 degrees 15' 51" N, 101 degrees 46' 40" W, which yields an offset -# of 6h47'07". +# at 47° 15' 51" N, 101° 46' 40" W, which yields an offset of 6h47'07". Zone America/North_Dakota/Beulah -6:47:07 - LMT 1883 Nov 18 12:12:53 -7:00 US M%sT 2010 Nov 7 2:00 @@ -439,6 +439,19 @@ Zone America/North_Dakota/Beulah -6:47:07 - LMT 1883 Nov 18 12:12:53 # western South Dakota, far western Texas (El Paso County, Hudspeth County, # and Pine Springs and Nickel Creek in Culberson County), Utah, Wyoming # +# From Paul Eggert (2018-10-25): +# On 1921-03-04 federal law placed all of Texas into the central time zone. +# However, El Paso ignored the law for decades and continued to observe +# mountain time, on the grounds that that's what they had always done +# and they weren't about to let the federal government tell them what to do. +# Eventually the federal government gave in and changed the law on +# 1970-04-10 to match what El Paso was actually doing. Although +# that's slightly after our 1970 cutoff, there is no need to create a +# separate zone for El Paso since they were ignoring the law anyway. See: +# Long T. El Pasoans were time rebels, fought to stay in Mountain zone. +# El Paso Times. 2018-10-24 06:40 -06. +# https://www.elpasotimes.com/story/news/local/el-paso/2018/10/24/el-pasoans-were-time-rebels-fought-stay-mountain-zone/1744509002/ +# # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER Rule Denver 1920 1921 - Mar lastSun 2:00 1:00 D Rule Denver 1920 only - Oct lastSun 2:00 0 S @@ -458,7 +471,7 @@ Zone America/Denver -6:59:56 - LMT 1883 Nov 18 12:00:04 # California, northern Idaho (Benewah, Bonner, Boundary, Clearwater, # Kootenai, Latah, Lewis, Nez Perce, and Shoshone counties, Idaho county # north of the Salmon River, and the towns of Burgdorf and Warren), -# Nevada (except West Wendover), Oregon (except the northern 3/4 of +# Nevada (except West Wendover), Oregon (except the northern ¾ of # Malheur county), and Washington # From Paul Eggert (2016-08-20): @@ -708,9 +721,7 @@ Zone America/Adak 12:13:22 - LMT 1867 Oct 19 12:44:35 Zone Pacific/Honolulu -10:31:26 - LMT 1896 Jan 13 12:00 -10:30 - HST 1933 Apr 30 2:00 -10:30 1:00 HDT 1933 May 21 12:00 - -10:30 - HST 1942 Feb 9 2:00 - -10:30 1:00 HDT 1945 Sep 30 2:00 - -10:30 - HST 1947 Jun 8 2:00 + -10:30 US H%sT 1947 Jun 8 2:00 -10:00 - HST # Now we turn to US areas that have diverged from the consensus since 1970. @@ -956,6 +967,13 @@ Zone America/Indiana/Vevay -5:40:16 - LMT 1883 Nov 18 12:19:44 -5:00 - EST 2006 -5:00 US E%sT +# From Paul Eggert (2018-03-20): +# The Louisville & Nashville Railroad's 1883-11-18 change occurred at +# 10:00 old local time; train were supposed to come to a standstill +# for precisely 18 minutes. See Bartky Fig. 1 (page 50). It is not +# clear how this matched civil time in Louisville, so for now continue +# to assume Louisville switched at noon new local time, like New York. +# # Part of Kentucky left its clocks alone in 1974. # This also includes Clark, Floyd, and Harrison counties in Indiana. # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER @@ -3264,8 +3282,8 @@ Zone America/Tegucigalpa -5:48:52 - LMT 1921 Apr # http://www.jamaicaobserver.com/columns/The-politician-in-all-of-us_17573647 # # Zone NAME GMTOFF RULES FORMAT [UNTIL] -Zone America/Jamaica -5:07:11 - LMT 1890 # Kingston - -5:07:11 - KMT 1912 Feb # Kingston Mean Time +Zone America/Jamaica -5:07:10 - LMT 1890 # Kingston + -5:07:10 - KMT 1912 Feb # Kingston Mean Time -5:00 - EST 1974 -5:00 US E%sT 1984 -5:00 - EST @@ -3415,7 +3433,7 @@ Zone America/Miquelon -3:44:40 - LMT 1911 May 15 # St Pierre # # Zone NAME GMTOFF RULES FORMAT [UNTIL] Zone America/Grand_Turk -4:44:32 - LMT 1890 - -5:07:11 - KMT 1912 Feb # Kingston Mean Time + -5:07:10 - KMT 1912 Feb # Kingston Mean Time -5:00 - EST 1979 -5:00 US E%sT 2015 Nov Sun>=1 2:00 -4:00 - AST 2018 Mar 11 3:00 diff --git a/contrib/tzdata/pacificnew b/contrib/tzdata/pacificnew index 734943486b..0e6cf07923 100644 --- a/contrib/tzdata/pacificnew +++ b/contrib/tzdata/pacificnew @@ -1,3 +1,5 @@ +# tzdb data for proposed US election time (this file is obsolete) + # This file is in the public domain, so clarified as of # 2009-05-17 by Arthur David Olson. diff --git a/contrib/tzdata/southamerica b/contrib/tzdata/southamerica index 2049177184..b66cb88b13 100644 --- a/contrib/tzdata/southamerica +++ b/contrib/tzdata/southamerica @@ -1,3 +1,5 @@ +# tzdb data for South America and environs + # This file is in the public domain, so clarified as of # 2009-05-17 by Arthur David Olson. @@ -47,28 +49,28 @@ # AR was chosen because they are the ISO letters that represent Argentina. # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S -Rule Arg 1930 only - Dec 1 0:00 1:00 S +Rule Arg 1930 only - Dec 1 0:00 1:00 - Rule Arg 1931 only - Apr 1 0:00 0 - -Rule Arg 1931 only - Oct 15 0:00 1:00 S +Rule Arg 1931 only - Oct 15 0:00 1:00 - Rule Arg 1932 1940 - Mar 1 0:00 0 - -Rule Arg 1932 1939 - Nov 1 0:00 1:00 S -Rule Arg 1940 only - Jul 1 0:00 1:00 S +Rule Arg 1932 1939 - Nov 1 0:00 1:00 - +Rule Arg 1940 only - Jul 1 0:00 1:00 - Rule Arg 1941 only - Jun 15 0:00 0 - -Rule Arg 1941 only - Oct 15 0:00 1:00 S +Rule Arg 1941 only - Oct 15 0:00 1:00 - Rule Arg 1943 only - Aug 1 0:00 0 - -Rule Arg 1943 only - Oct 15 0:00 1:00 S +Rule Arg 1943 only - Oct 15 0:00 1:00 - Rule Arg 1946 only - Mar 1 0:00 0 - -Rule Arg 1946 only - Oct 1 0:00 1:00 S +Rule Arg 1946 only - Oct 1 0:00 1:00 - Rule Arg 1963 only - Oct 1 0:00 0 - -Rule Arg 1963 only - Dec 15 0:00 1:00 S +Rule Arg 1963 only - Dec 15 0:00 1:00 - Rule Arg 1964 1966 - Mar 1 0:00 0 - -Rule Arg 1964 1966 - Oct 15 0:00 1:00 S +Rule Arg 1964 1966 - Oct 15 0:00 1:00 - Rule Arg 1967 only - Apr 2 0:00 0 - -Rule Arg 1967 1968 - Oct Sun>=1 0:00 1:00 S +Rule Arg 1967 1968 - Oct Sun>=1 0:00 1:00 - Rule Arg 1968 1969 - Apr Sun>=1 0:00 0 - -Rule Arg 1974 only - Jan 23 0:00 1:00 S +Rule Arg 1974 only - Jan 23 0:00 1:00 - Rule Arg 1974 only - May 1 0:00 0 - -Rule Arg 1988 only - Dec 1 0:00 1:00 S +Rule Arg 1988 only - Dec 1 0:00 1:00 - # # From Hernan G. Otero (1995-06-26): # These corrections were contributed by InterSoft Argentina S.A., @@ -76,7 +78,7 @@ Rule Arg 1988 only - Dec 1 0:00 1:00 S # Talleres de Hidrografía Naval Argentina # (Argentine Naval Hydrography Institute) Rule Arg 1989 1993 - Mar Sun>=1 0:00 0 - -Rule Arg 1989 1992 - Oct Sun>=15 0:00 1:00 S +Rule Arg 1989 1992 - Oct Sun>=15 0:00 1:00 - # # From Hernan G. Otero (1995-06-26): # From this moment on, the law that mandated the daylight saving @@ -87,7 +89,7 @@ Rule Arg 1989 1992 - Oct Sun>=15 0:00 1:00 S # On October 3, 1999, 0:00 local, Argentina implemented daylight savings time, # which did not result in the switch of a time zone, as they stayed 9 hours # from the International Date Line. -Rule Arg 1999 only - Oct Sun>=1 0:00 1:00 S +Rule Arg 1999 only - Oct Sun>=1 0:00 1:00 - # From Paul Eggert (2007-12-28): # DST was set to expire on March 5, not March 3, but since it was converted # to standard time on March 3 it's more convenient for us to pretend that @@ -190,9 +192,9 @@ Rule Arg 2000 only - Mar 3 0:00 0 - # la modificación del huso horario, ya que 2009 nos encuentra con # crecimiento en la producción y distribución energética." -Rule Arg 2007 only - Dec 30 0:00 1:00 S +Rule Arg 2007 only - Dec 30 0:00 1:00 - Rule Arg 2008 2009 - Mar Sun>=15 0:00 0 - -Rule Arg 2008 only - Oct Sun>=15 0:00 1:00 S +Rule Arg 2008 only - Oct Sun>=15 0:00 1:00 - # From Mariano Absatz (2004-05-21): # Today it was officially published that the Province of Mendoza is changing @@ -202,12 +204,14 @@ Rule Arg 2008 only - Oct Sun>=15 0:00 1:00 S # It's Law No. 7,210. This change is due to a public power emergency, so for # now we'll assume it's for this year only. # -# From Paul Eggert (2014-08-09): +# From Paul Eggert (2018-01-31): # Hora de verano para la República Argentina # http://buenasiembra.com.ar/esoterismo/astrologia/hora-de-verano-de-la-republica-argentina-27.html # says that standard time in Argentina from 1894-10-31 # to 1920-05-01 was -4:16:48.25. Go with this more-precise value -# over Shanks & Pottenger. +# over Shanks & Pottenger. It is upward compatible with Milne, who +# says Córdoba time was -4:16:48.2. + # # From Mariano Absatz (2004-06-05): # These media articles from a major newspaper mostly cover the current state: @@ -381,19 +385,16 @@ Rule Arg 2008 only - Oct Sun>=15 0:00 1:00 S # rules...San Luis is still using "Western ARgentina Time" and it got # stuck on Summer daylight savings time even though the summer is over. -# From Paul Eggert (2013-09-05): +# From Paul Eggert (2018-01-23): # Perhaps San Luis operates on the legal fiction that it is at -04 -# with perpetual summer time, but ordinary usage typically seems to +# with perpetual daylight saving time, but ordinary usage typically seems to # just say it's at -03; see, for example, # https://es.wikipedia.org/wiki/Hora_oficial_argentina # We've documented similar situations as being plain changes to # standard time, so let's do that here too. This does not change UTC # offsets, only tm_isdst and the time zone abbreviations. One minor # plus is that this silences a zic complaint that there's no POSIX TZ -# setting for time stamps past 2038. - -# From Paul Eggert (2013-02-21): -# Milne says Córdoba time was -4:16:48.2. Round to the nearest second. +# setting for timestamps past 2038. # Zone NAME GMTOFF RULES FORMAT [UNTIL] # @@ -529,7 +530,7 @@ Zone America/Argentina/Mendoza -4:35:16 - LMT 1894 Oct 31 # San Luis (SL) Rule SanLuis 2008 2009 - Mar Sun>=8 0:00 0 - -Rule SanLuis 2007 2008 - Oct Sun>=8 0:00 1:00 S +Rule SanLuis 2007 2008 - Oct Sun>=8 0:00 1:00 - Zone America/Argentina/San_Luis -4:25:24 - LMT 1894 Oct 31 -4:16:48 - CMT 1920 May @@ -771,14 +772,14 @@ Zone America/La_Paz -4:32:36 - LMT 1890 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S # Decree 20,466 (1931-10-01) # Decree 21,896 (1932-01-10) -Rule Brazil 1931 only - Oct 3 11:00 1:00 S +Rule Brazil 1931 only - Oct 3 11:00 1:00 - Rule Brazil 1932 1933 - Apr 1 0:00 0 - -Rule Brazil 1932 only - Oct 3 0:00 1:00 S +Rule Brazil 1932 only - Oct 3 0:00 1:00 - # Decree 23,195 (1933-10-10) # revoked DST. # Decree 27,496 (1949-11-24) # Decree 27,998 (1950-04-13) -Rule Brazil 1949 1952 - Dec 1 0:00 1:00 S +Rule Brazil 1949 1952 - Dec 1 0:00 1:00 - Rule Brazil 1950 only - Apr 16 1:00 0 - Rule Brazil 1951 1952 - Apr 1 0:00 0 - # Decree 32,308 (1953-02-24) @@ -790,51 +791,51 @@ Rule Brazil 1953 only - Mar 1 0:00 0 - # in SP, RJ, GB, MG, ES, due to the prolongation of the drought. # Decree 53,071 (1963-12-03) # extended the above decree to all of the national territory on 12-09. -Rule Brazil 1963 only - Dec 9 0:00 1:00 S +Rule Brazil 1963 only - Dec 9 0:00 1:00 - # Decree 53,604 (1964-02-25) # extended summer time by one day to 1964-03-01 00:00 (start of school). Rule Brazil 1964 only - Mar 1 0:00 0 - # Decree 55,639 (1965-01-27) -Rule Brazil 1965 only - Jan 31 0:00 1:00 S +Rule Brazil 1965 only - Jan 31 0:00 1:00 - Rule Brazil 1965 only - Mar 31 0:00 0 - # Decree 57,303 (1965-11-22) -Rule Brazil 1965 only - Dec 1 0:00 1:00 S +Rule Brazil 1965 only - Dec 1 0:00 1:00 - # Decree 57,843 (1966-02-18) Rule Brazil 1966 1968 - Mar 1 0:00 0 - -Rule Brazil 1966 1967 - Nov 1 0:00 1:00 S +Rule Brazil 1966 1967 - Nov 1 0:00 1:00 - # Decree 63,429 (1968-10-15) # revoked DST. # Decree 91,698 (1985-09-27) -Rule Brazil 1985 only - Nov 2 0:00 1:00 S +Rule Brazil 1985 only - Nov 2 0:00 1:00 - # Decree 92,310 (1986-01-21) # Decree 92,463 (1986-03-13) Rule Brazil 1986 only - Mar 15 0:00 0 - # Decree 93,316 (1986-10-01) -Rule Brazil 1986 only - Oct 25 0:00 1:00 S +Rule Brazil 1986 only - Oct 25 0:00 1:00 - Rule Brazil 1987 only - Feb 14 0:00 0 - # Decree 94,922 (1987-09-22) -Rule Brazil 1987 only - Oct 25 0:00 1:00 S +Rule Brazil 1987 only - Oct 25 0:00 1:00 - Rule Brazil 1988 only - Feb 7 0:00 0 - # Decree 96,676 (1988-09-12) # except for the states of AC, AM, PA, RR, RO, and AP (then a territory) -Rule Brazil 1988 only - Oct 16 0:00 1:00 S +Rule Brazil 1988 only - Oct 16 0:00 1:00 - Rule Brazil 1989 only - Jan 29 0:00 0 - # Decree 98,077 (1989-08-21) # with the same exceptions -Rule Brazil 1989 only - Oct 15 0:00 1:00 S +Rule Brazil 1989 only - Oct 15 0:00 1:00 - Rule Brazil 1990 only - Feb 11 0:00 0 - # Decree 99,530 (1990-09-17) # adopted by RS, SC, PR, SP, RJ, ES, MG, GO, MS, DF. # Decree 99,629 (1990-10-19) adds BA, MT. -Rule Brazil 1990 only - Oct 21 0:00 1:00 S +Rule Brazil 1990 only - Oct 21 0:00 1:00 - Rule Brazil 1991 only - Feb 17 0:00 0 - # Unnumbered decree (1991-09-25) # adopted by RS, SC, PR, SP, RJ, ES, MG, BA, GO, MT, MS, DF. -Rule Brazil 1991 only - Oct 20 0:00 1:00 S +Rule Brazil 1991 only - Oct 20 0:00 1:00 - Rule Brazil 1992 only - Feb 9 0:00 0 - # Unnumbered decree (1992-10-16) # adopted by same states. -Rule Brazil 1992 only - Oct 25 0:00 1:00 S +Rule Brazil 1992 only - Oct 25 0:00 1:00 - Rule Brazil 1993 only - Jan 31 0:00 0 - # Decree 942 (1993-09-28) # adopted by same states, plus AM. @@ -844,12 +845,12 @@ Rule Brazil 1993 only - Jan 31 0:00 0 - # adopted by same states, plus MT and TO. # Decree 1,674 (1995-10-13) # adds AL, SE. -Rule Brazil 1993 1995 - Oct Sun>=11 0:00 1:00 S +Rule Brazil 1993 1995 - Oct Sun>=11 0:00 1:00 - Rule Brazil 1994 1995 - Feb Sun>=15 0:00 0 - Rule Brazil 1996 only - Feb 11 0:00 0 - # Decree 2,000 (1996-09-04) # adopted by same states, minus AL, SE. -Rule Brazil 1996 only - Oct 6 0:00 1:00 S +Rule Brazil 1996 only - Oct 6 0:00 1:00 - Rule Brazil 1997 only - Feb 16 0:00 0 - # From Daniel C. Sobral (1998-02-12): # In 1997, the DS began on October 6. The stated reason was that @@ -859,19 +860,19 @@ Rule Brazil 1997 only - Feb 16 0:00 0 - # to help dealing with the shortages of electric power. # # Decree 2,317 (1997-09-04), adopted by same states. -Rule Brazil 1997 only - Oct 6 0:00 1:00 S +Rule Brazil 1997 only - Oct 6 0:00 1:00 - # Decree 2,495 # (1998-02-10) Rule Brazil 1998 only - Mar 1 0:00 0 - # Decree 2,780 (1998-09-11) # adopted by the same states as before. -Rule Brazil 1998 only - Oct 11 0:00 1:00 S +Rule Brazil 1998 only - Oct 11 0:00 1:00 - Rule Brazil 1999 only - Feb 21 0:00 0 - # Decree 3,150 # (1999-08-23) adopted by same states. # Decree 3,188 (1999-09-30) # adds SE, AL, PB, PE, RN, CE, PI, MA and RR. -Rule Brazil 1999 only - Oct 3 0:00 1:00 S +Rule Brazil 1999 only - Oct 3 0:00 1:00 - Rule Brazil 2000 only - Feb 27 0:00 0 - # Decree 3,592 (2000-09-06) # adopted by the same states as before. @@ -881,34 +882,34 @@ Rule Brazil 2000 only - Feb 27 0:00 0 - # repeals DST in SE, AL, PB, RN, CE, PI and MA, effective 2000-10-22 00:00. # Decree 3,916 # (2001-09-13) reestablishes DST in AL, CE, MA, PB, PE, PI, RN, SE. -Rule Brazil 2000 2001 - Oct Sun>=8 0:00 1:00 S +Rule Brazil 2000 2001 - Oct Sun>=8 0:00 1:00 - Rule Brazil 2001 2006 - Feb Sun>=15 0:00 0 - # Decree 4,399 (2002-10-01) repeals DST in AL, CE, MA, PB, PE, PI, RN, SE. # 4,399 -Rule Brazil 2002 only - Nov 3 0:00 1:00 S +Rule Brazil 2002 only - Nov 3 0:00 1:00 - # Decree 4,844 (2003-09-24; corrected 2003-09-26) repeals DST in BA, MT, TO. # 4,844 -Rule Brazil 2003 only - Oct 19 0:00 1:00 S +Rule Brazil 2003 only - Oct 19 0:00 1:00 - # Decree 5,223 (2004-10-01) reestablishes DST in MT. # 5,223 -Rule Brazil 2004 only - Nov 2 0:00 1:00 S +Rule Brazil 2004 only - Nov 2 0:00 1:00 - # Decree 5,539 (2005-09-19), # adopted by the same states as before. -Rule Brazil 2005 only - Oct 16 0:00 1:00 S +Rule Brazil 2005 only - Oct 16 0:00 1:00 - # Decree 5,920 (2006-10-03), # adopted by the same states as before. -Rule Brazil 2006 only - Nov 5 0:00 1:00 S +Rule Brazil 2006 only - Nov 5 0:00 1:00 - Rule Brazil 2007 only - Feb 25 0:00 0 - # Decree 6,212 (2007-09-26), # adopted by the same states as before. -Rule Brazil 2007 only - Oct Sun>=8 0:00 1:00 S +Rule Brazil 2007 only - Oct Sun>=8 0:00 1:00 - # From Frederico A. C. Neves (2008-09-10): # According to this decree # http://www.planalto.gov.br/ccivil_03/_Ato2007-2010/2008/Decreto/D6558.htm # [t]he DST period in Brazil now on will be from the 3rd Oct Sunday to the # 3rd Feb Sunday. There is an exception on the return date when this is # the Carnival Sunday then the return date will be the next Sunday... -Rule Brazil 2008 2017 - Oct Sun>=15 0:00 1:00 S +Rule Brazil 2008 2017 - Oct Sun>=15 0:00 1:00 - Rule Brazil 2008 2011 - Feb Sun>=15 0:00 0 - # Decree 7,584 (2011-10-13) # added Bahia. @@ -926,7 +927,15 @@ Rule Brazil 2016 2022 - Feb Sun>=15 0:00 0 - # ... https://www.timeanddate.com/news/time/brazil-delays-dst-2018.html # From Steffen Thorsen (2017-12-20): # http://www.planalto.gov.br/ccivil_03/_ato2015-2018/2017/decreto/D9242.htm -Rule Brazil 2018 max - Nov Sun>=1 0:00 1:00 S +# +# From Fábio Gomes (2018-10-04): +# The Brazilian president just announced a new change on this year DST. +# It was scheduled to start on November 4th and it was changed to November 18th. +# From Rodrigo Brüning Wessler (2018-10-15): +# The Brazilian government just announced that the change in DST was +# canceled.... Maybe the president Michel Temer also woke up one hour +# earlier today. :) +Rule Brazil 2018 max - Nov Sun>=1 0:00 1:00 - Rule Brazil 2023 only - Feb Sun>=22 0:00 0 - Rule Brazil 2024 2025 - Feb Sun>=15 0:00 0 - Rule Brazil 2026 only - Feb Sun>=22 0:00 0 - @@ -1232,29 +1241,47 @@ Zone America/Rio_Branco -4:31:12 - LMT 1914 # they will switch from -03 to -04 one hour after Santiago does that day. # For now, assume that they will not revert. +# From Juan Correa (2018-08-13): +# As of moments ago, the Ministry of Energy in Chile has announced the new +# schema for DST. ... Announcement in video (in Spanish): +# https://twitter.com/MinEnergia/status/1029000399129374720 +# From Yonathan Dossow (2018-08-13): +# The video says "first Saturday of September", we all know it means Sunday at +# midnight. +# From Tim Parenti (2018-08-13): +# Translating the captions on the video at 0:44-0:55, "We want to announce as +# Government that from 2019, Winter Time will be increased to 5 months, between +# the first Saturday of April and the first Saturday of September." +# At 2:08-2:20, "The Magallanes region will maintain its current time, as +# decided by the citizens during 2017, but our Government will promote a +# regional dialogue table to gather their opinion on this matter." +# https://twitter.com/MinEnergia/status/1029009354001973248 +# "We will keep the new time policy unchanged for at least the next 4 years." +# So we extend the new rules on Saturdays at 24:00 mainland time indefinitely. + # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S -Rule Chile 1927 1931 - Sep 1 0:00 1:00 S +Rule Chile 1927 1931 - Sep 1 0:00 1:00 - Rule Chile 1928 1932 - Apr 1 0:00 0 - -Rule Chile 1968 only - Nov 3 4:00u 1:00 S +Rule Chile 1968 only - Nov 3 4:00u 1:00 - Rule Chile 1969 only - Mar 30 3:00u 0 - -Rule Chile 1969 only - Nov 23 4:00u 1:00 S +Rule Chile 1969 only - Nov 23 4:00u 1:00 - Rule Chile 1970 only - Mar 29 3:00u 0 - Rule Chile 1971 only - Mar 14 3:00u 0 - -Rule Chile 1970 1972 - Oct Sun>=9 4:00u 1:00 S +Rule Chile 1970 1972 - Oct Sun>=9 4:00u 1:00 - Rule Chile 1972 1986 - Mar Sun>=9 3:00u 0 - -Rule Chile 1973 only - Sep 30 4:00u 1:00 S -Rule Chile 1974 1987 - Oct Sun>=9 4:00u 1:00 S +Rule Chile 1973 only - Sep 30 4:00u 1:00 - +Rule Chile 1974 1987 - Oct Sun>=9 4:00u 1:00 - Rule Chile 1987 only - Apr 12 3:00u 0 - Rule Chile 1988 1990 - Mar Sun>=9 3:00u 0 - -Rule Chile 1988 1989 - Oct Sun>=9 4:00u 1:00 S -Rule Chile 1990 only - Sep 16 4:00u 1:00 S +Rule Chile 1988 1989 - Oct Sun>=9 4:00u 1:00 - +Rule Chile 1990 only - Sep 16 4:00u 1:00 - Rule Chile 1991 1996 - Mar Sun>=9 3:00u 0 - -Rule Chile 1991 1997 - Oct Sun>=9 4:00u 1:00 S +Rule Chile 1991 1997 - Oct Sun>=9 4:00u 1:00 - Rule Chile 1997 only - Mar 30 3:00u 0 - Rule Chile 1998 only - Mar Sun>=9 3:00u 0 - -Rule Chile 1998 only - Sep 27 4:00u 1:00 S +Rule Chile 1998 only - Sep 27 4:00u 1:00 - Rule Chile 1999 only - Apr 4 3:00u 0 - -Rule Chile 1999 2010 - Oct Sun>=9 4:00u 1:00 S +Rule Chile 1999 2010 - Oct Sun>=9 4:00u 1:00 - Rule Chile 2000 2007 - Mar Sun>=9 3:00u 0 - # N.B.: the end of March 29 in Chile is March 30 in Universal time, # which is used below in specifying the transition. @@ -1262,11 +1289,13 @@ Rule Chile 2008 only - Mar 30 3:00u 0 - Rule Chile 2009 only - Mar Sun>=9 3:00u 0 - Rule Chile 2010 only - Apr Sun>=1 3:00u 0 - Rule Chile 2011 only - May Sun>=2 3:00u 0 - -Rule Chile 2011 only - Aug Sun>=16 4:00u 1:00 S +Rule Chile 2011 only - Aug Sun>=16 4:00u 1:00 - Rule Chile 2012 2014 - Apr Sun>=23 3:00u 0 - -Rule Chile 2012 2014 - Sep Sun>=2 4:00u 1:00 S -Rule Chile 2016 max - May Sun>=9 3:00u 0 - -Rule Chile 2016 max - Aug Sun>=9 4:00u 1:00 S +Rule Chile 2012 2014 - Sep Sun>=2 4:00u 1:00 - +Rule Chile 2016 2018 - May Sun>=9 3:00u 0 - +Rule Chile 2016 2018 - Aug Sun>=9 4:00u 1:00 - +Rule Chile 2019 max - Apr Sun>=2 3:00u 0 - +Rule Chile 2019 max - Sep Sun>=2 4:00u 1:00 - # IATA SSIM anomalies: (1992-02) says 1992-03-14; # (1996-09) says 1998-03-08. Ignore these. # Zone NAME GMTOFF RULES FORMAT [UNTIL] @@ -1331,7 +1360,7 @@ Zone Antarctica/Palmer 0 - -00 1965 # "A variation of fifteen minutes in the public clocks of Bogota is not rare." # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S -Rule CO 1992 only - May 3 0:00 1:00 S +Rule CO 1992 only - May 3 0:00 1:00 - Rule CO 1993 only - Apr 4 0:00 0 - # Zone NAME GMTOFF RULES FORMAT [UNTIL] Zone America/Bogota -4:56:16 - LMT 1884 Mar 13 @@ -1391,7 +1420,7 @@ Link America/Curacao America/Kralendijk # Caribbean Netherlands # repeated. For now, assume transitions were at 00:00 local time country-wide. # # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S -Rule Ecuador 1992 only - Nov 28 0:00 1:00 S +Rule Ecuador 1992 only - Nov 28 0:00 1:00 - Rule Ecuador 1993 only - Feb 5 0:00 0 - # # Zone NAME GMTOFF RULES FORMAT [UNTIL] @@ -1481,22 +1510,22 @@ Zone Pacific/Galapagos -5:58:24 - LMT 1931 # Puerto Baquerizo Moreno # the maintainers of the database to inform them we're adopting # the same policy this year and suggest recommendations for future years. # -# For now we will assume permanent summer time for the Falklands +# For now we will assume permanent -03 for the Falklands # until advised differently (to apply for 2012 and beyond, after the 2011 # experiment was apparently successful.) # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S -Rule Falk 1937 1938 - Sep lastSun 0:00 1:00 S +Rule Falk 1937 1938 - Sep lastSun 0:00 1:00 - Rule Falk 1938 1942 - Mar Sun>=19 0:00 0 - -Rule Falk 1939 only - Oct 1 0:00 1:00 S -Rule Falk 1940 1942 - Sep lastSun 0:00 1:00 S +Rule Falk 1939 only - Oct 1 0:00 1:00 - +Rule Falk 1940 1942 - Sep lastSun 0:00 1:00 - Rule Falk 1943 only - Jan 1 0:00 0 - -Rule Falk 1983 only - Sep lastSun 0:00 1:00 S +Rule Falk 1983 only - Sep lastSun 0:00 1:00 - Rule Falk 1984 1985 - Apr lastSun 0:00 0 - -Rule Falk 1984 only - Sep 16 0:00 1:00 S -Rule Falk 1985 2000 - Sep Sun>=9 0:00 1:00 S +Rule Falk 1984 only - Sep 16 0:00 1:00 - +Rule Falk 1985 2000 - Sep Sun>=9 0:00 1:00 - Rule Falk 1986 2000 - Apr Sun>=16 0:00 0 - Rule Falk 2001 2010 - Apr Sun>=15 2:00 0 - -Rule Falk 2001 2010 - Sep Sun>=1 2:00 1:00 S +Rule Falk 2001 2010 - Sep Sun>=1 2:00 1:00 - # Zone NAME GMTOFF RULES FORMAT [UNTIL] Zone Atlantic/Stanley -3:51:24 - LMT 1890 -3:51:24 - SMT 1912 Mar 12 # Stanley Mean Time @@ -1531,16 +1560,16 @@ Zone America/Guyana -3:52:40 - LMT 1915 Mar # Georgetown # adjust their clocks at 0 hour of the given dates. # # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S -Rule Para 1975 1988 - Oct 1 0:00 1:00 S +Rule Para 1975 1988 - Oct 1 0:00 1:00 - Rule Para 1975 1978 - Mar 1 0:00 0 - Rule Para 1979 1991 - Apr 1 0:00 0 - -Rule Para 1989 only - Oct 22 0:00 1:00 S -Rule Para 1990 only - Oct 1 0:00 1:00 S -Rule Para 1991 only - Oct 6 0:00 1:00 S +Rule Para 1989 only - Oct 22 0:00 1:00 - +Rule Para 1990 only - Oct 1 0:00 1:00 - +Rule Para 1991 only - Oct 6 0:00 1:00 - Rule Para 1992 only - Mar 1 0:00 0 - -Rule Para 1992 only - Oct 5 0:00 1:00 S +Rule Para 1992 only - Oct 5 0:00 1:00 - Rule Para 1993 only - Mar 31 0:00 0 - -Rule Para 1993 1995 - Oct 1 0:00 1:00 S +Rule Para 1993 1995 - Oct 1 0:00 1:00 - Rule Para 1994 1995 - Feb lastSun 0:00 0 - Rule Para 1996 only - Mar 1 0:00 0 - # IATA SSIM (2000-02) says 1999-10-10; ignore this for now. @@ -1558,7 +1587,7 @@ Rule Para 1996 only - Mar 1 0:00 0 - # year, the time will change on the first Sunday of October; likewise, the # clock will be set back on the first Sunday of March. # -Rule Para 1996 2001 - Oct Sun>=1 0:00 1:00 S +Rule Para 1996 2001 - Oct Sun>=1 0:00 1:00 - # IATA SSIM (1997-09) says Mar 1; go with Shanks & Pottenger. Rule Para 1997 only - Feb lastSun 0:00 0 - # Shanks & Pottenger say 1999-02-28; IATA SSIM (1999-02) says 1999-02-27, but @@ -1569,7 +1598,7 @@ Rule Para 1998 2001 - Mar Sun>=1 0:00 0 - # dst method to be from the first Sunday in September to the first Sunday in # April. Rule Para 2002 2004 - Apr Sun>=1 0:00 0 - -Rule Para 2002 2003 - Sep Sun>=1 0:00 1:00 S +Rule Para 2002 2003 - Sep Sun>=1 0:00 1:00 - # # From Jesper Nørgaard Welen (2005-01-02): # There are several sources that claim that Paraguay made @@ -1578,7 +1607,7 @@ Rule Para 2002 2003 - Sep Sun>=1 0:00 1:00 S # Decree 1,867 (2004-03-05) # From Carlos Raúl Perasso via Jesper Nørgaard Welen (2006-10-13) # http://www.presidencia.gov.py/decretos/D1867.pdf -Rule Para 2004 2009 - Oct Sun>=15 0:00 1:00 S +Rule Para 2004 2009 - Oct Sun>=15 0:00 1:00 - Rule Para 2005 2009 - Mar Sun>=8 0:00 0 - # From Carlos Raúl Perasso (2010-02-18): # By decree number 3958 issued yesterday @@ -1591,7 +1620,7 @@ Rule Para 2005 2009 - Mar Sun>=8 0:00 0 - # and that on the first Sunday of the month of October, it is to be set # forward 60 minutes, in all the territory of the Paraguayan Republic. # ... -Rule Para 2010 max - Oct Sun>=1 0:00 1:00 S +Rule Para 2010 max - Oct Sun>=1 0:00 1:00 - Rule Para 2010 2012 - Apr Sun>=8 0:00 0 - # # From Steffen Thorsen (2013-03-07): @@ -1624,16 +1653,16 @@ Zone America/Asuncion -3:50:40 - LMT 1890 # Shanks & Pottenger don't have this transition. Assume 1986 was like 1987. # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S -Rule Peru 1938 only - Jan 1 0:00 1:00 S +Rule Peru 1938 only - Jan 1 0:00 1:00 - Rule Peru 1938 only - Apr 1 0:00 0 - -Rule Peru 1938 1939 - Sep lastSun 0:00 1:00 S +Rule Peru 1938 1939 - Sep lastSun 0:00 1:00 - Rule Peru 1939 1940 - Mar Sun>=24 0:00 0 - -Rule Peru 1986 1987 - Jan 1 0:00 1:00 S +Rule Peru 1986 1987 - Jan 1 0:00 1:00 - Rule Peru 1986 1987 - Apr 1 0:00 0 - -Rule Peru 1990 only - Jan 1 0:00 1:00 S +Rule Peru 1990 only - Jan 1 0:00 1:00 - Rule Peru 1990 only - Apr 1 0:00 0 - # IATA is ambiguous for 1993/1995; go with Shanks & Pottenger. -Rule Peru 1994 only - Jan 1 0:00 1:00 S +Rule Peru 1994 only - Jan 1 0:00 1:00 - Rule Peru 1994 only - Apr 1 0:00 0 - # Zone NAME GMTOFF RULES FORMAT [UNTIL] Zone America/Lima -5:08:12 - LMT 1890 @@ -1679,72 +1708,201 @@ Link America/Port_of_Spain America/Tortola # Virgin Islands (UK) # Uruguay # From Paul Eggert (1993-11-18): # Uruguay wins the prize for the strangest peacetime manipulation of the rules. -# From Shanks & Pottenger: +# +# From Tim Parenti (2018-02-20), per Jeremie Bonjour (2018-01-31) and Michael +# Deckers (2018-02-20): +# ... At least they kept good records... +# +# http://www.armada.mil.uy/ContenidosPDFs/sohma/web/almanaque/almanaque_2018.pdf#page=36 +# Page 36 of Almanaque 2018, published by the Oceanography, Hydrography, and +# Meteorology Service of the Uruguayan Navy, seems to give many transitions +# with greater clarity than we've had before. It directly references many laws +# and decrees which are, in turn, referenced below. They can be viewed in the +# public archives of the Diario Oficial (in Spanish) at +# http://www.impo.com.uy/diariooficial/ +# +# Ley No. 3920 of 1908-06-10 placed the determination of legal time under the +# auspices of the National Institute for the Prediction of Time. It is unclear +# exactly what offset was used during this period, though Ley No. 7200 of +# 1920-04-23 used the Observatory of the National Meteorological Institute in +# Montevideo (34° 54' 33" S, 56° 12' 45" W) as its reference meridian, +# retarding legal time by 15 minutes 9 seconds from 1920-04-30 24:00, +# resulting in UT-04. Assume the corresponding LMT of UT-03:44:51 (given on +# page 725 of the Proceedings of the Second Pan-American Scientific Congress, +# 1915-1916) was in use, and merely became official from 1908-06-10. +# https://www.impo.com.uy/diariooficial/1908/06/18/12 +# https://www.impo.com.uy/diariooficial/1920/04/27/9 +# +# Ley No. 7594 of 1923-06-28 specified legal time as Observatory time advanced +# by 44 minutes 51 seconds (UT-03) "from 30 September to 31 March", and by 14 +# minutes 51 seconds (UT-03:30) "the rest of the year"; a message from the +# National Council of Administration the same day, published directly below the +# law in the Diario Oficial, specified the first transition to be 1923-09-30 +# 24:00. This effectively established standard time at UT-03:30 with 30 +# minutes DST. Assume transitions at 24:00 on the specified days until Ley No. +# 7919 of 1926-03-05 ended this arrangement, repealing all "laws and other +# provisions which oppose" it, resulting in year-round UT-03:30; a Resolución +# of 1926-03-11 puts the final transition at 1926-03-31 24:00, the same as it +# would have been under the previous law. +# https://www.impo.com.uy/diariooficial/1923/07/02/2 +# https://www.impo.com.uy/diariooficial/1926/03/10/2 +# https://www.impo.com.uy/diariooficial/1926/03/18/2 +# # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S -# Whitman gives 1923 Oct 1; go with Shanks & Pottenger. -Rule Uruguay 1923 only - Oct 2 0:00 0:30 HS +Rule Uruguay 1923 1925 - Oct 1 0:00 0:30 - Rule Uruguay 1924 1926 - Apr 1 0:00 0 - -Rule Uruguay 1924 1925 - Oct 1 0:00 0:30 HS -Rule Uruguay 1933 1935 - Oct lastSun 0:00 0:30 HS -# Shanks & Pottenger give 1935 Apr 1 0:00 & 1936 Mar 30 0:00; go with Whitman. -Rule Uruguay 1934 1936 - Mar Sat>=25 23:30s 0 - -Rule Uruguay 1936 only - Nov 1 0:00 0:30 HS -Rule Uruguay 1937 1941 - Mar lastSun 0:00 0 - -# Whitman gives 1937 Oct 3; go with Shanks & Pottenger. -Rule Uruguay 1937 1940 - Oct lastSun 0:00 0:30 HS -# Whitman gives 1941 Oct 24 - 1942 Mar 27, 1942 Dec 14 - 1943 Apr 13, -# and 1943 Apr 13 "to present time"; go with Shanks & Pottenger. -Rule Uruguay 1941 only - Aug 1 0:00 0:30 HS -Rule Uruguay 1942 only - Jan 1 0:00 0 - -Rule Uruguay 1942 only - Dec 14 0:00 1:00 S +# From Tim Parenti (2018-02-15): +# http://www.impo.com.uy/diariooficial/1933/10/27/6 +# +# It appears Ley No. 9122 of 1933 was never published as such in the Diario +# Oficial, but instead appeared as Document 26 in the Diario on Friday +# 1933-10-27 as a decree made Monday 1933-10-23 and filed under the Ministry of +# National Defense. It reinstituted a DST of 30 minutes (to UT-03) "from the +# last Sunday of October...until the last Saturday of March." In accordance +# with this provision, the first transition was explicitly specified in Article +# 2 of the decree as Saturday 1933-10-28 at 24:00; that is, Sunday 1933-10-29 +# at 00:00. Assume transitions at 00:00 Sunday throughout. +# +# Departing from the matter-of-fact nature of previous timekeeping laws, the +# 1933 decree "consider[s] the advantages of...the advance of legal time": +# +# "Whereas: The measure adopted by almost all nations at the time of the last +# World War still persists in North America and Europe, precisely because of +# the economic, hygienic, and social advantages derived from such an +# emergency measure... +# +# Whereas: The advance of the legal time during the summer seasons, by +# displacing social activity near sunrise, favors the citizen populations +# and especially the society that creates and works..." +# +# It further specified that "necessary measures" be taken to ensure that +# "public spectacles finish, in general, before [01:00]." +Rule Uruguay 1933 1938 - Oct lastSun 0:00 0:30 - +Rule Uruguay 1934 1941 - Mar lastSat 24:00 0 - +# From Tim Parenti (2018-02-15): +# Most of the Rules below, and their contemporaneous Zone lines, have been +# updated simply to match the Almanaque 2018. Although the document does not +# list exact transition times, midnight transitions were already present in our +# data here for all transitions through 2004-09, and this is both consistent +# with prior transitions and verified in several decrees marked below between +# 1939-09 and 2004-09, wherein the relevant text was typically of the form: +# +# "From 0 hours on [date], the legal time of the entire Republic will be... +# +# In accordance with [the preceding], on [previous date] at 24 hours, all +# clocks throughout the Republic will be [advanced/retarded] by..." +# +# It is possible that there is greater specificity to be found for the Rules +# below, but it is buried in no fewer than 40 different decrees individually +# referenced by the Almanaque for the period from 1939-09 to 2014-09. +# Four-fifths of these were promulgated less than two weeks before taking +# effect; more than half within a week and none more than 5 weeks. Only the +# handful with comments below have been checked with any thoroughness. +Rule Uruguay 1939 only - Oct 1 0:00 0:30 - +Rule Uruguay 1940 only - Oct 27 0:00 0:30 - +# From Tim Parenti (2018-02-15): +# Decreto 1145 of the Ministry of National Defense, dated 1941-07-26, specified +# UT-03 from Friday 1941-08-01 00:00, citing an "urgent...need to save fuel". +# http://www.impo.com.uy/diariooficial/1941/08/04/1 +Rule Uruguay 1941 only - Aug 1 0:00 0:30 - +# From Tim Parenti (2018-02-15): +# Decreto 1866 of the Ministry of National Defense, dated 1942-12-09, specified +# further advancement (to UT-02:30) from Sunday 1942-12-13 24:00. Since clocks +# never went back to UT-03:30 thereafter, this is modeled as advancing standard +# time by 30 minutes to UT-03, while retaining 30 minutes of DST. +# http://www.impo.com.uy/diariooficial/1942/12/16/3 +Rule Uruguay 1942 only - Dec 14 0:00 0:30 - Rule Uruguay 1943 only - Mar 14 0:00 0 - -Rule Uruguay 1959 only - May 24 0:00 1:00 S +Rule Uruguay 1959 only - May 24 0:00 0:30 - Rule Uruguay 1959 only - Nov 15 0:00 0 - -Rule Uruguay 1960 only - Jan 17 0:00 1:00 S +Rule Uruguay 1960 only - Jan 17 0:00 1:00 - Rule Uruguay 1960 only - Mar 6 0:00 0 - -Rule Uruguay 1965 1967 - Apr Sun>=1 0:00 1:00 S +Rule Uruguay 1965 only - Apr 4 0:00 1:00 - Rule Uruguay 1965 only - Sep 26 0:00 0 - -Rule Uruguay 1966 1967 - Oct 31 0:00 0 - -Rule Uruguay 1968 1970 - May 27 0:00 0:30 HS -Rule Uruguay 1968 1970 - Dec 2 0:00 0 - -Rule Uruguay 1972 only - Apr 24 0:00 1:00 S -Rule Uruguay 1972 only - Aug 15 0:00 0 - -Rule Uruguay 1974 only - Mar 10 0:00 0:30 HS -Rule Uruguay 1974 only - Dec 22 0:00 1:00 S -Rule Uruguay 1976 only - Oct 1 0:00 0 - -Rule Uruguay 1977 only - Dec 4 0:00 1:00 S -Rule Uruguay 1978 only - Apr 1 0:00 0 - -Rule Uruguay 1979 only - Oct 1 0:00 1:00 S -Rule Uruguay 1980 only - May 1 0:00 0 - -Rule Uruguay 1987 only - Dec 14 0:00 1:00 S -Rule Uruguay 1988 only - Mar 14 0:00 0 - -Rule Uruguay 1988 only - Dec 11 0:00 1:00 S -Rule Uruguay 1989 only - Mar 12 0:00 0 - -Rule Uruguay 1989 only - Oct 29 0:00 1:00 S -# Shanks & Pottenger say no DST was observed in 1990/1 and 1991/2, -# and that 1992/3's DST was from 10-25 to 03-01. Go with IATA. -Rule Uruguay 1990 1992 - Mar Sun>=1 0:00 0 - -Rule Uruguay 1990 1991 - Oct Sun>=21 0:00 1:00 S -Rule Uruguay 1992 only - Oct 18 0:00 1:00 S +# From Tim Parenti (2018-02-15): +# Decreto 321/968 of 1968-05-25, citing emergency drought measures decreed the +# day before, brought clocks forward 30 minutes from Monday 1968-05-27 00:00. +# http://www.impo.com.uy/diariooficial/1968/05/30/5 +Rule Uruguay 1968 only - May 27 0:00 0:30 - +Rule Uruguay 1968 only - Dec 1 0:00 0 - +# From Tim Parenti (2018-02-15): +# Decreto 188/970 of 1970-04-23 instituted restrictions on electricity +# consumption "as a consequence of the current rainfall regime in the country". +# Articles 13 and 14 advanced clocks by an hour from Saturday 1970-04-25 00:00. +# http://www.impo.com.uy/diariooficial/1970/04/29/4 +Rule Uruguay 1970 only - Apr 25 0:00 1:00 - +Rule Uruguay 1970 only - Jun 14 0:00 0 - +Rule Uruguay 1972 only - Apr 23 0:00 1:00 - +Rule Uruguay 1972 only - Jul 16 0:00 0 - +# From Tim Parenti (2018-02-15): +# Decreto 29/974 of 1974-01-11, citing "the international rise in the price of +# oil", advanced clocks by 90 minutes (to UT-01:30). Decreto 163/974 of +# 1974-03-04 returned 60 of those minutes (to UT-02:30), and the remaining 30 +# minutes followed in Decreto 679/974 of 1974-08-29. +# http://www.impo.com.uy/diariooficial/1974/01/22/11 +# http://www.impo.com.uy/diariooficial/1974/03/14/3 +# http://www.impo.com.uy/diariooficial/1974/09/04/6 +Rule Uruguay 1974 only - Jan 13 0:00 1:30 - +Rule Uruguay 1974 only - Mar 10 0:00 0:30 - +Rule Uruguay 1974 only - Sep 1 0:00 0 - +Rule Uruguay 1974 only - Dec 22 0:00 1:00 - +Rule Uruguay 1975 only - Mar 30 0:00 0 - +Rule Uruguay 1976 only - Dec 19 0:00 1:00 - +Rule Uruguay 1977 only - Mar 6 0:00 0 - +Rule Uruguay 1977 only - Dec 4 0:00 1:00 - +Rule Uruguay 1978 1979 - Mar Sun>=1 0:00 0 - +Rule Uruguay 1978 only - Dec 17 0:00 1:00 - +Rule Uruguay 1979 only - Apr 29 0:00 1:00 - +Rule Uruguay 1980 only - Mar 16 0:00 0 - +# From Tim Parenti (2018-02-15): +# Decreto 725/987 of 1987-12-04 cited "better use of national tourist +# attractions" to advance clocks one hour from Monday 1987-12-14 00:00. +# http://www.impo.com.uy/diariooficial/1988/01/25/1 +Rule Uruguay 1987 only - Dec 14 0:00 1:00 - +Rule Uruguay 1988 only - Feb 28 0:00 0 - +Rule Uruguay 1988 only - Dec 11 0:00 1:00 - +Rule Uruguay 1989 only - Mar 5 0:00 0 - +Rule Uruguay 1989 only - Oct 29 0:00 1:00 - +Rule Uruguay 1990 only - Feb 25 0:00 0 - +# From Tim Parenti (2018-02-15), per Paul Eggert (1999-11-04): +# IATA agrees as below for 1990-10 through 1993-02. Per Almanaque 2018, the +# 1992/1993 season appears to be the first in over half a century where DST +# both began and ended pursuant to the same decree. +Rule Uruguay 1990 1991 - Oct Sun>=21 0:00 1:00 - +Rule Uruguay 1991 1992 - Mar Sun>=1 0:00 0 - +Rule Uruguay 1992 only - Oct 18 0:00 1:00 - Rule Uruguay 1993 only - Feb 28 0:00 0 - # From Eduardo Cota (2004-09-20): # The Uruguayan government has decreed a change in the local time.... -# http://www.presidencia.gub.uy/decretos/2004091502.htm -Rule Uruguay 2004 only - Sep 19 0:00 1:00 S +# From Tim Parenti (2018-02-15): +# Decreto 328/004 of 2004-09-15. +# http://www.impo.com.uy/diariooficial/2004/09/23/documentos.pdf#page=1 +Rule Uruguay 2004 only - Sep 19 0:00 1:00 - # From Steffen Thorsen (2005-03-11): # Uruguay's DST was scheduled to end on Sunday, 2005-03-13, but in order to # save energy ... it was postponed two weeks.... -# http://www.presidencia.gub.uy/_Web/noticias/2005/03/2005031005.htm +# From Tim Parenti (2018-02-15): +# This 2005 postponement is not in Almanaque 2018. Go with the contemporaneous +# reporting, which is confirmed by Decreto 107/005 of 2005-03-10 amending +# Decreto 328/004: +# http://www.impo.com.uy/diariooficial/2005/03/15/documentos.pdf#page=1 +# The original decree specified a transition of 2005-03-12 24:00, but the new +# one specified 2005-03-27 02:00. Rule Uruguay 2005 only - Mar 27 2:00 0 - # From Eduardo Cota (2005-09-27): -# http://www.presidencia.gub.uy/_Web/decretos/2005/09/CM%20119_09%2009%202005_00001.PDF -# This means that from 2005-10-09 at 02:00 local time, until 2006-03-12 at -# 02:00 local time, official time in Uruguay will be at GMT -2. -Rule Uruguay 2005 only - Oct 9 2:00 1:00 S -Rule Uruguay 2006 only - Mar 12 2:00 0 - -# From Jesper Nørgaard Welen (2006-09-06): -# http://www.presidencia.gub.uy/_web/decretos/2006/09/CM%20210_08%2006%202006_00001.PDF -# +# ...from 2005-10-09 at 02:00 local time, until 2006-03-12 at 02:00 local time, +# official time in Uruguay will be at GMT -2. +# From Tim Parenti (2018-02-15): +# Decreto 318/005 of 2005-09-19. +# http://www.impo.com.uy/diariooficial/2005/09/23/documentos.pdf#page=1 +Rule Uruguay 2005 only - Oct 9 2:00 1:00 - +Rule Uruguay 2006 2015 - Mar Sun>=8 2:00 0 - +# From Tim Parenti (2018-02-15), per Jesper Nørgaard Welen (2006-09-06): +# Decreto 311/006 of 2006-09-04 established regular DST from the first Sunday +# of October at 02:00 through the second Sunday of March at 02:00. Almanaque +# 2018 appears to have a few typoed dates through this period; ignore them. +# http://www.impo.com.uy/diariooficial/2006/09/08/documentos.pdf#page=1 +Rule Uruguay 2006 2014 - Oct Sun>=1 2:00 1:00 - # From Steffen Thorsen (2015-06-30): # ... it looks like they will not be using DST the coming summer: # http://www.elobservador.com.uy/gobierno-resolvio-que-no-habra-cambio-horario-verano-n656787 @@ -1754,17 +1912,19 @@ Rule Uruguay 2006 only - Mar 12 2:00 0 - # instead of out to dinner. # From Pablo Camargo (2015-07-13): # http://archivo.presidencia.gub.uy/sci/decretos/2015/06/cons_min_201.pdf -# [dated 2015-06-29; repeals Decree 311/006 dated 2006-09-04] -Rule Uruguay 2006 2014 - Oct Sun>=1 2:00 1:00 S -Rule Uruguay 2007 2015 - Mar Sun>=8 2:00 0 - +# From Tim Parenti (2018-02-15): +# Decreto 178/015 of 2015-06-29; repeals Decreto 311/006. # This Zone can be simplified once we assume zic %z. -Zone America/Montevideo -3:44:44 - LMT 1898 Jun 28 - -3:44:44 - MMT 1920 May 1 # Montevideo MT +Zone America/Montevideo -3:44:51 - LMT 1908 Jun 10 + -3:44:51 - MMT 1920 May 1 # Montevideo MT + -4:00 - -04 1923 Oct 1 -3:30 Uruguay -0330/-03 1942 Dec 14 + -3:00 Uruguay -03/-0230 1960 -3:00 Uruguay -03/-02 1968 - -3:00 Uruguay -03/-0230 1971 + -3:00 Uruguay -03/-0230 1970 -3:00 Uruguay -03/-02 1974 + -3:00 Uruguay -03/-0130 1974 Mar 10 -3:00 Uruguay -03/-0230 1974 Dec 22 -3:00 Uruguay -03/-02 diff --git a/contrib/tzdata/systemv b/contrib/tzdata/systemv index d9e2995756..24c8f64197 100644 --- a/contrib/tzdata/systemv +++ b/contrib/tzdata/systemv @@ -1,3 +1,5 @@ +# tzdb data for System V rules (this file is obsolete) + # This file is in the public domain, so clarified as of # 2009-05-17 by Arthur David Olson. diff --git a/contrib/tzdata/theory.html b/contrib/tzdata/theory.html dissimilarity index 86% index ff85f537b4..e9c9716cc6 100644 --- a/contrib/tzdata/theory.html +++ b/contrib/tzdata/theory.html @@ -1,1096 +1,1353 @@ - - - - Theory and pragmatics of the tz code and data - - - - - - -

Theory and pragmatics of the tz code and data

-

Outline

- - - -
-

Scope of the tz database

-

-The tz database attempts to record the history and predicted future of -all computer-based clocks that track civil time. To represent this -data, the world is partitioned into regions whose clocks all agree -about timestamps that occur after the somewhat-arbitrary cutoff point -of the POSIX Epoch (1970-01-01 00:00:00 UTC). For each such region, -the database records all known clock transitions, and labels the region -with a notable location. Although 1970 is a somewhat-arbitrary -cutoff, there are significant challenges to moving the cutoff earlier -even by a decade or two, due to the wide variety of local practices -before computer timekeeping became prevalent. -

- -

-Clock transitions before 1970 are recorded for each such location, -because most systems support timestamps before 1970 and could -misbehave if data entries were omitted for pre-1970 transitions. -However, the database is not designed for and does not suffice for -applications requiring accurate handling of all past times everywhere, -as it would take far too much effort and guesswork to record all -details of pre-1970 civil timekeeping. -Athough some information outside the scope of the database is -collected in a file backzone that is distributed along -with the database proper, this file is less reliable and does not -necessarily follow database guidelines. -

- -

-As described below, reference source code for using the tz database is -also available. The tz code is upwards compatible with POSIX, an -international standard for UNIX-like systems. As of this writing, the -current edition of POSIX is: - - The Open Group Base Specifications Issue 7, - IEEE Std 1003.1-2008, 2016 Edition. -

-
- - - -
-

Names of time zone rules

-

-Each of the database's time zone rules has a unique name. -Inexperienced users are not expected to select these names unaided. -Distributors should provide documentation and/or a simple selection -interface that explains the names; for one example, see the 'tzselect' -program in the tz code. The -Unicode Common Locale Data -Repository contains data that may be useful for other -selection interfaces. -

- -

-The time zone rule naming conventions attempt to strike a balance -among the following goals: -

-
    -
  • - Uniquely identify every region where clocks have agreed since 1970. - This is essential for the intended use: static clocks keeping local - civil time. -
    • -
  • - Indicate to experts where that region is. -
    • -
  • - Be robust in the presence of political changes. For example, names - of countries are ordinarily not used, to avoid incompatibilities - when countries change their name (e.g. Zaire→Congo) or when - locations change countries (e.g. Hong Kong from UK colony to - China). -
    • -
  • - Be portable to a wide variety of implementations. -
    • -
  • - Use a consistent naming conventions over the entire world. -
    • -
-

-Names normally have the -form AREA/LOCATION, -where AREA is the name of a continent or ocean, -and LOCATION is the name of a specific -location within that region. North and South America share the same -area, 'America'. Typical names are -'Africa/Cairo', 'America/New_York', and -'Pacific/Honolulu'. -

- -

-Here are the general rules used for choosing location names, -in decreasing order of importance: -

-
    -
  • - Use only valid POSIX file name components (i.e., the parts of - names other than '/'). Do not use the file name - components '.' and '..'. - Within a file name component, - use only ASCII letters, '.', - '-' and '_'. Do not use - digits, as that might create an ambiguity with POSIX - TZ strings. A file name component must not exceed 14 - characters or start with '-'. E.g., - prefer 'Brunei' to - 'Bandar_Seri_Begawan'. Exceptions: see - the discussion - of legacy names below. -
    • -
  • - A name must not be empty, or contain '//', or - start or end with '/'. -
    • -
  • - Do not use names that differ only in case. Although the reference - implementation is case-sensitive, some other implementations - are not, and they would mishandle names differing only in case. -
    • -
  • - If one name A is an initial prefix of another - name AB (ignoring case), then B - must not start with '/', as a - regular file cannot have - the same name as a directory in POSIX. For example, - 'America/New_York' precludes - 'America/New_York/Bronx'. -
    • -
  • - Uninhabited regions like the North Pole and Bouvet Island - do not need locations, since local time is not defined there. -
    • -
  • - There should typically be at least one name for each ISO 3166-1 - officially assigned two-letter code for an inhabited country - or territory. -
    • -
  • - If all the clocks in a region have agreed since 1970, - don't bother to include more than one location - even if subregions' clocks disagreed before 1970. - Otherwise these tables would become annoyingly large. -
    • -
  • - If a name is ambiguous, use a less ambiguous alternative; - e.g. many cities are named San José and Georgetown, so - prefer 'Costa_Rica' to 'San_Jose' and 'Guyana' to 'Georgetown'. -
    • -
  • - Keep locations compact. Use cities or small islands, not countries - or regions, so that any future time zone changes do not split - locations into different time zones. E.g. prefer - 'Paris' to 'France', since - France has had multiple time zones. -
    • -
  • - Use mainstream English spelling, e.g. prefer - 'Rome' to 'Roma', and prefer - 'Athens' to the Greek - 'Αθήνα' or the Romanized - 'Athína'. - The POSIX file name restrictions encourage this rule. -
    • -
  • - Use the most populous among locations in a zone, - e.g. prefer 'Shanghai' to - 'Beijing'. Among locations with - similar populations, pick the best-known location, - e.g. prefer 'Rome' to 'Milan'. -
    • -
  • - Use the singular form, e.g. prefer 'Canary' to 'Canaries'. -
    • -
  • - Omit common suffixes like '_Islands' and - '_City', unless that would lead to - ambiguity. E.g. prefer 'Cayman' to - 'Cayman_Islands' and - 'Guatemala' to - 'Guatemala_City', but prefer - 'Mexico_City' to 'Mexico' - because the country - of Mexico has several time zones. -
    • -
  • - Use '_' to represent a space. -
    • -
  • - Omit '.' from abbreviations in names, e.g. prefer - 'St_Helena' to 'St._Helena'. -
    • -
  • - Do not change established names if they only marginally - violate the above rules. For example, don't change - the existing name 'Rome' to - 'Milan' merely because - Milan's population has grown to be somewhat greater - than Rome's. -
    • -
  • - If a name is changed, put its old spelling in the - 'backward' file. - This means old spellings will continue to work. -
    • -
- -

-The file 'zone1970.tab' lists geographical locations used -to name time -zone rules. It is intended to be an exhaustive list of names for -geographic regions as described above; this is a subset of the names -in the data. Although a 'zone1970.tab' location's longitude -corresponds to its LMT offset with one hour for every 15° east -longitude, this relationship is not exact. -

- -

-Older versions of this package used a different naming scheme, -and these older names are still supported. -See the file 'backward' for most of these older names -(e.g., 'US/Eastern' instead of 'America/New_York'). -The other old-fashioned names still supported are -'WET', 'CET', 'MET', and 'EET' (see the file 'europe'). -

- -

-Older versions of this package defined legacy names that are -incompatible with the first rule of location names, but which are -still supported. These legacy names are mostly defined in the file -'etcetera'. Also, the file 'backward' defines the legacy names -'GMT0', 'GMT-0' and 'GMT+0', and the file 'northamerica' defines the -legacy names 'EST5EDT', 'CST6CDT', 'MST7MDT', and 'PST8PDT'. -

- -

-Excluding 'backward' should not affect the other data. If -'backward' is excluded, excluding 'etcetera' should not affect the -remaining data. -

- - -
-
-

Time zone abbreviations

-

-When this package is installed, it generates time zone abbreviations -like 'EST' to be compatible with human tradition and POSIX. -Here are the general rules used for choosing time zone abbreviations, -in decreasing order of importance: -

    -
  • - Use three to six characters that are ASCII alphanumerics or - '+' or '-'. - Previous editions of this database also used characters like - ' ' and '?', but these - characters have a special meaning to - the shell and cause commands like - 'set `date`' - to have unexpected effects. - Previous editions of this rule required upper-case letters, - but the Congressman who introduced Chamorro Standard Time - preferred "ChST", so lower-case letters are now allowed. - Also, POSIX from 2001 on relaxed the rule to allow - '-', '+', - and alphanumeric characters from the portable character set - in the current locale. In practice ASCII alphanumerics and - '+' and '-' are safe in all locales. - - In other words, in the C locale the POSIX extended regular - expression [-+[:alnum:]]{3,6} should match - the abbreviation. - This guarantees that all abbreviations could have been - specified by a POSIX TZ string. -
    • -
  • - Use abbreviations that are in common use among English-speakers, - e.g. 'EST' for Eastern Standard Time in North America. - We assume that applications translate them to other languages - as part of the normal localization process; for example, - a French application might translate 'EST' to 'HNE'. - -

    These abbreviations (for standard/daylight/etc. time) are: -ACST/ACDT Australian Central, -AST/ADT/APT/AWT/ADDT Atlantic, -AEST/AEDT Australian Eastern, -AHST/AHDT Alaska-Hawaii, -AKST/AKDT Alaska, -AWST/AWDT Australian Western, -BST/BDT Bering, -CAT/CAST Central Africa, -CET/CEST/CEMT Central European, -ChST Chamorro, -CST/CDT/CWT/CPT/CDDT Central [North America], -CST/CDT China, -GMT/BST/IST/BDST Greenwich, -EAT East Africa, -EST/EDT/EWT/EPT/EDDT Eastern [North America], -EET/EEST Eastern European, -GST Guam, -HST/HDT Hawaii, -HKT/HKST Hong Kong, -IST India, -IST/GMT Irish, -IST/IDT/IDDT Israel, -JST/JDT Japan, -KST/KDT Korea, -MET/MEST Middle European (a backward-compatibility alias for Central European), -MSK/MSD Moscow, -MST/MDT/MWT/MPT/MDDT Mountain, -NST/NDT/NWT/NPT/NDDT Newfoundland, -NST/NDT/NWT/NPT Nome, -NZMT/NZST New Zealand through 1945, -NZST/NZDT New Zealand 1946–present, -PKT/PKST Pakistan, -PST/PDT/PWT/PPT/PDDT Pacific, -SAST South Africa, -SST Samoa, -WAT/WAST West Africa, -WET/WEST/WEMT Western European, -WIB Waktu Indonesia Barat, -WIT Waktu Indonesia Timur, -WITA Waktu Indonesia Tengah, -YST/YDT/YWT/YPT/YDDT Yukon.

    -
    • -
  • - For zones whose times are taken from a city's longitude, use the -traditional xMT notation. The only abbreviation like this -in current use is 'GMT'. The others are for timestamps before 1960, -except that Monrovia Mean Time persisted until 1972. Typically, -numeric abbreviations (e.g., '-004430' for MMT) would -cause trouble here, as the numeric strings would exceed the POSIX length limit. - -

    These abbreviations are: -AMT Amsterdam, Asunción, Athens; -BMT Baghdad, Bangkok, Batavia, Bern, Bogotá, Bridgetown, Brussels, Bucharest; -CMT Calamarca, Caracas, Chisinau, Colón, Copenhagen, Córdoba; -DMT Dublin/Dunsink; -EMT Easter; -FFMT Fort-de-France; -FMT Funchal; -GMT Greenwich; -HMT Havana, Helsinki, Horta, Howrah; -IMT Irkutsk, Istanbul; -JMT Jerusalem; -KMT Kaunas, Kiev, Kingston; -LMT Lima, Lisbon, local, Luanda; -MMT Macassar, Madras, Malé, Managua, Minsk, Monrovia, Montevideo, Moratuwa, - Moscow; -PLMT Phù Liễn; -PMT Paramaribo, Paris, Perm, Pontianak, Prague; -PMMT Port Moresby; -QMT Quito; -RMT Rangoon, Riga, Rome; -SDMT Santo Domingo; -SJMT San José; -SMT Santiago, Simferopol, Singapore, Stanley; -TBMT Tbilisi; -TMT Tallinn, Tehran; -WMT Warsaw.

    - -

    A few abbreviations also follow the pattern that -GMT/BST established for time in the UK. They are: - -CMT/BST for Calamarca Mean Time and Bolivian Summer Time -1890–1932, DMT/IST for Dublin/Dunsink Mean Time and Irish Summer Time -1880–1916, MMT/MST/MDST for Moscow 1880–1919, and RMT/LST -for Riga Mean Time and Latvian Summer time 1880–1926. -An extra-special case is SET for Swedish Time (svensk -normaltid) 1879–1899, 3° west of the Stockholm -Observatory.

    -
    • -
  • - Use 'LMT' for local mean time of locations before the introduction - of standard time; see "Scope of the - tz database". -
    • -
  • - If there is no common English abbreviation, use numeric offsets like - -05 and +0830 that are - generated by zic's %z notation. -
    • -
  • - Use current abbreviations for older timestamps to avoid confusion. - For example, in 1910 a common English abbreviation for UT +01 - in central Europe was 'MEZ' (short for both "Middle European - Zone" and for "Mitteleuropäische Zeit" in German). Nowadays - 'CET' ("Central European Time") is more common in English, and - the database uses 'CET' even for circa-1910 timestamps as this - is less confusing for modern users and avoids the need for - determining when 'CET' supplanted 'MEZ' in common usage. -
    • -
  • - Use a consistent style in a zone's history. For example, if a zone's - history tends to use numeric abbreviations and a particular - entry could go either way, use a numeric abbreviation. -
    • -
  • - Use UT (with time zone abbreviation '-00') for - locations while uninhabited. The leading - '-' is a flag that the time - zone is in some sense undefined; this notation is - derived from Internet RFC 3339. -
    • -
-

-Application writers should note that these abbreviations are ambiguous -in practice: e.g., 'CST' means one thing in China and something else -in North America, and 'IST' can refer to time in India, Ireland or -Israel. To avoid ambiguity, use numeric UT offsets like -'-0600' instead of time zone abbreviations like 'CST'. -

-
- - -
-

Accuracy of the tz database

-

-The tz database is not authoritative, and it surely has errors. -Corrections are welcome and encouraged; see the file CONTRIBUTING. -Users requiring authoritative data should consult national standards -bodies and the references cited in the database's comments. -

- -

-Errors in the tz database arise from many sources: -

-
    -
  • - The tz database predicts future timestamps, and current predictions - will be incorrect after future governments change the rules. - For example, if today someone schedules a meeting for 13:00 next - October 1, Casablanca time, and tomorrow Morocco changes its - daylight saving rules, software can mess up after the rule change - if it blithely relies on conversions made before the change. -
    • -
  • - The pre-1970 entries in this database cover only a tiny sliver of how - clocks actually behaved; the vast majority of the necessary - information was lost or never recorded. Thousands more zones would - be needed if the tz database's scope were extended to cover even - just the known or guessed history of standard time; for example, - the current single entry for France would need to split into dozens - of entries, perhaps hundreds. And in most of the world even this - approach would be misleading due to widespread disagreement or - indifference about what times should be observed. In her 2015 book - The Global Transformation of Time, 1870-1950, Vanessa Ogle writes - "Outside of Europe and North America there was no system of time - zones at all, often not even a stable landscape of mean times, - prior to the middle decades of the twentieth century". See: - Timothy Shenk, Booked: - A Global History of Time. Dissent 2015-12-17. -
    • -
  • - Most of the pre-1970 data entries come from unreliable sources, often - astrology books that lack citations and whose compilers evidently - invented entries when the true facts were unknown, without - reporting which entries were known and which were invented. - These books often contradict each other or give implausible entries, - and on the rare occasions when they are checked they are - typically found to be incorrect. -
    • -
  • - For the UK the tz database relies on years of first-class work done by - Joseph Myers and others; see - "History of - legal time in Britain". - Other countries are not done nearly as well. -
    • -
  • - Sometimes, different people in the same city would maintain clocks - that differed significantly. Railway time was used by railroad - companies (which did not always agree with each other), - church-clock time was used for birth certificates, etc. - Often this was merely common practice, but sometimes it was set by law. - For example, from 1891 to 1911 the UT offset in France was legally - 0:09:21 outside train stations and 0:04:21 inside. -
    • -
  • - Although a named location in the tz database stands for the - containing region, its pre-1970 data entries are often accurate for - only a small subset of that region. For example, Europe/London - stands for the United Kingdom, but its pre-1847 times are valid - only for locations that have London's exact meridian, and its 1847 - transition to GMT is known to be valid only for the L&NW and the - Caledonian railways. -
    • -
  • - The tz database does not record the earliest time for which a zone's - data entries are thereafter valid for every location in the region. - For example, Europe/London is valid for all locations in its - region after GMT was made the standard time, but the date of - standardization (1880-08-02) is not in the tz database, other than - in commentary. For many zones the earliest time of validity is - unknown. -
    • -
  • - The tz database does not record a region's boundaries, and in many - cases the boundaries are not known. For example, the zone - America/Kentucky/Louisville represents a region around - the city of - Louisville, the boundaries of which are unclear. -
    • -
  • - Changes that are modeled as instantaneous transitions in the tz - database were often spread out over hours, days, or even decades. -
    • -
  • - Even if the time is specified by law, locations sometimes - deliberately flout the law. -
    • -
  • - Early timekeeping practices, even assuming perfect clocks, were - often not specified to the accuracy that the tz database requires. -
    • -
  • - Sometimes historical timekeeping was specified more precisely - than what the tz database can handle. For example, from 1909 to - 1937 Netherlands clocks were legally UT +00:19:32.13, but the tz - database cannot represent the fractional second. -
    • -
  • - Even when all the timestamp transitions recorded by the tz database - are correct, the tz rules that generate them may not faithfully - reflect the historical rules. For example, from 1922 until World - War II the UK moved clocks forward the day following the third - Saturday in April unless that was Easter, in which case it moved - clocks forward the previous Sunday. Because the tz database has no - way to specify Easter, these exceptional years are entered as - separate tz Rule lines, even though the legal rules did not change. -
    • -
  • - The tz database models pre-standard time using the proleptic Gregorian - calendar and local mean time (LMT), but many people used other - calendars and other timescales. For example, the Roman Empire used - the Julian calendar, and had 12 varying-length daytime hours with a - non-hour-based system at night. -
    • -
  • - Early clocks were less reliable, and data entries do not represent - clock error. -
    • -
  • - The tz database assumes Universal Time (UT) as an origin, even - though UT is not standardized for older timestamps. In the tz - database commentary, UT denotes a family of time standards that - includes Coordinated Universal Time (UTC) along with other variants - such as UT1 and GMT, with days starting at midnight. Although UT - equals UTC for modern timestamps, UTC was not defined until 1960, - so commentary uses the more-general abbreviation UT for timestamps - that might predate 1960. Since UT, UT1, etc. disagree slightly, - and since pre-1972 UTC seconds varied in length, interpretation of - older timestamps can be problematic when subsecond accuracy is - needed. -
    • -
  • - Civil time was not based on atomic time before 1972, and we don't - know the history of earth's rotation accurately enough to map SI - seconds to historical solar time to more than about one-hour - accuracy. See: Stephenson FR, Morrison LV, Hohenkerk CY. - Measurement - of the Earth's rotation: 720 BC to AD 2015. - Proc Royal Soc A. 2016 Dec 7;472:20160404. - Also see: Espenak F. Uncertainty - in Delta T (ΔT). -
    • -
  • - The relationship between POSIX time (that is, UTC but ignoring leap - seconds) and UTC is not agreed upon after 1972. Although the POSIX - clock officially stops during an inserted leap second, at least one - proposed standard has it jumping back a second instead; and in - practice POSIX clocks more typically either progress glacially during - a leap second, or are slightly slowed while near a leap second. -
    • -
  • - The tz database does not represent how uncertain its information is. - Ideally it would contain information about when data entries are - incomplete or dicey. Partial temporal knowledge is a field of - active research, though, and it's not clear how to apply it here. -
    • -
-

-In short, many, perhaps most, of the tz database's pre-1970 and future -timestamps are either wrong or misleading. Any attempt to pass the -tz database off as the definition of time should be unacceptable to -anybody who cares about the facts. In particular, the tz database's -LMT offsets should not be considered meaningful, and should not prompt -creation of zones merely because two locations differ in LMT or -transitioned to standard time at different dates. -

-
- - -
-

Time and date functions

-

-The tz code contains time and date functions that are upwards -compatible with those of POSIX. -

- -

-POSIX has the following properties and limitations. -

-
    -
  • -

    - In POSIX, time display in a process is controlled by the - environment variable TZ. Unfortunately, the POSIX TZ string takes - a form that is hard to describe and is error-prone in practice. - Also, POSIX TZ strings can't deal with other (for example, Israeli) - daylight saving time rules, or situations where more than two - time zone abbreviations are used in an area. -

    -

    - The POSIX TZ string takes the following form: -

    -

    - stdoffset[dst[offset][,date[/time],date[/time]]] -

    -

    - where: -

    -
    std and dst
    - are 3 or more characters specifying the standard - and daylight saving time (DST) zone names. - Starting with POSIX.1-2001, std - and dst may also be - in a quoted form like '<+09>'; this allows - "+" and "-" in the names. -
    -
    offset
    - is of the form - '[±]hh:[mm[:ss]]' - and specifies the offset west of UT. 'hh' - may be a single digit; 0≤hh≤24. - The default DST offset is one hour ahead of standard time. -
    -
    date[/time],date[/time]
    - specifies the beginning and end of DST. If this is absent, - the system supplies its own rules for DST, and these can - differ from year to year; typically US DST rules are used. -
    -
    time
    - takes the form - 'hh:[mm[:ss]]' - and defaults to 02:00. - This is the same format as the offset, except that a - leading '+' or '-' is not allowed. -
    -
    date
    - takes one of the following forms: -
    -
    Jn (1≤n≤365)
    - origin-1 day number not counting February 29 -
    -
    n (0≤n≤365)
    - origin-0 day number counting February 29 if present -
    -
    Mm.n.d (0[Sunday]≤d≤6[Saturday], 1≤n≤5, 1≤m≤12)
    - for the dth day of - week n of month m of the - year, where week 1 is the first week in which - day d appears, and '5' - stands for the last week in which - day d appears - (which may be either the 4th or 5th week). - Typically, this is the only useful form; - the n - and Jn forms are - rarely used. -
    -
    -
    -
    - Here is an example POSIX TZ string for New Zealand after 2007. - It says that standard time (NZST) is 12 hours ahead of UT, - and that daylight saving time (NZDT) is observed from September's - last Sunday at 02:00 until April's first Sunday at 03:00: - - 
    TZ='NZST-12NZDT,M9.5.0,M4.1.0/3'
    - - This POSIX TZ string is hard to remember, and mishandles some - timestamps before 2008. With this package you can use this - instead: - - 
    TZ='Pacific/Auckland'
    -
    • -
  • - POSIX does not define the exact meaning of TZ values like - "EST5EDT". - Typically the current US DST rules are used to interpret such values, - but this means that the US DST rules are compiled into each program - that does time conversion. This means that when US time conversion - rules change (as in the United States in 1987), all programs that - do time conversion must be recompiled to ensure proper results. -
    • -
  • - The TZ environment variable is process-global, which makes it hard - to write efficient, thread-safe applications that need access - to multiple time zones. -
    • -
  • - In POSIX, there's no tamper-proof way for a process to learn the - system's best idea of local wall clock. (This is important for - applications that an administrator wants used only at certain - times – - without regard to whether the user has fiddled the TZ environment - variable. While an administrator can "do everything in UT" to get - around the problem, doing so is inconvenient and precludes handling - daylight saving time shifts - as might be required to limit phone - calls to off-peak hours.) -
    • -
  • - POSIX provides no convenient and efficient way to determine the UT - offset and time zone abbreviation of arbitrary timestamps, - particularly for time zone settings that do not fit into the - POSIX model. -
    • -
  • - POSIX requires that systems ignore leap seconds. -
    • -
  • - The tz code attempts to support all the time_t - implementations allowed by POSIX. The time_t - type represents a nonnegative count of - seconds since 1970-01-01 00:00:00 UTC, ignoring leap seconds. - In practice, time_t is usually a signed 64- or - 32-bit integer; 32-bit signed time_t values stop - working after 2038-01-19 03:14:07 UTC, so - new implementations these days typically use a signed 64-bit integer. - Unsigned 32-bit integers are used on one or two platforms, - and 36-bit and 40-bit integers are also used occasionally. - Although earlier POSIX versions allowed time_t to be a - floating-point type, this was not supported by any practical - systems, and POSIX.1-2013 and the tz code both - require time_t - to be an integer type. -
    • -
-

-These are the extensions that have been made to the POSIX functions: -

-
    -
  • -

    - The TZ environment variable is used in generating the name of a file - from which time zone information is read (or is interpreted a la - POSIX); TZ is no longer constrained to be a three-letter time zone - name followed by a number of hours and an optional three-letter - daylight time zone name. The daylight saving time rules to be used - for a particular time zone are encoded in the time zone file; - the format of the file allows U.S., Australian, and other rules to be - encoded, and allows for situations where more than two time zone - abbreviations are used. -

    -

    - It was recognized that allowing the TZ environment variable to - take on values such as 'America/New_York' might - cause "old" programs - (that expect TZ to have a certain form) to operate incorrectly; - consideration was given to using some other environment variable - (for example, TIMEZONE) to hold the string used to generate the - time zone information file name. In the end, however, it was decided - to continue using TZ: it is widely used for time zone purposes; - separately maintaining both TZ and TIMEZONE seemed a nuisance; - and systems where "new" forms of TZ might cause problems can simply - use TZ values such as "EST5EDT" which can be used both by - "new" programs (a la POSIX) and "old" programs (as zone names and - offsets). -

    -
    • -
  • - The code supports platforms with a UT offset member - in struct tm, - e.g., tm_gmtoff. -
    • -
  • - The code supports platforms with a time zone abbreviation member in - struct tm, e.g., tm_zone. -
    • -
  • - Since the TZ environment variable can now be used to control time - conversion, the daylight - and timezone variables are no longer needed. - (These variables are defined and set by tzset; - however, their values will not be used - by localtime.) -
    • -
  • - Functions tzalloc, tzfree, - localtime_rz, and mktime_z for - more-efficient thread-safe applications that need to use - multiple time zones. The tzalloc - and tzfree functions allocate and free objects of - type timezone_t, and localtime_rz - and mktime_z are like localtime_r - and mktime with an extra - timezone_t argument. The functions were inspired - by NetBSD. -
    • -
  • - A function tzsetwall has been added to arrange - for the system's - best approximation to local wall clock time to be delivered by - subsequent calls to localtime. Source code for portable - applications that "must" run on local wall clock time should call - tzsetwall; if such code is moved to "old" systems that don't - provide tzsetwall, you won't be able to generate an executable program. - (These time zone functions also arrange for local wall clock time to be - used if tzset is called – directly or indirectly – - and there's no TZ - environment variable; portable applications should not, however, rely - on this behavior since it's not the way SVR2 systems behave.) -
    • -
  • - Negative time_t values are supported, on systems - where time_t is signed. -
    • -
  • - These functions can account for leap seconds, thanks to Bradley White. -
    • -
-

-Points of interest to folks with other systems: -

-
    -
  • - Code compatible with this package is already part of many platforms, - including GNU/Linux, Android, the BSDs, Chromium OS, Cygwin, AIX, iOS, - BlackBery 10, macOS, Microsoft Windows, OpenVMS, and Solaris. - On such hosts, the primary use of this package - is to update obsolete time zone rule tables. - To do this, you may need to compile the time zone compiler - 'zic' supplied with this package instead of using - the system 'zic', since the format - of zic's input is occasionally extended, and a - platform may still be shipping an older zic. -
    • -
  • - The UNIX Version 7 timezone function is not - present in this package; - it's impossible to reliably map timezone's arguments (a "minutes west - of GMT" value and a "daylight saving time in effect" flag) to a - time zone abbreviation, and we refuse to guess. - Programs that in the past used the timezone function may now examine - localtime(&clock)->tm_zone - (if TM_ZONE is defined) or - tzname[localtime(&clock)->tm_isdst] - (if HAVE_TZNAME is defined) - to learn the correct time zone abbreviation to use. -
    • -
  • - The 4.2BSD gettimeofday function is not used in - this package. - This formerly let users obtain the current UTC offset and DST flag, - but this functionality was removed in later versions of BSD. -
    • -
  • - In SVR2, time conversion fails for near-minimum or near-maximum - time_t values when doing conversions for places - that don't use UT. - This package takes care to do these conversions correctly. - A comment in the source code tells how to get compatibly wrong - results. -
    • -
-

-The functions that are conditionally compiled -if STD_INSPIRED is defined -should, at this point, be looked on primarily as food for thought. They are -not in any sense "standard compatible" – some are not, in fact, -specified in any standard. They do, however, represent responses of -various authors to -standardization proposals. -

- -

-Other time conversion proposals, in particular the one developed by folks at -Hewlett Packard, offer a wider selection of functions that provide capabilities -beyond those provided here. The absence of such functions from this package -is not meant to discourage the development, standardization, or use of such -functions. Rather, their absence reflects the decision to make this package -contain valid extensions to POSIX, to ensure its broad acceptability. If -more powerful time conversion functions can be standardized, so much the -better. -

-
- - -
-

Interface stability

-

-The tz code and data supply the following interfaces: -

-
    -
  • - A set of zone names as per "Names of time zone - rules" above. -
    • -
  • - Library functions described in "Time and date - functions" above. -
    • -
  • - The programs tzselect, zdump, - and zic, documented in their man pages. -
    • -
  • - The format of zic input files, documented in - the zic man page. -
    • -
  • - The format of zic output files, documented in - the tzfile man page. -
    • -
  • - The format of zone table files, documented in zone1970.tab. -
    • -
  • - The format of the country code file, documented in iso3166.tab. -
    • -
  • - The version number of the code and data, as the first line of - the text file 'version' in each release. -
    • -
-

-Interface changes in a release attempt to preserve compatibility with -recent releases. For example, tz data files typically do not rely on -recently-added zic features, so that users can run -older zic versions to process newer data -files. Sources for time zone and daylight -saving time data describes how -releases are tagged and distributed. -

- -

-Interfaces not listed above are less stable. For example, users -should not rely on particular UT offsets or abbreviations for -timestamps, as data entries are often based on guesswork and these -guesses may be corrected or improved. -

-
- - -
-

Calendrical issues

-

-Calendrical issues are a bit out of scope for a time zone database, -but they indicate the sort of problems that we would run into if we -extended the time zone database further into the past. An excellent -resource in this area is Nachum Dershowitz and Edward M. Reingold, -Calendrical -Calculations: Third Edition, Cambridge University Press (2008). -Other information and sources are given in the file 'calendars' -in the tz distribution. They sometimes disagree. -

-
- - -
-

Time and time zones on other planets

-

-Some people's work schedules use Mars time. Jet Propulsion Laboratory -(JPL) coordinators have kept Mars time on and off at least since 1997 -for the Mars Pathfinder mission. Some of their family members have -also adapted to Mars time. Dozens of special Mars watches were built -for JPL workers who kept Mars time during the Mars Exploration -Rovers mission (2004). These timepieces look like normal Seikos and -Citizens but use Mars seconds rather than terrestrial seconds. -

- -

-A Mars solar day is called a "sol" and has a mean period equal to -about 24 hours 39 minutes 35.244 seconds in terrestrial time. It is -divided into a conventional 24-hour clock, so each Mars second equals -about 1.02749125 terrestrial seconds. -

- -

-The prime meridian of Mars goes through the center of the crater -Airy-0, named in honor of the British astronomer who built the -Greenwich telescope that defines Earth's prime meridian. Mean solar -time on the Mars prime meridian is called Mars Coordinated Time (MTC). -

- -

-Each landed mission on Mars has adopted a different reference for -solar time keeping, so there is no real standard for Mars time zones. -For example, the Mars Exploration Rover project (2004) defined two -time zones "Local Solar Time A" and "Local Solar Time B" for its two -missions, each zone designed so that its time equals local true solar -time at approximately the middle of the nominal mission. Such a "time -zone" is not particularly suited for any application other than the -mission itself. -

- -

-Many calendars have been proposed for Mars, but none have achieved -wide acceptance. Astronomers often use Mars Sol Date (MSD) which is a -sequential count of Mars solar days elapsed since about 1873-12-29 -12:00 GMT. -

- -

-In our solar system, Mars is the planet with time and calendar most -like Earth's. On other planets, Sun-based time and calendars would -work quite differently. For example, although Mercury's sidereal -rotation period is 58.646 Earth days, Mercury revolves around the Sun -so rapidly that an observer on Mercury's equator would see a sunrise -only every 175.97 Earth days, i.e., a Mercury year is 0.5 of a Mercury -day. Venus is more complicated, partly because its rotation is -slightly retrograde: its year is 1.92 of its days. Gas giants like -Jupiter are trickier still, as their polar and equatorial regions -rotate at different rates, so that the length of a day depends on -latitude. This effect is most pronounced on Neptune, where the day is -about 12 hours at the poles and 18 hours at the equator. -

- -

-Although the tz database does not support time on other planets, it is -documented here in the hopes that support will be added eventually. -

- -

-Sources: -

- -
- -
-
-This file is in the public domain, so clarified as of 2009-05-17 by -Arthur David Olson. -
- - + + + + Theory and pragmatics of the tz code and data + + + + + +

Theory and pragmatics of the tz code and data

+

Outline

+ + +
+

Scope of the tz database

+

+The tz +database attempts to record the history and predicted future of +all computer-based clocks that track civil time. +It organizes time zone and daylight saving time +data by partitioning the world into timezones +whose clocks all agree about timestamps that occur after the POSIX Epoch +(1970-01-01 00:00:00 UTC). +The database labels each timezone with a notable location and +records all known clock transitions for that location. +Although 1970 is a somewhat-arbitrary cutoff, there are significant +challenges to moving the cutoff earlier even by a decade or two, due +to the wide variety of local practices before computer timekeeping +became prevalent. +

+ +

+Each timezone typically corresponds to a geographical region that is +smaller than a traditional time zone, because clocks in a timezone +all agree after 1970 whereas a traditional time zone merely +specifies current standard time. For example, applications that deal +with current and future timestamps in the traditional North +American mountain time zone can choose from the timezones +America/Denver which observes US-style daylight saving +time, America/Mazatlan which observes Mexican-style DST, +and America/Phoenix which does not observe DST. +Applications that also deal with past timestamps in the mountain time +zone can choose from over a dozen timezones, such as +America/Boise, America/Edmonton, and +America/Hermosillo, each of which currently uses mountain +time but differs from other timezones for some timestamps after 1970. +

+ +

+Clock transitions before 1970 are recorded for each timezone, +because most systems support timestamps before 1970 and could +misbehave if data entries were omitted for pre-1970 transitions. +However, the database is not designed for and does not suffice for +applications requiring accurate handling of all past times everywhere, +as it would take far too much effort and guesswork to record all +details of pre-1970 civil timekeeping. +Although some information outside the scope of the database is +collected in a file backzone that is distributed along +with the database proper, this file is less reliable and does not +necessarily follow database guidelines. +

+ +

+As described below, reference source code for using the +tz database is also available. +The tz code is upwards compatible with POSIX, an international +standard for UNIX-like systems. +As of this writing, the current edition of POSIX is: The Open +Group Base Specifications Issue 7, IEEE Std 1003.1-2017, 2018 +Edition. +Because the database's scope encompasses real-world changes to civil +timekeeping, its model for describing time is more complex than the +standard and daylight saving times supported by POSIX. +A tz timezone corresponds to a ruleset that can +have more than two changes per year, these changes need not merely +flip back and forth between two alternatives, and the rules themselves +can change at times. +Whether and when a timezone changes its +clock, and even the timezone's notional base offset from UTC, are variable. +It does not always make sense to talk about a timezone's +"base offset", which is not necessarily a single number. +

+ +
+ +
+

Names of timezones

+

+Each timezone has a unique name. +Inexperienced users are not expected to select these names unaided. +Distributors should provide documentation and/or a simple selection +interface that explains each name via a map or via descriptive text like +"Ruthenia" instead of the timezone name "Europe/Uzhgorod". +If geolocation information is available, a selection interface can +locate the user on a timezone map or prioritize names that are +geographically close. For an example selection interface, see the +tzselect program in the tz code. +The Unicode Common Locale Data +Repository contains data that may be useful for other selection +interfaces; it maps timezone names like Europe/Uzhgorod +to CLDR names like uauzh which are in turn mapped to +locale-dependent strings like "Uzhhorod", "Ungvár", "Ужгород", and +"乌日哥罗德". +

+ +

+The naming conventions attempt to strike a balance +among the following goals: +

+ +
    +
  • + Uniquely identify every timezone where clocks have agreed since 1970. + This is essential for the intended use: static clocks keeping local + civil time. +
    • +
  • + Indicate to experts where the timezone's clocks typically are. +
    • +
  • + Be robust in the presence of political changes. + For example, names of countries are ordinarily not used, to avoid + incompatibilities when countries change their name (e.g., + Zaire→Congo) or when locations change countries (e.g., Hong + Kong from UK colony to China). +
    • +
  • + Be portable to a wide variety of implementations. +
    • +
  • + Use a consistent naming conventions over the entire world. +
    • +
+ +

+Names normally have the form +AREA/LOCATION, where +AREA is a continent or ocean, and +LOCATION is a specific location within the area. +North and South America share the same area, 'America'. +Typical names are 'Africa/Cairo', +'America/New_York', and 'Pacific/Honolulu'. +Some names are further qualified to help avoid confusion; for example, +'America/Indiana/Petersburg' distinguishes Petersburg, +Indiana from other Petersburgs in America. +

+ +

+Here are the general guidelines used for +choosing timezone names, +in decreasing order of importance: +

+ +
    +
  • + Use only valid POSIX file name components (i.e., the parts of + names other than '/'). + Do not use the file name components '.' and + '..'. + Within a file name component, use only ASCII letters, + '.', '-' and '_'. + Do not use digits, as that might create an ambiguity with POSIX + TZ strings. + A file name component must not exceed 14 characters or start with + '-'. + E.g., prefer Asia/Brunei to + Asia/Bandar_Seri_Begawan. + Exceptions: see the discussion of legacy names below. +
    • +
  • + A name must not be empty, or contain '//', or + start or end with '/'. +
    • +
  • + Do not use names that differ only in case. + Although the reference implementation is case-sensitive, some + other implementations are not, and they would mishandle names + differing only in case. +
    • +
  • + If one name A is an initial prefix of another + name AB (ignoring case), then B must not + start with '/', as a regular file cannot have the + same name as a directory in POSIX. + For example, America/New_York precludes + America/New_York/Bronx. +
    • +
  • + Uninhabited regions like the North Pole and Bouvet Island + do not need locations, since local time is not defined there. +
    • +
  • + There should typically be at least one name for each ISO + 3166-1 officially assigned two-letter code for an inhabited + country or territory. +
    • +
  • + If all the clocks in a timezone have agreed since 1970, + do not bother to include more than one timezone + even if some of the clocks disagreed before 1970. + Otherwise these tables would become annoyingly large. +
    • +
  • + If a name is ambiguous, use a less ambiguous alternative; + e.g., many cities are named San José and Georgetown, so + prefer America/Costa_Rica to + America/San_Jose and America/Guyana + to America/Georgetown. +
    • +
  • + Keep locations compact. + Use cities or small islands, not countries or regions, so that any + future changes do not split individual locations into different + timezones. + E.g., prefer Europe/Paris to Europe/France, + since + France + has had multiple time zones. +
    • +
  • + Use mainstream English spelling, e.g., prefer + Europe/Rome to Europa/Roma, and + prefer Europe/Athens to the Greek + Ευρώπη/Αθήνα or the Romanized + Evrópi/Athína. + The POSIX file name restrictions encourage this guideline. +
    • +
  • + Use the most populous among locations in a region, + e.g., prefer Asia/Shanghai to + Asia/Beijing. + Among locations with similar populations, pick the best-known + location, e.g., prefer Europe/Rome to + Europe/Milan. +
    • +
  • + Use the singular form, e.g., prefer Atlantic/Canary to + Atlantic/Canaries. +
    • +
  • + Omit common suffixes like '_Islands' and + '_City', unless that would lead to ambiguity. + E.g., prefer America/Cayman to + America/Cayman_Islands and + America/Guatemala to + America/Guatemala_City, but prefer + America/Mexico_City to + America/Mexico + because the + country of Mexico has several time zones. +
    • +
  • + Use '_' to represent a space. +
    • +
  • + Omit '.' from abbreviations in names. + E.g., prefer Atlantic/St_Helena to + Atlantic/St._Helena. +
    • +
  • + Do not change established names if they only marginally violate + the above guidelines. + For example, do not change the existing name Europe/Rome to + Europe/Milan merely because Milan's population has grown + to be somewhat greater than Rome's. +
    • +
  • + If a name is changed, put its old spelling in the + 'backward' file. + This means old spellings will continue to work. +
    • +
+ +

+The file 'zone1970.tab' lists geographical locations used +to name timezones. +It is intended to be an exhaustive list of names for geographic +regions as described above; this is a subset of the timezones in the data. +Although a 'zone1970.tab' location's +longitude +corresponds to +its local mean +time (LMT) offset with one hour for every 15° +east longitude, this relationship is not exact. +

+ +

+Older versions of this package used a different naming scheme, +and these older names are still supported. +See the file 'backward' for most of these older names +(e.g., 'US/Eastern' instead of 'America/New_York'). +The other old-fashioned names still supported are +'WET', 'CET', 'MET', and +'EET' (see the file 'europe'). +

+ +

+Older versions of this package defined legacy names that are +incompatible with the first guideline of location names, but which are +still supported. +These legacy names are mostly defined in the file +'etcetera'. +Also, the file 'backward' defines the legacy names +'GMT0', 'GMT-0' and 'GMT+0', +and the file 'northamerica' defines the legacy names +'EST5EDT', 'CST6CDT', +'MST7MDT', and 'PST8PDT'. +

+ +

+Excluding 'backward' should not affect the other data. +If 'backward' is excluded, excluding +'etcetera' should not affect the remaining data. +

+
+ +
+

Time zone abbreviations

+

+When this package is installed, it generates time zone abbreviations +like 'EST' to be compatible with human tradition and POSIX. +Here are the general guidelines used for choosing time zone abbreviations, +in decreasing order of importance: +

+ +
    +
  • + Use three to six characters that are ASCII alphanumerics or + '+' or '-'. + Previous editions of this database also used characters like + space and '?', but these characters have a + special meaning to the + UNIX shell + and cause commands like + 'set + `date`' + to have unexpected effects. + Previous editions of this guideline required upper-case letters, but the + Congressman who introduced + Chamorro + Standard Time preferred "ChST", so lower-case letters are now + allowed. + Also, POSIX from 2001 on relaxed the rule to allow '-', + '+', and alphanumeric characters from the portable + character set in the current locale. + In practice ASCII alphanumerics and '+' and + '-' are safe in all locales. + +

    + In other words, in the C locale the POSIX extended regular + expression [-+[:alnum:]]{3,6} should match the + abbreviation. + This guarantees that all abbreviations could have been specified by a + POSIX TZ string. +

    +
    • +
  • + Use abbreviations that are in common use among English-speakers, + e.g., 'EST' for Eastern Standard Time in North America. + We assume that applications translate them to other languages + as part of the normal localization process; for example, + a French application might translate 'EST' to 'HNE'. + +

    + These abbreviations (for standard/daylight/etc. time) are: + ACST/ACDT Australian Central, + AST/ADT/APT/AWT/ADDT Atlantic, + AEST/AEDT Australian Eastern, + AHST/AHDT Alaska-Hawaii, + AKST/AKDT Alaska, + AWST/AWDT Australian Western, + BST/BDT Bering, + CAT/CAST Central Africa, + CET/CEST/CEMT Central European, + ChST Chamorro, + CST/CDT/CWT/CPT/CDDT Central [North America], + CST/CDT China, + GMT/BST/IST/BDST Greenwich, + EAT East Africa, + EST/EDT/EWT/EPT/EDDT Eastern [North America], + EET/EEST Eastern European, + GST Guam, + HST/HDT/HWT/HPT Hawaii, + HKT/HKST Hong Kong, + IST India, + IST/GMT Irish, + IST/IDT/IDDT Israel, + JST/JDT Japan, + KST/KDT Korea, + MET/MEST Middle European (a backward-compatibility alias for + Central European), + MSK/MSD Moscow, + MST/MDT/MWT/MPT/MDDT Mountain, + NST/NDT/NWT/NPT/NDDT Newfoundland, + NST/NDT/NWT/NPT Nome, + NZMT/NZST New Zealand through 1945, + NZST/NZDT New Zealand 1946–present, + PKT/PKST Pakistan, + PST/PDT/PWT/PPT/PDDT Pacific, + PST/PDT Philippine, + SAST South Africa, + SST Samoa, + WAT/WAST West Africa, + WET/WEST/WEMT Western European, + WIB Waktu Indonesia Barat, + WIT Waktu Indonesia Timur, + WITA Waktu Indonesia Tengah, + YST/YDT/YWT/YPT/YDDT Yukon. +

    +
    • +
  • +

    + For times taken from a city's longitude, use the + traditional xMT notation. + The only abbreviation like this in current use is 'GMT'. + The others are for timestamps before 1960, + except that Monrovia Mean Time persisted until 1972. + Typically, numeric abbreviations (e.g., '-004430' for + MMT) would cause trouble here, as the numeric strings would exceed + the POSIX length limit. +

    + +

    + These abbreviations are: + AMT Amsterdam, Asunción, Athens; + BMT Baghdad, Bangkok, Batavia, Bern, Bogotá, Bridgetown, Brussels, + Bucharest; + CMT Calamarca, Caracas, Chisinau, Colón, Copenhagen, Córdoba; + DMT Dublin/Dunsink; + EMT Easter; + FFMT Fort-de-France; + FMT Funchal; + GMT Greenwich; + HMT Havana, Helsinki, Horta, Howrah; + IMT Irkutsk, Istanbul; + JMT Jerusalem; + KMT Kaunas, Kiev, Kingston; + LMT Lima, Lisbon, local, Luanda; + MMT Macassar, Madras, Malé, Managua, Minsk, Monrovia, Montevideo, + Moratuwa, Moscow; + PLMT Phù Liễn; + PMT Paramaribo, Paris, Perm, Pontianak, Prague; + PMMT Port Moresby; + QMT Quito; + RMT Rangoon, Riga, Rome; + SDMT Santo Domingo; + SJMT San José; + SMT Santiago, Simferopol, Singapore, Stanley; + TBMT Tbilisi; + TMT Tallinn, Tehran; + WMT Warsaw. +

    + +

    + A few abbreviations also follow the pattern that + GMT/BST established for time in the UK. + They are: + CMT/BST for Calamarca Mean Time and Bolivian Summer Time + 1890–1932, + DMT/IST for Dublin/Dunsink Mean Time and Irish Summer Time + 1880–1916, + MMT/MST/MDST for Moscow 1880–1919, and + RMT/LST for Riga Mean Time and Latvian Summer time 1880–1926. + An extra-special case is SET for Swedish Time (svensk + normaltid) 1879–1899, 3° west of the Stockholm + Observatory. +

    +
    • +
  • + Use 'LMT' for local mean time of locations before the + introduction of standard time; see "Scope of the + tz database". +
    • +
  • + If there is no common English abbreviation, use numeric offsets like + -05 and +0530 that are generated + by zic's %z notation. +
    • +
  • + Use current abbreviations for older timestamps to avoid confusion. + For example, in 1910 a common English abbreviation for time + in central Europe was 'MEZ' (short for both "Middle European + Zone" and for "Mitteleuropäische Zeit" in German). + Nowadays 'CET' ("Central European Time") is more common in + English, and the database uses 'CET' even for circa-1910 + timestamps as this is less confusing for modern users and avoids + the need for determining when 'CET' supplanted 'MEZ' in common + usage. +
    • +
  • + Use a consistent style in a timezone's history. + For example, if a history tends to use numeric + abbreviations and a particular entry could go either way, use a + numeric abbreviation. +
    • +
  • + Use + Universal Time + (UT) (with time zone abbreviation '-00') for + locations while uninhabited. + The leading '-' is a flag that the UT offset is in + some sense undefined; this notation is derived + from Internet + RFC 3339. +
    • +
+ +

+Application writers should note that these abbreviations are ambiguous +in practice: e.g., 'CST' means one thing in China and something else +in North America, and 'IST' can refer to time in India, Ireland or +Israel. +To avoid ambiguity, use numeric UT offsets like +'-0600' instead of time zone abbreviations like 'CST'. +

+
+ +
+

Accuracy of the tz database

+

+The tz database is not authoritative, and it +surely has errors. +Corrections are welcome and encouraged; see the file CONTRIBUTING. +Users requiring authoritative data should consult national standards +bodies and the references cited in the database's comments. +

+ +

+Errors in the tz database arise from many sources: +

+ +
    +
  • + The tz database predicts future + timestamps, and current predictions + will be incorrect after future governments change the rules. + For example, if today someone schedules a meeting for 13:00 next + October 1, Casablanca time, and tomorrow Morocco changes its + daylight saving rules, software can mess up after the rule change + if it blithely relies on conversions made before the change. +
    • +
  • + The pre-1970 entries in this database cover only a tiny sliver of how + clocks actually behaved; the vast majority of the necessary + information was lost or never recorded. + Thousands more timezones would be needed if + the tz database's scope were extended to + cover even just the known or guessed history of standard time; for + example, the current single entry for France would need to split + into dozens of entries, perhaps hundreds. + And in most of the world even this approach would be misleading + due to widespread disagreement or indifference about what times + should be observed. + In her 2015 book + The + Global Transformation of Time, 1870–1950, + Vanessa Ogle writes + "Outside of Europe and North America there was no system of time + zones at all, often not even a stable landscape of mean times, + prior to the middle decades of the twentieth century". + See: Timothy Shenk, Booked: + A Global History of Time. Dissent 2015-12-17. +
    • +
  • + Most of the pre-1970 data entries come from unreliable sources, often + astrology books that lack citations and whose compilers evidently + invented entries when the true facts were unknown, without + reporting which entries were known and which were invented. + These books often contradict each other or give implausible entries, + and on the rare occasions when they are checked they are + typically found to be incorrect. +
    • +
  • + For the UK the tz database relies on + years of first-class work done by + Joseph Myers and others; see + "History of + legal time in Britain". + Other countries are not done nearly as well. +
    • +
  • + Sometimes, different people in the same city maintain clocks + that differ significantly. + Historically, railway time was used by railroad companies (which + did not always + agree with each other), church-clock time was used for birth + certificates, etc. + More recently, competing political groups might disagree about + clock settings. Often this is merely common practice, but + sometimes it is set by law. + For example, from 1891 to 1911 the UT offset in France + was legally UT +00:09:21 outside train stations and + UT +00:04:21 inside. Other examples include + Chillicothe in 1920, Palm Springs in 1946/7, and Jerusalem and + Ürümqi to this day. +
    • +
  • + Although a named location in the tz + database stands for the containing region, its pre-1970 data + entries are often accurate for only a small subset of that region. + For example, Europe/London stands for the United + Kingdom, but its pre-1847 times are valid only for locations that + have London's exact meridian, and its 1847 transition + to GMT is known to be valid only for the L&NW and + the Caledonian railways. +
    • +
  • + The tz database does not record the + earliest time for which a timezone's + data entries are thereafter valid for every location in the region. + For example, Europe/London is valid for all locations + in its region after GMT was made the standard time, + but the date of standardization (1880-08-02) is not in the + tz database, other than in commentary. + For many timezones the earliest time of + validity is unknown. +
    • +
  • + The tz database does not record a + region's boundaries, and in many cases the boundaries are not known. + For example, the timezone + America/Kentucky/Louisville represents a region + around the city of Louisville, the boundaries of which are + unclear. +
    • +
  • + Changes that are modeled as instantaneous transitions in the + tz + database were often spread out over hours, days, or even decades. +
    • +
  • + Even if the time is specified by law, locations sometimes + deliberately flout the law. +
    • +
  • + Early timekeeping practices, even assuming perfect clocks, were + often not specified to the accuracy that the + tz database requires. +
    • +
  • + Sometimes historical timekeeping was specified more precisely + than what the tz code can handle. + For example, from 1909 to 1937 Netherlands clocks were legally Amsterdam Mean + Time (estimated to be UT + +00:19:32.13), but the tz + code cannot represent the fractional second. + In practice these old specifications were rarely if ever + implemented to subsecond precision. +
    • +
  • + Even when all the timestamp transitions recorded by the + tz database are correct, the + tz rules that generate them may not + faithfully reflect the historical rules. + For example, from 1922 until World War II the UK moved clocks + forward the day following the third Saturday in April unless that + was Easter, in which case it moved clocks forward the previous + Sunday. + Because the tz database has no + way to specify Easter, these exceptional years are entered as + separate tz Rule lines, even though the + legal rules did not change. + When transitions are known but the historical rules behind them are not, + the database contains Zone and Rule + entries that are intended to represent only the generated + transitions, not any underlying historical rules; however, this + intent is recorded at best only in commentary. +
    • +
  • + The tz database models time + using the proleptic + Gregorian calendar with days containing 24 equal-length hours + numbered 00 through 23, except when clock transitions occur. + Pre-standard time is modeled as local mean time. + However, historically many people used other calendars and other timescales. + For example, the Roman Empire used + the Julian + calendar, + and Roman + timekeeping had twelve varying-length daytime hours with a + non-hour-based system at night. + And even today, some local practices diverge from the Gregorian + calendar with 24-hour days. These divergences range from + relatively minor, such as Japanese bars giving times like "24:30" for the + wee hours of the morning, to more-significant differences such as the + east African practice of starting the day at dawn, renumbering + the Western 06:00 to be 12:00. These practices are largely outside + the scope of the tz code and data, which + provide only limited support for date and time localization + such as that required by POSIX. If DST is not used a different time zone + can often do the trick; for example, in Kenya a TZ setting + like <-03>3 or America/Cayenne starts + the day six hours later than Africa/Nairobi does. +
    • +
  • + Early clocks were less reliable, and data entries do not represent + clock error. +
    • +
  • + The tz database assumes Universal Time + (UT) as an origin, even though UT is not + standardized for older timestamps. + In the tz database commentary, + UT denotes a family of time standards that includes + Coordinated Universal Time (UTC) along with other + variants such as UT1 and GMT, + with days starting at midnight. + Although UT equals UTC for modern + timestamps, UTC was not defined until 1960, so + commentary uses the more-general abbreviation UT for + timestamps that might predate 1960. + Since UT, UT1, etc. disagree slightly, + and since pre-1972 UTC seconds varied in length, + interpretation of older timestamps can be problematic when + subsecond accuracy is needed. +
    • +
  • + Civil time was not based on atomic time before 1972, and we do not + know the history of + earth's + rotation accurately enough to map SI seconds to + historical solar time + to more than about one-hour accuracy. + See: Stephenson FR, Morrison LV, Hohenkerk CY. + Measurement of + the Earth's rotation: 720 BC to AD 2015. + Proc Royal Soc A. 2016 Dec 7;472:20160404. + Also see: Espenak F. Uncertainty + in Delta T (ΔT). +
    • +
  • + The relationship between POSIX time (that is, UTC but + ignoring leap + seconds) and UTC is not agreed upon after 1972. + Although the POSIX + clock officially stops during an inserted leap second, at least one + proposed standard has it jumping back a second instead; and in + practice POSIX clocks more typically either progress glacially during + a leap second, or are slightly slowed while near a leap second. +
    • +
  • + The tz database does not represent how + uncertain its information is. + Ideally it would contain information about when data entries are + incomplete or dicey. + Partial temporal knowledge is a field of active research, though, + and it is not clear how to apply it here. +
    • +
+ +

+In short, many, perhaps most, of the tz +database's pre-1970 and future timestamps are either wrong or +misleading. +Any attempt to pass the +tz database off as the definition of time +should be unacceptable to anybody who cares about the facts. +In particular, the tz database's +LMT offsets should not be considered meaningful, and +should not prompt creation of timezones +merely because two locations +differ in LMT or transitioned to standard time at +different dates. +

+
+ +
+

Time and date functions

+

+The tz code contains time and date functions +that are upwards compatible with those of POSIX. +Code compatible with this package is already +part of many platforms, where the +primary use of this package is to update obsolete time-related files. +To do this, you may need to compile the time zone compiler +'zic' supplied with this package instead of using the +system 'zic', since the format of zic's +input is occasionally extended, and a platform may still be shipping +an older zic. +

+ +

POSIX properties and limitations

+
    +
  • +

    + In POSIX, time display in a process is controlled by the + environment variable TZ. + Unfortunately, the POSIX + TZ string takes a form that is hard to describe and + is error-prone in practice. + Also, POSIX TZ strings cannot deal with daylight + saving time rules not based on the Gregorian calendar (as in + Iran), or with situations where more than two time zone + abbreviations or UT offsets are used in an area. +

    + +

    + The POSIX TZ string takes the following form: +

    + +

    + stdoffset[dst[offset][,date[/time],date[/time]]] +

    + +

    + where: +

    + +
    +
    std and dst
    + are 3 or more characters specifying the standard + and daylight saving time (DST) zone abbreviations. + Starting with POSIX.1-2001, std and dst + may also be in a quoted form like '<+09>'; + this allows "+" and "-" in the names. +
    +
    offset
    + is of the form + '[±]hh:[mm[:ss]]' + and specifies the offset west of UT. + 'hh' may be a single digit; + 0≤hh≤24. + The default DST offset is one hour ahead of + standard time. +
    +
    date[/time],date[/time]
    + specifies the beginning and end of DST. + If this is absent, the system supplies its own ruleset + for DST, and its rules can differ from year to year; + typically US DST rules are used. +
    +
    time
    + takes the form + 'hh:[mm[:ss]]' + and defaults to 02:00. + This is the same format as the offset, except that a + leading '+' or '-' is not allowed. +
    +
    date
    + takes one of the following forms: +
    +
    Jn (1≤n≤365)
    + origin-1 day number not counting February 29 +
    +
    n (0≤n≤365)
    + origin-0 day number counting February 29 if present +
    +
    Mm.n.d + (0[Sunday]≤d≤6[Saturday], 1≤n≤5, + 1≤m≤12)
    + for the dth day of week n of + month m of the year, where week 1 is the first + week in which day d appears, and + '5' stands for the last week in which + day d appears (which may be either the 4th or + 5th week). + Typically, this is the only useful form; the n + and Jn forms are rarely used. +
    +
    +
    +
    + +

    + Here is an example POSIX TZ string for New + Zealand after 2007. + It says that standard time (NZST) is 12 hours ahead + of UT, and that daylight saving time + (NZDT) is observed from September's last Sunday at + 02:00 until April's first Sunday at 03:00: +

    + + 
    TZ='NZST-12NZDT,M9.5.0,M4.1.0/3'
    + +

    + This POSIX TZ string is hard to remember, and + mishandles some timestamps before 2008. + With this package you can use this instead: +

    + + 
    TZ='Pacific/Auckland'
    +
    • +
  • + POSIX does not define the DST transitions + for TZ values like + "EST5EDT". + Traditionally the current US DST rules + were used to interpret such values, but this meant that the + US DST rules were compiled into each + program that did time conversion. This meant that when + US time conversion rules changed (as in the United + States in 1987), all programs that did time conversion had to be + recompiled to ensure proper results. +
    • +
  • + The TZ environment variable is process-global, which + makes it hard to write efficient, thread-safe applications that + need access to multiple timezones. +
    • +
  • + In POSIX, there is no tamper-proof way for a process to learn the + system's best idea of local wall clock. + This is important for applications that an administrator wants + used only at certain times – without regard to whether the + user has fiddled the + TZ environment variable. + While an administrator can "do everything in UT" to + get around the problem, doing so is inconvenient and precludes + handling daylight saving time shifts – as might be required to + limit phone calls to off-peak hours. +
    • +
  • + POSIX provides no convenient and efficient way to determine + the UT offset and time zone abbreviation of arbitrary + timestamps, particularly for timezones + that do not fit into the POSIX model. +
    • +
  • + POSIX requires that systems ignore leap seconds. +
    • +
  • + The tz code attempts to support all the + time_t implementations allowed by POSIX. + The time_t type represents a nonnegative count of seconds + since 1970-01-01 00:00:00 UTC, ignoring leap seconds. + In practice, time_t is usually a signed 64- or 32-bit + integer; 32-bit signed time_t values stop working after + 2038-01-19 03:14:07 UTC, so new implementations these + days typically use a signed 64-bit integer. + Unsigned 32-bit integers are used on one or two platforms, and 36-bit + and 40-bit integers are also used occasionally. + Although earlier POSIX versions allowed time_t to be a + floating-point type, this was not supported by any practical system, + and POSIX.1-2013 and the tz code both + require time_t to be an integer type. +
    • +
+ +

Extensions to POSIX in the +tz code

+
    +
  • +

    + The TZ environment variable is used in generating + the name of a file from which time-related information is read + (or is interpreted à la POSIX); TZ is no longer + constrained to be a string containing abbreviations + and numeric data as described above. + The file's format is TZif, + a timezone information format that contains binary data. + The daylight saving time rules to be used for a + particular timezone are encoded in the + TZif file; the format of the file allows US, + Australian, and other rules to be encoded, and + allows for situations where more than two time zone + abbreviations are used. +

    +

    + It was recognized that allowing the TZ environment + variable to take on values such as 'America/New_York' + might cause "old" programs (that expect TZ to have a + certain form) to operate incorrectly; consideration was given to using + some other environment variable (for example, TIMEZONE) + to hold the string used to generate the TZif file's name. + In the end, however, it was decided to continue using + TZ: it is widely used for time zone purposes; + separately maintaining both TZ + and TIMEZONE seemed a nuisance; and systems where + "new" forms of TZ might cause problems can simply + use legacy TZ values such as "EST5EDT" which + can be used by "new" programs as well as by "old" programs that + assume pre-POSIX TZ values. +

    +
    • +
  • + The code supports platforms with a UT offset member + in struct tm, e.g., tm_gmtoff. +
    • +
  • + The code supports platforms with a time zone abbreviation member in + struct tm, e.g., tm_zone. +
    • +
  • + Functions tzalloc, tzfree, + localtime_rz, and mktime_z for + more-efficient thread-safe applications that need to use multiple + timezones. + The tzalloc and tzfree functions + allocate and free objects of type timezone_t, + and localtime_rz and mktime_z are + like localtime_r and mktime with an + extra timezone_t argument. + The functions were inspired by NetBSD. +
    • +
  • + A function tzsetwall has been added to arrange for the + system's best approximation to local wall clock time to be delivered + by subsequent calls to localtime. + Source code for portable applications that "must" run on local wall + clock time should call tzsetwall; + if such code is moved to "old" systems that do not + provide tzsetwall, you will not be able to generate an + executable program. + (These functions also arrange for local wall clock time to + be used if tzset is called – directly or + indirectly – and there is no TZ environment + variable; portable applications should not, however, rely on this + behavior since it is not the way SVR2 + systems behave.) +
    • +
  • + Negative time_t values are supported, on systems + where time_t is signed. +
    • +
  • + These functions can account for leap seconds, thanks to Bradley White. +
    • +
+ +

POSIX features no longer needed

+

+POSIX and ISO C +define some APIs that are vestigial: +they are not needed, and are relics of a too-simple model that does +not suffice to handle many real-world timestamps. +Although the tz code supports these +vestigial APIs for backwards compatibility, they should +be avoided in portable applications. +The vestigial APIs are: +

+
    +
  • + The POSIX tzname variable does not suffice and is no + longer needed. + To get a timestamp's time zone abbreviation, consult + the tm_zone member if available; otherwise, + use strftime's "%Z" conversion + specification. +
    • +
  • + The POSIX daylight and timezone + variables do not suffice and are no longer needed. + To get a timestamp's UT offset, consult + the tm_gmtoff member if available; otherwise, + subtract values returned by localtime + and gmtime using the rules of the Gregorian calendar, + or use strftime's "%z" conversion + specification if a string like "+0900" suffices. +
    • +
  • + The tm_isdst member is almost never needed and most of + its uses should be discouraged in favor of the abovementioned + APIs. + Although it can still be used in arguments to + mktime to disambiguate timestamps near + a DST transition when the clock jumps back, this + disambiguation does not work when standard time itself jumps back, + which can occur when a location changes to a time zone with a + lesser UT offset. +
    • +
+ +

Other portability notes

+
    +
  • + The 7th Edition + UNIX timezone function is not present in this + package; it is impossible to reliably map timezone's + arguments (a "minutes west of GMT" value and a + "daylight saving time in effect" flag) to a time zone + abbreviation, and we refuse to guess. + Programs that in the past used the timezone function + may now examine localtime(&clock)->tm_zone + (if TM_ZONE is defined) or + tzname[localtime(&clock)->tm_isdst] + (if HAVE_TZNAME is defined) to learn the correct time + zone abbreviation to use. +
    • +
  • + The 4.2BSD + gettimeofday function is not + used in this package. + This formerly let users obtain the current UTC offset + and DST flag, but this functionality was removed in + later versions of BSD. +
    • +
  • + In SVR2, time conversion fails for near-minimum or + near-maximum time_t values when doing conversions + for places that do not use UT. + This package takes care to do these conversions correctly. + A comment in the source code tells how to get compatibly wrong + results. +
    • +
  • + The functions that are conditionally compiled + if STD_INSPIRED is defined should, at this point, be + looked on primarily as food for thought. + They are not in any sense "standard compatible" – some are + not, in fact, specified in any standard. + They do, however, represent responses of various authors to + standardization proposals. +
    • +
  • + Other time conversion proposals, in particular those supported by the + Time Zone + Database Parser, offer a wider selection of functions + that provide capabilities beyond those provided here. + The absence of such functions from this package is not meant to + discourage the development, standardization, or use of such + functions. + Rather, their absence reflects the decision to make this package + contain valid extensions to POSIX, to ensure its broad + acceptability. + If more powerful time conversion functions can be standardized, so + much the better. +
    • +
+
+ +
+

Interface stability

+

+The tz code and data supply the following interfaces: +

+ +
    +
  • + A set of timezone names as per + "Names of timezones" above. +
    • +
  • + Library functions described in "Time and date + functions" above. +
    • +
  • + The programs tzselect, zdump, + and zic, documented in their man pages. +
    • +
  • + The format of zic input files, documented in + the zic man page. +
    • +
  • + The format of zic output files, documented in + the tzfile man page. +
    • +
  • + The format of zone table files, documented in zone1970.tab. +
    • +
  • + The format of the country code file, documented in iso3166.tab. +
    • +
  • + The version number of the code and data, as the first line of + the text file 'version' in each release. +
    • +
+ +

+Interface changes in a release attempt to preserve compatibility with +recent releases. +For example, tz data files typically do not +rely on recently-added zic features, so that users can +run older zic versions to process newer data files. +Downloading +the tz database describes how releases +are tagged and distributed. +

+ +

+Interfaces not listed above are less stable. +For example, users should not rely on particular UT +offsets or abbreviations for timestamps, as data entries are often +based on guesswork and these guesses may be corrected or improved. +

+
+ +
+

Calendrical issues

+

+Calendrical issues are a bit out of scope for a time zone database, +but they indicate the sort of problems that we would run into if we +extended the time zone database further into the past. +An excellent resource in this area is Edward M. Reingold +and Nachum Dershowitz, Calendrical +Calculations: The Ultimate Edition, Cambridge University Press (2018). +Other information and sources are given in the file 'calendars' +in the tz distribution. +They sometimes disagree. +

+
+ +
+

Time and time zones on other planets

+

+Some people's work schedules +use Mars time. +Jet Propulsion Laboratory (JPL) coordinators kept Mars time on +and off during the +Mars +Pathfinder mission. +Some of their family members also adapted to Mars time. +Dozens of special Mars watches were built for JPL workers who kept +Mars time during the Mars Exploration Rovers mission (2004). +These timepieces look like normal Seikos and Citizens but use Mars +seconds rather than terrestrial seconds. +

+ +

+A Mars solar day is called a "sol" and has a mean period equal to +about 24 hours 39 minutes 35.244 seconds in terrestrial time. +It is divided into a conventional 24-hour clock, so each Mars second +equals about 1.02749125 terrestrial seconds. +

+ +

+The prime +meridian of Mars goes through the center of the crater +Airy-0, named in +honor of the British astronomer who built the Greenwich telescope that +defines Earth's prime meridian. +Mean solar time on the Mars prime meridian is +called Mars +Coordinated Time (MTC). +

+ +

+Each landed mission on Mars has adopted a different reference for +solar timekeeping, so there is no real standard for Mars time zones. +For example, the +Mars +Exploration Rover project (2004) defined two time zones "Local +Solar Time A" and "Local Solar Time B" for its two missions, each zone +designed so that its time equals local true solar time at +approximately the middle of the nominal mission. +Such a "time zone" is not particularly suited for any application +other than the mission itself. +

+ +

+Many calendars have been proposed for Mars, but none have achieved +wide acceptance. +Astronomers often use Mars Sol Date (MSD) which is a +sequential count of Mars solar days elapsed since about 1873-12-29 +12:00 GMT. +

+ +

+In our solar system, Mars is the planet with time and calendar most +like Earth's. +On other planets, Sun-based time and calendars would work quite +differently. +For example, although Mercury's +sidereal +rotation period is 58.646 Earth days, Mercury revolves around the +Sun so rapidly that an observer on Mercury's equator would see a +sunrise only every 175.97 Earth days, i.e., a Mercury year is 0.5 of a +Mercury day. +Venus is more complicated, partly because its rotation is slightly +retrograde: +its year is 1.92 of its days. +Gas giants like Jupiter are trickier still, as their polar and +equatorial regions rotate at different rates, so that the length of a +day depends on latitude. +This effect is most pronounced on Neptune, where the day is about 12 +hours at the poles and 18 hours at the equator. +

+ +

+Although the tz database does not support +time on other planets, it is documented here in the hopes that support +will be added eventually. +

+ +

+Sources for time on other planets: +

+ + +
+ + + + diff --git a/contrib/tzdata/upstream-version b/contrib/tzdata/upstream-version index f6a71fe2f6..df68c8c7f9 100644 --- a/contrib/tzdata/upstream-version +++ b/contrib/tzdata/upstream-version @@ -1 +1 @@ -2018c +2018g diff --git a/contrib/tzdata/version b/contrib/tzdata/version index f6a71fe2f6..df68c8c7f9 100644 --- a/contrib/tzdata/version +++ b/contrib/tzdata/version @@ -1 +1 @@ -2018c +2018g diff --git a/contrib/tzdata/yearistype.sh b/contrib/tzdata/yearistype.sh index dfdcdf0e23..d6741759e8 100644 --- a/contrib/tzdata/yearistype.sh +++ b/contrib/tzdata/yearistype.sh @@ -1,4 +1,5 @@ #! /bin/sh +: 'Determine whether year is of appropriate type (this file is obsolete).' : 'This file is in the public domain, so clarified as of' : '2006-07-17 by Arthur David Olson.' diff --git a/contrib/tzdata/ziguard.awk b/contrib/tzdata/ziguard.awk new file mode 100644 index 0000000000..e3c729832d --- /dev/null +++ b/contrib/tzdata/ziguard.awk @@ -0,0 +1,107 @@ +# Convert tzdata source into vanguard or rearguard form. + +# Contributed by Paul Eggert. This file is in the public domain. + +# This is not a general-purpose converter; it is designed for current tzdata. +# +# When converting to vanguard form, the output can use negative SAVE +# values. +# +# When converting to rearguard form, the output uses only nonnegative +# SAVE values. The idea is for the output data to simulate the behavior +# of the input data as best it can within the constraints of the +# rearguard format. + +BEGIN { + dataform_type["vanguard"] = 1 + dataform_type["main"] = 1 + dataform_type["rearguard"] = 1 + + # The command line should set DATAFORM. + if (!dataform_type[DATAFORM]) exit 1 + vanguard = DATAFORM == "vanguard" +} + +/^Zone/ { zone = $2 } + +DATAFORM != "main" { + in_comment = /^#/ + uncomment = comment_out = 0 + + # If the line should differ due to Czechoslovakia using negative SAVE values, + # uncomment the desired version and comment out the undesired one. + if (zone == "Europe/Prague" && /1947 Feb 23/) { + if (($(in_comment + 2) != "-") == vanguard) { + uncomment = in_comment + } else { + comment_out = !in_comment + } + } + + # If this line should differ due to Ireland using negative SAVE values, + # uncomment the desired version and comment out the undesired one. + Rule_Eire = /^#?Rule[\t ]+Eire[\t ]/ + Zone_Dublin_post_1968 \ + = (zone == "Europe/Dublin" && /^#?[\t ]+[01]:00[\t ]/ \ + && (!$(in_comment + 4) || 1968 < $(in_comment + 4))) + if (Rule_Eire || Zone_Dublin_post_1968) { + if ((Rule_Eire \ + || (Zone_Dublin_post_1968 && $(in_comment + 3) == "IST/GMT")) \ + == vanguard) { + uncomment = in_comment + } else { + comment_out = !in_comment + } + } + + # If this line should differ due to Namibia using Rule SAVE suffixes, + # uncomment the desired version and comment out the undesired one. + Rule_Namibia = /^#?Rule[\t ]+Namibia[\t ]/ + Zone_using_Namibia_rule \ + = (zone == "Africa/Windhoek" \ + && ($(in_comment + 2) == "Namibia" \ + || (1994 <= $(in_comment + 4) && $(in_comment + 4) <= 2017) \ + || in_comment + 3 == NF)) + if (Rule_Namibia || Zone_using_Namibia_rule) { + if ((Rule_Namibia \ + ? ($(in_comment + 9) ~ /^-/ \ + || ($(in_comment + 9) == 0 && $(in_comment + 10) == "CAT")) \ + : $(in_comment + 1) == "2:00" && $(in_comment + 2) == "Namibia") \ + == vanguard) { + uncomment = in_comment + } else { + comment_out = !in_comment + } + } + + if (uncomment) { + sub(/^#/, "") + } + if (comment_out) { + sub(/^/, "#") + } + + # In rearguard format, change the Japan rule line with "Sat>=8 25:00" + # to "Sun>=9 1:00", to cater to zic before 2007 and to older Java. + if (!vanguard && $1 == "Rule" && $7 == "Sat>=8" && $8 == "25:00") { + sub(/Sat>=8/, "Sun>=9") + sub(/25:00/, " 1:00") + } +} + +# If a Link line is followed by a Zone line for the same data, comment +# out the Link line. This can happen if backzone overrides a Link +# with a Zone. +/^Link/ { + linkline[$3] = NR +} +/^Zone/ { + sub(/^Link/, "#Link", line[linkline[$2]]) +} + +{ line[NR] = $0 } + +END { + for (i = 1; i <= NR; i++) + print line[i] +} diff --git a/contrib/tzdata/zishrink.awk b/contrib/tzdata/zishrink.awk index 23d623e99d..8876b68a09 100644 --- a/contrib/tzdata/zishrink.awk +++ b/contrib/tzdata/zishrink.awk @@ -6,28 +6,146 @@ # 'zic' should treat this script's output as if it were identical to # this script's input. +# Record a hash N for the new name NAME, checking for collisions. -# Return a new rule name. -# N_RULE_NAMES keeps track of how many rule names have been generated. +function record_hash(n, name) +{ + if (used_hashes[n]) { + printf "# ! collision: %s %s\n", used_hashes[n], name + exit 1 + } + used_hashes[n] = name +} -function gen_rule_name(alphabet, base, rule_name, n, digit) +# Return a shortened rule name representing NAME, +# and record this relationship to the hash table. + +function gen_rule_name(name, n) { - alphabet = "" - alphabet = alphabet "ABCDEFGHIJKLMNOPQRSTUVWXYZ" - alphabet = alphabet "abcdefghijklmnopqrstuvwxyz" - alphabet = alphabet "!$%&'()*+,./:;<=>?@[\\]^_`{|}~" - base = length(alphabet) - rule_name = "" - n = n_rule_names++ - - do { - n -= rule_name && n <= base - digit = n % base - rule_name = substr(alphabet, digit + 1, 1) rule_name - n = (n - digit) / base - } while (n); - - return rule_name + # Use a simple memonic: the first two letters. + n = substr(name, 1, 2) + record_hash(n, name) + # printf "# %s = %s\n", n, name + return n +} + +function prehash_rule_names(name) +{ + # Rule names are not part of the tzdb API, so substitute shorter + # ones. Shortening them consistently from one release to the next + # simplifies comparison of the output. That being said, the + # 1-letter names below are not standardized in any way, and can + # change arbitrarily from one release to the next, as the main goal + # here is compression not comparison. + + # Abbreviating these rules names to one letter saved the most space + # circa 2018e. + rule["Arg"] = "A" + rule["Brazil"] = "B" + rule["Canada"] = "C" + rule["Denmark"] = "D" + rule["EU"] = "E" + rule["France"] = "F" + rule["GB-Eire"] = "G" + rule["Halifax"] = "H" + rule["Italy"] = "I" + rule["Jordan"] = "J" + rule["Egypt"] = "K" # "Kemet" in ancient Egyptian + rule["Libya"] = "L" + rule["Morocco"] = "M" + rule["Neth"] = "N" + rule["Poland"] = "O" # arbitrary + rule["Palestine"] = "P" + rule["Cuba"] = "Q" # Its start sounds like "Q". + rule["Russia"] = "R" + rule["Syria"] = "S" + rule["Turkey"] = "T" + rule["Uruguay"] = "U" + rule["Vincennes"] = "V" + rule["Winn"] = "W" + rule["Mongol"] = "X" # arbitrary + rule["NT_YK"] = "Y" + rule["Zion"] = "Z" + rule["Austria"] = "a" + rule["Belgium"] = "b" + rule["C-Eur"] = "c" + rule["Algeria"] = "d" # country code DZ + rule["E-Eur"] = "e" + rule["Taiwan"] = "f" # Formosa + rule["Greece"] = "g" + rule["Hungary"] = "h" + rule["Iran"] = "i" + rule["StJohns"] = "j" + rule["Chatham"] = "k" # arbitrary + rule["Lebanon"] = "l" + rule["Mexico"] = "m" + rule["Tunisia"] = "n" # country code TN + rule["Moncton"] = "o" # arbitrary + rule["Port"] = "p" + rule["Albania"] = "q" # arbitrary + rule["Regina"] = "r" + rule["Spain"] = "s" + rule["Toronto"] = "t" + rule["US"] = "u" + rule["Louisville"] = "v" # ville + rule["Iceland"] = "w" # arbitrary + rule["Chile"] = "x" # arbitrary + rule["Para"] = "y" # country code PY + rule["Romania"] = "z" # arbitrary + rule["Macau"] = "_" # arbitrary + + # Use ISO 3166 alpha-2 country codes for remaining names that are countries. + # This is more systematic, and avoids collisions (e.g., Malta and Moldova). + rule["Armenia"] = "AM" + rule["Aus"] = "AU" + rule["Azer"] = "AZ" + rule["Barb"] = "BB" + rule["Dhaka"] = "BD" + rule["Bulg"] = "BG" + rule["Bahamas"] = "BS" + rule["Belize"] = "BZ" + rule["Swiss"] = "CH" + rule["Cook"] = "CK" + rule["PRC"] = "CN" + rule["Cyprus"] = "CY" + rule["Czech"] = "CZ" + rule["Germany"] = "DE" + rule["DR"] = "DO" + rule["Ecuador"] = "EC" + rule["Finland"] = "FI" + rule["Fiji"] = "FJ" + rule["Falk"] = "FK" + rule["Ghana"] = "GH" + rule["Guat"] = "GT" + rule["Hond"] = "HN" + rule["Haiti"] = "HT" + rule["Eire"] = "IE" + rule["Iraq"] = "IQ" + rule["Japan"] = "JP" + rule["Kyrgyz"] = "KG" + rule["ROK"] = "KR" + rule["Latvia"] = "LV" + rule["Lux"] = "LX" + rule["Moldova"] = "MD" + rule["Malta"] = "MT" + rule["Mauritius"] = "MU" + rule["Namibia"] = "NA" + rule["Nic"] = "NI" + rule["Norway"] = "NO" + rule["Peru"] = "PE" + rule["Phil"] = "PH" + rule["Pakistan"] = "PK" + rule["Sudan"] = "SD" + rule["Salv"] = "SV" + rule["Tonga"] = "TO" + rule["Vanuatu"] = "VU" + + # Avoid collisions. + rule["Detroit"] = "Dt" # De = Denver + + for (name in rule) { + record_hash(rule[name], name) + } } # Process an input line and save it for later output. @@ -37,7 +155,7 @@ function process_input_line(line, field, end, i, n, startdef) # Remove comments, normalize spaces, and append a space to each line. sub(/#.*/, "", line) line = line " " - gsub(/[\f\r\t\v ]+/, " ", line) + gsub(/[\t ]+/, " ", line) # Abbreviate keywords. Do not abbreviate "Link" to just "L", # as pre-2017c zic erroneously diagnoses "Li" as ambiguous. @@ -106,7 +224,7 @@ function process_input_line(line, field, end, i, n, startdef) i = field[1] == "Z" ? 4 : field[1] == "Li" ? 0 : 2 if (i && field[i] ~ /^[^-+0-9]/) { if (!rule[field[i]]) - rule[field[i]] = gen_rule_name() + rule[field[i]] = gen_rule_name(field[i]) field[i] = rule[field[i]] } @@ -144,11 +262,56 @@ function output_saved_lines(i) } BEGIN { + # Files that the output normally depends on. + default_dep["africa"] = 1 + default_dep["antarctica"] = 1 + default_dep["asia"] = 1 + default_dep["australasia"] = 1 + default_dep["backward"] = 1 + default_dep["etcetera"] = 1 + default_dep["europe"] = 1 + default_dep["factory"] = 1 + default_dep["northamerica"] = 1 + default_dep["southamerica"] = 1 + default_dep["systemv"] = 1 + default_dep["ziguard.awk"] = 1 + default_dep["zishrink.awk"] = 1 + + # Output a version string from 'version' and related configuration variables + # supported by tzdb's Makefile. If you change the makefile or any other files + # that affect the output of this script, you should append '-SOMETHING' + # to the contents of 'version', where SOMETHING identifies what was changed. + + ndeps = split(deps, dep) + ddeps = "" + for (i = 1; i <= ndeps; i++) { + if (default_dep[dep[i]]) { + default_dep[dep[i]]++ + } else { + ddeps = ddeps " " dep[i] + } + } + for (d in default_dep) { + if (default_dep[d] == 1) { + ddeps = ddeps " !" d + } + } print "# version", version + if (dataform != "main") { + print "# dataform", dataform + } + if (redo != "posix_right") { + print "# redo " redo + } + if (ddeps) { + print "# ddeps" ddeps + } print "# This zic input file is in the public domain." + + prehash_rule_names() } -/^[\f\r\t\v ]*[^#\f\r\t\v ]/ { +/^[\t ]*[^#\t ]/ { process_input_line($0) } diff --git a/contrib/tzdata/zone.tab b/contrib/tzdata/zone.tab index e1bfdee2ec..dcb6e1da60 100644 --- a/contrib/tzdata/zone.tab +++ b/contrib/tzdata/zone.tab @@ -1,9 +1,9 @@ -# tz zone descriptions (deprecated version) +# tzdb timezone descriptions (deprecated version) # # This file is in the public domain, so clarified as of # 2009-05-17 by Arthur David Olson. # -# From Paul Eggert (2014-07-31): +# From Paul Eggert (2018-06-27): # This file is intended as a backward-compatibility aid for older programs. # New programs should use zone1970.tab. This file is like zone1970.tab (see # zone1970.tab's comments), but with the following additional restrictions: @@ -12,13 +12,13 @@ # 2. The first data column contains exactly one country code. # # Because of (2), each row stands for an area that is the intersection -# of a region identified by a country code and of a zone where civil +# of a region identified by a country code and of a timezone where civil # clocks have agreed since 1970; this is a narrower definition than # that of zone1970.tab. # -# This table is intended as an aid for users, to help them select time -# zone data entries appropriate for their practical needs. It is not -# intended to take or endorse any position on legal or territorial claims. +# This table is intended as an aid for users, to help them select timezones +# appropriate for their practical needs. It is not intended to take or +# endorse any position on legal or territorial claims. # #country- #code coordinates TZ comments @@ -268,7 +268,7 @@ MM +1647+09610 Asia/Yangon MN +4755+10653 Asia/Ulaanbaatar Mongolia (most areas) MN +4801+09139 Asia/Hovd Bayan-Olgiy, Govi-Altai, Hovd, Uvs, Zavkhan MN +4804+11430 Asia/Choibalsan Dornod, Sukhbaatar -MO +2214+11335 Asia/Macau +MO +221150+1133230 Asia/Macau MP +1512+14545 Pacific/Saipan MQ +1436-06105 America/Martinique MR +1806-01557 Africa/Nouakchott @@ -429,7 +429,7 @@ US +593249-1394338 America/Yakutat Alaska - Yakutat US +643004-1652423 America/Nome Alaska (west) US +515248-1763929 America/Adak Aleutian Islands US +211825-1575130 Pacific/Honolulu Hawaii -UY -3453-05611 America/Montevideo +UY -345433-0561245 America/Montevideo UZ +3940+06648 Asia/Samarkand Uzbekistan (west) UZ +4120+06918 Asia/Tashkent Uzbekistan (east) VA +415408+0122711 Europe/Vatican diff --git a/contrib/tzdata/zone1970.tab b/contrib/tzdata/zone1970.tab index 4ee8ce519d..7c86fb6911 100644 --- a/contrib/tzdata/zone1970.tab +++ b/contrib/tzdata/zone1970.tab @@ -1,35 +1,35 @@ -# tz zone descriptions +# tzdb timezone descriptions # # This file is in the public domain. # -# From Paul Eggert (2017-10-01): -# This file contains a table where each row stands for a zone where -# civil time stamps have agreed since 1970. Columns are separated by +# From Paul Eggert (2018-06-27): +# This file contains a table where each row stands for a timezone where +# civil timestamps have agreed since 1970. Columns are separated by # a single tab. Lines beginning with '#' are comments. All text uses # UTF-8 encoding. The columns of the table are as follows: # -# 1. The countries that overlap the zone, as a comma-separated list +# 1. The countries that overlap the timezone, as a comma-separated list # of ISO 3166 2-character country codes. See the file 'iso3166.tab'. -# 2. Latitude and longitude of the zone's principal location +# 2. Latitude and longitude of the timezone's principal location # in ISO 6709 sign-degrees-minutes-seconds format, -# either +-DDMM+-DDDMM or +-DDMMSS+-DDDMMSS, +# either ±DDMM±DDDMM or ±DDMMSS±DDDMMSS, # first latitude (+ is north), then longitude (+ is east). -# 3. Zone name used in value of TZ environment variable. -# Please see the theory.html file for how zone names are chosen. -# If multiple zones overlap a country, each has a row in the +# 3. Timezone name used in value of TZ environment variable. +# Please see the theory.html file for how these names are chosen. +# If multiple timezones overlap a country, each has a row in the # table, with each column 1 containing the country code. -# 4. Comments; present if and only if a country has multiple zones. +# 4. Comments; present if and only if a country has multiple timezones. # -# If a zone covers multiple countries, the most-populous city is used, +# If a timezone covers multiple countries, the most-populous city is used, # and that country is listed first in column 1; any other countries # are listed alphabetically by country code. The table is sorted # first by country code, then (if possible) by an order within the # country that (1) makes some geographical sense, and (2) puts the -# most populous zones first, where that does not contradict (1). +# most populous timezones first, where that does not contradict (1). # -# This table is intended as an aid for users, to help them select time -# zone data entries appropriate for their practical needs. It is not -# intended to take or endorse any position on legal or territorial claims. +# This table is intended as an aid for users, to help them select timezones +# appropriate for their practical needs. It is not intended to take or +# endorse any position on legal or territorial claims. # #country- #codes coordinates TZ comments @@ -231,7 +231,7 @@ MM +1647+09610 Asia/Yangon MN +4755+10653 Asia/Ulaanbaatar Mongolia (most areas) MN +4801+09139 Asia/Hovd Bayan-Ölgii, Govi-Altai, Hovd, Uvs, Zavkhan MN +4804+11430 Asia/Choibalsan Dornod, Sükhbaatar -MO +2214+11335 Asia/Macau +MO +221150+1133230 Asia/Macau MQ +1436-06105 America/Martinique MT +3554+01431 Europe/Malta MU -2010+05730 Indian/Mauritius @@ -371,7 +371,7 @@ US +593249-1394338 America/Yakutat Alaska - Yakutat US +643004-1652423 America/Nome Alaska (west) US +515248-1763929 America/Adak Aleutian Islands US,UM +211825-1575130 Pacific/Honolulu Hawaii -UY -3453-05611 America/Montevideo +UY -345433-0561245 America/Montevideo UZ +3940+06648 Asia/Samarkand Uzbekistan (west) UZ +4120+06918 Asia/Tashkent Uzbekistan (east) VE +1030-06656 America/Caracas diff --git a/contrib/tzdata/zoneinfo2tdf.pl b/contrib/tzdata/zoneinfo2tdf.pl index e05ec01008..c8c5591afe 100755 --- a/contrib/tzdata/zoneinfo2tdf.pl +++ b/contrib/tzdata/zoneinfo2tdf.pl @@ -1,4 +1,5 @@ #! /usr/bin/perl -w +# Summarize .zi input in a .zi-like format. # Courtesy Ken Pizzini. -- 2.11.4.GIT