1 ;;; timezone.el --- time zone package for GNU Emacs
3 ;; Copyright (C) 1990, 1991, 1992, 1993, 1996, 1999 Free Software Foundation, Inc.
5 ;; Author: Masanobu Umeda
6 ;; Maintainer: umerin@mse.kyutech.ac.jp
9 ;; This file is part of GNU Emacs.
11 ;; GNU Emacs is free software; you can redistribute it and/or modify
12 ;; it under the terms of the GNU General Public License as published by
13 ;; the Free Software Foundation; either version 2, or (at your option)
16 ;; GNU Emacs is distributed in the hope that it will be useful,
17 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
18 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 ;; GNU General Public License for more details.
21 ;; You should have received a copy of the GNU General Public License
22 ;; along with GNU Emacs; see the file COPYING. If not, write to the
23 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
24 ;; Boston, MA 02111-1307, USA.
28 (defvar timezone-world-timezones
37 ("AST" . -
400) ;by <clamen@CS.CMU.EDU>
38 ("NST" . -
330) ;by <clamen@CS.CMU.EDU>
45 ("GMT+1" .
+100) ("GMT+2" .
+200) ("GMT+3" .
+300)
46 ("GMT+4" .
+400) ("GMT+5" .
+500) ("GMT+6" .
+600)
47 ("GMT+7" .
+700) ("GMT+8" .
+800) ("GMT+9" .
+900)
48 ("GMT+10" .
+1000) ("GMT+11" .
+1100) ("GMT+12" .
+1200) ("GMT+13" .
+1300)
49 ("GMT-1" . -
100) ("GMT-2" . -
200) ("GMT-3" . -
300)
50 ("GMT-4" . -
400) ("GMT-5" . -
500) ("GMT-6" . -
600)
51 ("GMT-7" . -
700) ("GMT-8" . -
800) ("GMT-9" . -
900)
52 ("GMT-10" . -
1000) ("GMT-11" . -
1100) ("GMT-12" . -
1200))
53 "*Time differentials of timezone from GMT in +-HHMM form.
54 This list is obsolescent, and is present only for backwards compatibility,
55 because time zone names are ambiguous in practice.
56 Use `current-time-zone' instead.")
58 (defvar timezone-months-assoc
59 '(("JAN" .
1)("FEB" .
2)("MAR" .
3)
60 ("APR" .
4)("MAY" .
5)("JUN" .
6)
61 ("JUL" .
7)("AUG" .
8)("SEP" .
9)
62 ("OCT" .
10)("NOV" .
11)("DEC" .
12))
63 "Alist of first three letters of a month and its numerical representation.")
65 (defun timezone-make-date-arpa-standard (date &optional local timezone
)
66 "Convert DATE to an arpanet standard date.
67 Optional 2nd argument LOCAL specifies the default local timezone of the DATE;
68 if nil, GMT is assumed.
69 Optional 3rd argument TIMEZONE specifies a time zone to be represented in;
70 if nil, the local time zone is assumed."
71 (let ((new (timezone-fix-time date local timezone
)))
72 (timezone-make-arpa-date (aref new
0) (aref new
1) (aref new
2)
73 (timezone-make-time-string
74 (aref new
3) (aref new
4) (aref new
5))
78 (defun timezone-make-date-sortable (date &optional local timezone
)
79 "Convert DATE to a sortable date string.
80 Optional 2nd argument LOCAL specifies the default local timezone of the DATE;
81 if nil, GMT is assumed.
82 Optional 3rd argument TIMEZONE specifies a timezone to be represented in;
83 if nil, the local time zone is assumed."
84 (let ((new (timezone-fix-time date local timezone
)))
85 (timezone-make-sortable-date (aref new
0) (aref new
1) (aref new
2)
86 (timezone-make-time-string
87 (aref new
3) (aref new
4) (aref new
5)))
92 ;; Parsers and Constructors of Date and Time
95 (defun timezone-make-arpa-date (year month day time
&optional timezone
)
96 "Make arpanet standard date string from YEAR, MONTH, DAY, and TIME.
97 Optional argument TIMEZONE specifies a time zone."
100 (let* ((m (timezone-zone-to-minute timezone
))
101 (absm (if (< m
0) (- m
) m
)))
103 (if (< m
0) ?- ?
+) (/ absm
60) (% absm
60)))
105 (format "%02d %s %04d %s %s"
107 (capitalize (car (rassq month timezone-months-assoc
)))
112 (defun timezone-make-sortable-date (year month day time
)
113 "Make sortable date string from YEAR, MONTH, DAY, and TIME."
114 (format "%4d%02d%02d%s"
115 year month day time
))
117 (defun timezone-make-time-string (hour minute second
)
118 "Make time string from HOUR, MINUTE, and SECOND."
119 (format "%02d:%02d:%02d" hour minute second
))
121 (defun timezone-parse-date (date)
122 "Parse DATE and return a vector [YEAR MONTH DAY TIME TIMEZONE].
123 19 is prepended to year if necessary. Timezone may be nil if nothing.
124 Understands the following styles:
125 (1) 14 Apr 89 03:20[:12] [GMT]
126 (2) Fri, 17 Mar 89 4:01[:33] [GMT]
127 (3) Mon Jan 16 16:12[:37] [GMT] 1989
128 (4) 6 May 1992 1641-JST (Wednesday)
129 (5) 22-AUG-1993 10:59:12.82
130 (6) Thu, 11 Apr 16:17:12 91 [MET]
131 (7) Mon, 6 Jul 16:47:20 T 1992 [MET]
132 (8) 1996-06-24 21:13:12 [GMT]
133 (9) 1996-06-24 21:13-ZONE"
134 ;; Get rid of any text properties.
136 (or (text-properties-at 0 date
)
137 (next-property-change 0 date
))
138 (setq date
(copy-sequence date
))
139 (set-text-properties 0 (length date
) nil date
))
140 (let ((date (or date
""))
145 (zone nil
)) ;This may be nil.
147 "\\([0-9]+\\)[ \t]+\\([^ \t,]+\\)[ \t]+\\([0-9]+\\)[ \t]+\\([0-9]+:[0-9:]+\\)[ \t]*\\([-+a-zA-Z0-9]+\\)" date
)
148 ;; Styles: (1) and (2) with timezone and buggy timezone
149 ;; This is most common in mail and news,
150 ;; so it is worth trying first.
151 (setq year
3 month
2 day
1 time
4 zone
5))
153 "\\([0-9]+\\)[ \t]+\\([^ \t,]+\\)[ \t]+\\([0-9]+\\)[ \t]+\\([0-9]+:[0-9:]+\\)[ \t]*\\'" date
)
154 ;; Styles: (1) and (2) without timezone
155 (setq year
3 month
2 day
1 time
4 zone nil
))
157 "\\([^ \t,]+\\),[ \t]+\\([0-9]+\\)[ \t]+\\([^ \t,]+\\)[ \t]+\\([0-9]+:[0-9:]+\\)[ \t]+\\(T[ \t]+\\|\\)\\([0-9]+\\)[ \t]*\\'" date
)
158 ;; Styles: (6) and (7) without timezone
159 (setq year
6 month
3 day
2 time
4 zone nil
))
161 "\\([^ \t,]+\\),[ \t]+\\([0-9]+\\)[ \t]+\\([^ \t,]+\\)[ \t]+\\([0-9]+:[0-9:]+\\)[ \t]+\\(T[ \t]+\\|\\)\\([0-9]+\\)[ \t]*\\([-+a-zA-Z0-9]+\\)" date
)
162 ;; Styles: (6) and (7) with timezone and buggy timezone
163 (setq year
6 month
3 day
2 time
4 zone
7))
165 "\\([^ \t,]+\\)[ \t]+\\([0-9]+\\)[ \t]+\\([0-9]+:[0-9:]+\\)[ \t]+\\([0-9]+\\)" date
)
166 ;; Styles: (3) without timezone
167 (setq year
4 month
1 day
2 time
3 zone nil
))
169 "\\([^ \t,]+\\)[ \t]+\\([0-9]+\\)[ \t]+\\([0-9]+:[0-9:]+\\)[ \t]+\\([-+a-zA-Z0-9]+\\)[ \t]+\\([0-9]+\\)" date
)
170 ;; Styles: (3) with timezone
171 (setq year
5 month
1 day
2 time
3 zone
4))
173 "\\([0-9]+\\)[ \t]+\\([^ \t,]+\\)[ \t]+\\([0-9]+\\)[ \t]+\\([0-9]+\\)[ \t]*\\([-+a-zA-Z0-9]+\\)" date
)
174 ;; Styles: (4) with timezone
175 (setq year
3 month
2 day
1 time
4 zone
5))
177 "\\([0-9]+\\)-\\([A-Za-z]+\\)-\\([0-9]+\\)[ \t]+\\([0-9]+:[0-9]+:[0-9]+\\)\\(\\.[0-9]+\\)?[ \t]+\\([-+a-zA-Z0-9]+\\)" date
)
178 ;; Styles: (5) with timezone.
179 (setq year
3 month
2 day
1 time
4 zone
6))
181 "\\([0-9]+\\)-\\([A-Za-z]+\\)-\\([0-9]+\\)[ \t]+\\([0-9]+:[0-9]+:[0-9]+\\)\\(\\.[0-9]+\\)?" date
)
182 ;; Styles: (5) without timezone.
183 (setq year
3 month
2 day
1 time
4 zone nil
))
185 "\\([0-9]+\\)-\\([0-9]+\\)-\\([0-9]+\\)[ \t]+\\([0-9]+:[0-9]+:[0-9]+\\)[ \t]*\\([-+a-zA-Z0-9]+\\)" date
)
186 ;; Styles: (8) with timezone.
187 (setq year
1 month
2 day
3 time
4 zone
5))
189 "\\([0-9]+\\)-\\([0-9]+\\)-\\([0-9]+\\)[ \t]+\\([0-9]+:[0-9]+\\)[ \t]*\\([-+a-zA-Z0-9:]+\\)" date
)
190 ;; Styles: (8) with timezone with a colon in it.
191 (setq year
1 month
2 day
3 time
4 zone
5))
193 "\\([0-9]+\\)-\\([0-9]+\\)-\\([0-9]+\\)[ \t]+\\([0-9]+:[0-9]+:[0-9]+\\)" date
)
194 ;; Styles: (8) without timezone.
195 (setq year
1 month
2 day
3 time
4 zone nil
))
198 (setq year
(match-string year date
))
199 ;; Guess ambiguous years. Assume years < 69 don't predate the
200 ;; Unix Epoch, so are 2000+. Three-digit years are assumed to
201 ;; be relative to 1900.
202 (if (< (length year
) 4)
203 (let ((y (string-to-int year
)))
206 (setq year
(int-to-string (+ 1900 y
)))))
208 (if (= (aref date
(+ (match-beginning month
) 2)) ?-
)
209 ;; Handle numeric months, spanning exactly two digits.
211 (match-beginning month
)
212 (+ (match-beginning month
) 2))
213 (let* ((string (substring date
214 (match-beginning month
)
215 (+ (match-beginning month
) 3)))
217 (cdr (assoc (upcase string
) timezone-months-assoc
))))
219 (int-to-string monthnum
)))))
220 (setq day
(match-string day date
))
221 (setq time
(match-string time date
)))
222 (if zone
(setq zone
(match-string zone date
)))
225 (vector year month day time zone
)
226 (vector "0" "0" "0" "0" nil
))))
228 (defun timezone-parse-time (time)
229 "Parse TIME (HH:MM:SS) and return a vector [hour minute second].
230 Recognize HH:MM:SS, HH:MM, HHMMSS, HHMM."
231 (let ((time (or time
""))
233 (cond ((string-match "\\`\\([0-9]+\\):\\([0-9]+\\):\\([0-9]+\\)\\'" time
)
235 (setq hour
1 minute
2 second
3))
236 ((string-match "\\`\\([0-9]+\\):\\([0-9]+\\)\\'" time
)
238 (setq hour
1 minute
2 second nil
))
239 ((string-match "\\`\\([0-9][0-9]\\)\\([0-9][0-9]\\)\\([0-9][0-9]\\)\\'" time
)
241 (setq hour
1 minute
2 second
3))
242 ((string-match "\\`\\([0-9][0-9]\\)\\([0-9][0-9]\\)\\'" time
)
244 (setq hour
1 minute
2 second nil
))
246 ;; Return [hour minute second]
248 (if hour
(match-string hour time
) "0")
249 (if minute
(match-string minute time
) "0")
250 (if second
(match-string second time
) "0"))))
255 (defun timezone-zone-to-minute (timezone)
256 "Translate TIMEZONE to an integer minute offset from GMT.
257 TIMEZONE can be a cons cell containing the output of current-time-zone,
258 or an integer of the form +-HHMM, or a time zone name."
261 (/ (car timezone
) 60))
265 (or (cdr (assoc (upcase timezone
) timezone-world-timezones
))
268 (if (stringp timezone
)
269 (setq timezone
(string-to-int timezone
)))
270 ;; Taking account of minute in timezone.
272 (let* ((abszone (abs timezone
))
273 (minutes (+ (* 60 (/ abszone
100)) (% abszone
100))))
274 (if (< timezone
0) (- minutes
) minutes
))))
277 (defun timezone-time-from-absolute (date seconds
)
278 "Compute the UTC time equivalent to DATE at time SECONDS after midnight.
279 Return a list suitable as an argument to current-time-zone,
280 or nil if the date cannot be thus represented.
281 DATE is the number of days elapsed since the (imaginary)
282 Gregorian date Sunday, December 31, 1 BC."
283 (let* ((current-time-origin 719163)
284 ;; (timezone-absolute-from-gregorian 1 1 1970)
285 (days (- date current-time-origin
))
286 (seconds-per-day (float 86400))
287 (seconds (+ seconds
(* days seconds-per-day
)))
288 (current-time-arithmetic-base (float 65536))
289 (hi (floor (/ seconds current-time-arithmetic-base
)))
290 (hibase (* hi current-time-arithmetic-base
))
291 (lo (floor (- seconds hibase
))))
292 (and (< (abs (- seconds
(+ hibase lo
))) 2) ;; Check for integer overflow.
295 (defun timezone-time-zone-from-absolute (date seconds
)
296 "Compute the local time zone for DATE at time SECONDS after midnight.
297 Return a list in the same format as current-time-zone's result,
298 or nil if the local time zone could not be computed.
299 DATE is the number of days elapsed since the (imaginary)
300 Gregorian date Sunday, December 31, 1 BC."
301 (and (fboundp 'current-time-zone
)
302 (let ((utc-time (timezone-time-from-absolute date seconds
)))
304 (let ((zone (current-time-zone utc-time
)))
305 (and (car zone
) zone
))))))
307 (defun timezone-fix-time (date local timezone
)
308 "Convert DATE (default timezone LOCAL) to YYYY-MM-DD-HH-MM-SS-ZONE vector.
309 If LOCAL is nil, it is assumed to be GMT.
310 If TIMEZONE is nil, use the local time zone."
311 (let* ((date (timezone-parse-date date
))
312 (year (string-to-int (aref date
0)))
313 (year (cond ((< year
69)
317 ((< year
1000) ; possible 3-digit years.
320 (month (string-to-int (aref date
1)))
321 (day (string-to-int (aref date
2)))
322 (time (timezone-parse-time (aref date
3)))
323 (hour (string-to-int (aref time
0)))
324 (minute (string-to-int (aref time
1)))
325 (second (string-to-int (aref time
2)))
326 (local (or (aref date
4) local
)) ;Use original if defined
329 (timezone-time-zone-from-absolute
330 (timezone-absolute-from-gregorian month day year
)
331 (+ second
(* 60 (+ minute
(* 60 hour
)))))))
332 (diff (- (timezone-zone-to-minute timezone
)
333 (timezone-zone-to-minute local
)))
334 (minute (+ minute diff
))
335 (hour-fix (floor minute
60)))
336 (setq hour
(+ hour hour-fix
))
337 (setq minute
(- minute
(* 60 hour-fix
)))
338 ;; HOUR may be larger than 24 or smaller than 0.
339 (cond ((<= 24 hour
) ;24 -> 00
340 (setq hour
(- hour
24))
342 (if (< (timezone-last-day-of-month month year
) day
)
344 (setq month
(1+ month
))
349 (setq year
(1+ year
))
353 (setq hour
(+ hour
24))
357 (setq month
(1- month
))
361 (setq year
(1- year
))
363 (setq day
(timezone-last-day-of-month month year
))
366 (vector year month day hour minute second timezone
)))
368 ;; Partly copied from Calendar program by Edward M. Reingold.
371 (defun timezone-last-day-of-month (month year
)
372 "The last day in MONTH during YEAR."
373 (if (and (= month
2) (timezone-leap-year-p year
))
375 (aref [31 28 31 30 31 30 31 31 30 31 30 31] (1- month
))))
377 (defun timezone-leap-year-p (year)
378 "Returns t if YEAR is a Gregorian leap year."
379 (or (and (zerop (% year
4))
380 (not (zerop (% year
100))))
381 (zerop (% year
400))))
383 (defun timezone-day-number (month day year
)
384 "Return the day number within the year of the date month/day/year."
385 (let ((day-of-year (+ day
(* 31 (1- month
)))))
388 (setq day-of-year
(- day-of-year
(/ (+ 23 (* 4 month
)) 10)))
389 (if (timezone-leap-year-p year
)
390 (setq day-of-year
(1+ day-of-year
)))))
393 (defun timezone-absolute-from-gregorian (month day year
)
394 "The number of days between the Gregorian date 12/31/1 BC and month/day/year.
395 The Gregorian date Sunday, December 31, 1 BC is imaginary."
396 (+ (timezone-day-number month day year
);; Days this year
397 (* 365 (1- year
));; + Days in prior years
398 (/ (1- year
) 4);; + Julian leap years
399 (- (/ (1- year
) 100));; - century years
400 (/ (1- year
) 400)));; + Gregorian leap years
404 ;;; timezone.el ends here