1 # @(#)northamerica 7.71
2 # also includes Central America and the Caribbean
4 # This data is by no means authoritative; if you think you know better,
5 # go ahead and edit the file (and please send any changes to
6 # tz@elsie.nci.nih.gov for general use in the future).
8 # From Paul Eggert <eggert@twinsun.com> (1999-03-22):
9 # A reliable and entertaining source about time zones is
10 # Derek Howse, Greenwich time and longitude, Philip Wilson Publishers (1997).
12 ###############################################################################
16 # From Paul Eggert (1999-03-31):
17 # Howse writes (pp 121-125) that time zones were invented by
18 # Professor Charles Ferdinand Dowd (1825-1904),
19 # Principal of Temple Grove Ladies' Seminary (Saratoga Springs, NY).
20 # His pamphlet ``A System of National Time for Railroads'' (1870)
21 # was the result of his proposals at the Convention of Railroad Trunk Lines
22 # in New York City (1869-10). His 1870 proposal was based on Washington, DC,
23 # but in 1872-05 he moved the proposed origin to Greenwich.
24 # His proposal was adopted by the railroads on 1883-11-18 at 12:00,
25 # and the most of the country soon followed suit.
27 # From Paul Eggert <eggert@twinsun.com> (1995-12-19):
28 # A good source for time zone historical data in the US is
29 # Thomas G. Shanks, The American Atlas (5th edition),
30 # San Diego: ACS Publications, Inc. (1991).
31 # Make sure you have the errata sheet; the book is somewhat useless without it.
32 # It is the source for the US and Puerto Rico entries below.
34 # From Paul Eggert (2001-03-06):
35 # Daylight Saving Time was first suggested as a joke by Benjamin Franklin
36 # in his whimsical essay ``An Economical Project for Diminishing the Cost
37 # of Light'' published in the Journal de Paris (1784-04-26).
38 # Not everyone is happy with the results:
40 # I don't really care how time is reckoned so long as there is some
41 # agreement about it, but I object to being told that I am saving
42 # daylight when my reason tells me that I am doing nothing of the kind.
43 # I even object to the implication that I am wasting something
44 # valuable if I stay in bed after the sun has risen. As an admirer
45 # of moonlight I resent the bossy insistence of those who want to
46 # reduce my time for enjoying it. At the back of the Daylight Saving
47 # scheme I detect the bony, blue-fingered hand of Puritanism, eager
48 # to push people into bed earlier, and get them up earlier, to make
49 # them healthy, wealthy and wise in spite of themselves.
51 # -- Robertson Davies, The Diary of Samuel Marchbanks (1947), XIX, Sunday
53 # For more about the first ten years of DST in the United States, see
54 # Robert Garland's <a href="http://www.clpgh.org/exhibit/dst.html">
55 # Ten years of daylight saving from the Pittsburgh standpoint
56 # (Carnegie Library of Pittsburgh, 1927)</a>.
58 # Shanks says that DST was called "War Time" in the US in 1918 and 1919.
59 # However, DST was imposed by the Standard Time Act of 1918, which
60 # was the first nationwide legal time standard, and apparently
61 # time was just called "Standard Time" or "Daylight Saving Time".
63 # From Arthur David Olson:
64 # US Daylight Saving Time ended on the last Sunday of *October* in 1974.
65 # See, for example, the front page of the Saturday, 1974-10-26
66 # and Sunday, 1974-10-27 editions of the Washington Post.
68 # From Arthur David Olson:
69 # Before the Uniform Time Act of 1966 took effect in 1967, observance of
70 # Daylight Saving Time in the US was by local option, except during wartime.
72 # From Arthur David Olson (2000-09-25):
73 # Last night I heard part of a rebroadcast of a 1945 Arch Oboler radio drama.
74 # In the introduction, Oboler spoke of "Eastern Peace Time."
75 # An AltaVista search turned up
76 # <a href="http://rowayton.org/rhs/hstaug45.html">:
77 # "When the time is announced over the radio now, it is 'Eastern Peace
78 # Time' instead of the old familiar 'Eastern War Time.' Peace is wonderful."
79 # </a> (August 1945) by way of confirmation.
81 # From Joseph Gallant <notquite@hotmail.com>, citing
82 # George H. Douglas, _The Early Days of Radio Broadcasting_ (1987):
83 # At 7 P.M. (Eastern War Time) [on 1945-08-14], the networks were set
84 # to switch to London for Attlee's address, but the American people
85 # never got to hear his speech live. According to one press account,
86 # CBS' Bob Trout was first to announce the word of Japan's surrender,
87 # but a few seconds later, NBC, ABC and Mutual also flashed the word
88 # of surrender, all of whom interrupting the bells of Big Ben in
89 # London which were to precede Mr. Attlee's speech.
91 # From Paul Eggert (2003-02-09): It was Robert St John, not Bob Trout. From
92 # Myrna Oliver's obituary of St John on page B16 of today's Los Angeles Times:
94 # ... a war-weary U.S. clung to radios, awaiting word of Japan's surrender.
95 # Any announcement from Asia would reach St. John's New York newsroom on a
96 # wire service teletype machine, which had prescribed signals for major news.
97 # Associated Press, for example, would ring five bells before spewing out
98 # typed copy of an important story, and 10 bells for news "of transcendental
101 # On Aug. 14, stalling while talking steadily into the NBC networks' open
102 # microphone, St. John heard five bells and waited only to hear a sixth bell,
103 # before announcing confidently: "Ladies and gentlemen, World War II is over.
104 # The Japanese have agreed to our surrender terms."
106 # He had scored a 20-second scoop on other broadcasters.
108 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
109 Rule US 1918 1919 - Mar lastSun 2:00 1:00 D
110 Rule US 1918 1919 - Oct lastSun 2:00 0 S
111 Rule US 1942 only - Feb 9 2:00 1:00 W # War
112 Rule US 1945 only - Aug 14 23:00u 1:00 P # Peace
113 Rule US 1945 only - Sep 30 2:00 0 S
114 Rule US 1967 max - Oct lastSun 2:00 0 S
115 Rule US 1967 1973 - Apr lastSun 2:00 1:00 D
116 Rule US 1974 only - Jan 6 2:00 1:00 D
117 Rule US 1975 only - Feb 23 2:00 1:00 D
118 Rule US 1976 1986 - Apr lastSun 2:00 1:00 D
119 Rule US 1987 max - Apr Sun>=1 2:00 1:00 D
120 # <a href="http://thomas.loc.gov/cgi-bin/bdquery/z?d106:h.r.00177:">
122 # </a> (introduced 1999-01-06) would change April to March in the above rule.
124 # From Bob Devine (1988-01-28):
125 # ...Alaska (and Hawaii) had the timezone names changed in 1967.
127 # Pacific Standard Time(PST) -same-
128 # Yukon Standard Time(YST) -same-
129 # Central Alaska S.T. (CAT) Alaska-Hawaii St[an]dard Time (AHST)
130 # Nome Standard Time (NT) Bering Standard Time (BST)
132 # ...Alaska's timezone lines were redrawn in 1983 to give only 2 tz.
133 # The YST zone now covers nearly all of the state, AHST just part
134 # of the Aleutian islands. No DST.
136 # From Paul Eggert (1995-12-19):
137 # The tables below use `NST', not `NT', for Nome Standard Time.
138 # I invented `CAWT' for Central Alaska War Time.
140 # From U. S. Naval Observatory (1989-01-19):
141 # USA EASTERN 5 H BEHIND UTC NEW YORK, WASHINGTON
142 # USA EASTERN 4 H BEHIND UTC APR 3 - OCT 30
143 # USA CENTRAL 6 H BEHIND UTC CHICAGO, HOUSTON
144 # USA CENTRAL 5 H BEHIND UTC APR 3 - OCT 30
145 # USA MOUNTAIN 7 H BEHIND UTC DENVER
146 # USA MOUNTAIN 6 H BEHIND UTC APR 3 - OCT 30
147 # USA PACIFIC 8 H BEHIND UTC L.A., SAN FRANCISCO
148 # USA PACIFIC 7 H BEHIND UTC APR 3 - OCT 30
149 # USA ALASKA STD 9 H BEHIND UTC MOST OF ALASKA (AKST)
150 # USA ALASKA STD 8 H BEHIND UTC APR 3 - OCT 30 (AKDT)
151 # USA ALEUTIAN 10 H BEHIND UTC ISLANDS WEST OF 170W
152 # USA - " - 9 H BEHIND UTC APR 3 - OCT 30
153 # USA HAWAII 10 H BEHIND UTC
154 # USA BERING 11 H BEHIND UTC SAMOA, MIDWAY
156 # From Arthur David Olson (1989-01-21):
157 # The above dates are for 1988.
158 # Note the "AKST" and "AKDT" abbreviations, the claim that there's
159 # no DST in Samoa, and the claim that there is DST in Alaska and the
162 # From Arthur David Olson (1988-02-13):
163 # Legal standard time zone names, from United States Code (1982 Edition and
164 # Supplement III), Title 15, Chapter 6, Section 260 and forward. First, names
165 # up to 1967-04-01 (when most provisions of the Uniform Time Act of 1966
166 # took effect), as explained in sections 263 and 261:
168 # United States standard eastern time
169 # United States standard mountain time
170 # United States standard central time
171 # United States standard Pacific time
173 # United States standard Alaska time
175 # Next, names from 1967-04-01 until 1983-11-30 (the date for
176 # public law 98-181):
177 # Atlantic standard time
178 # eastern standard time
179 # central standard time
180 # mountain standard time
181 # Pacific standard time
182 # Yukon standard time
183 # Alaska-Hawaii standard time
184 # Bering standard time
185 # And after 1983-11-30:
186 # Atlantic standard time
187 # eastern standard time
188 # central standard time
189 # mountain standard time
190 # Pacific standard time
191 # Alaska standard time
192 # Hawaii-Aleutian standard time
193 # Samoa standard time
194 # The law doesn't give abbreviations.
196 # From Paul Eggert (2000-01-08), following a heads-up from Rives McDow:
197 # Public law 106-564 (2000-12-23) introduced the abbreviation
198 # "Chamorro Standard Time" for time in Guam and the Northern Marianas.
199 # See the file "australasia".
202 # US eastern time, represented by New York
204 # Connecticut, Delaware, District of Columbia, most of Florida,
205 # Georgia, southeast Indiana (Clark, Dearborn, Floyd, Harrison, and
206 # Ohio counties), eastern Kentucky, Maine, Maryland, Massachusetts,
207 # New Hampshire, New Jersey, New York, North Carolina, Ohio,
208 # Pennsylvania, Rhode Island, South Carolina, eastern Tennessee,
209 # Vermont, Virginia, West Virginia
211 # From Dave Cantor (2004-11-02):
212 # Early this summer I had the occasion to visit the Mount Washington
213 # Observatory weather station atop (of course!) Mount Washington [, NH]....
214 # One of the staff members said that the station was on Eastern Standard Time
215 # and didn't change their clocks for Daylight Saving ... so that their
216 # reports will always have times which are 5 hours behind UTC.
218 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER
219 Rule NYC 1920 only - Mar lastSun 2:00 1:00 D
220 Rule NYC 1920 only - Oct lastSun 2:00 0 S
221 Rule NYC 1921 1966 - Apr lastSun 2:00 1:00 D
222 Rule NYC 1921 1954 - Sep lastSun 2:00 0 S
223 Rule NYC 1955 1966 - Oct lastSun 2:00 0 S
224 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
225 Zone America/New_York -4:56:02 - LMT 1883 Nov 18 12:00
232 # US central time, represented by Chicago
234 # Alabama, Arkansas, Florida panhandle (Bay, Calhoun, Escambia,
235 # Gulf, Holmes, Jackson, Okaloosa, Santa Rosa, Walton, and
236 # Washington counties), Illinois, western Indiana
237 # (Gibson, Jasper, Lake, LaPorte, Newton, Porter, Posey, Spencer,
238 # Vanderburgh, and Warrick counties), Iowa, most of Kansas, western
239 # Kentucky, Louisiana, Minnesota, Mississippi, Missouri, eastern
240 # Nebraska, eastern North Dakota, Oklahoma, eastern South Dakota,
241 # western Tennessee, most of Texas, Wisconsin
243 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER
244 Rule Chicago 1920 only - Jun 13 2:00 1:00 D
245 Rule Chicago 1920 1921 - Oct lastSun 2:00 0 S
246 Rule Chicago 1921 only - Mar lastSun 2:00 1:00 D
247 Rule Chicago 1922 1966 - Apr lastSun 2:00 1:00 D
248 Rule Chicago 1922 1954 - Sep lastSun 2:00 0 S
249 Rule Chicago 1955 1966 - Oct lastSun 2:00 0 S
250 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
251 Zone America/Chicago -5:50:36 - LMT 1883 Nov 18 12:00
253 -6:00 Chicago C%sT 1936 Mar 1 2:00
254 -5:00 - EST 1936 Nov 15 2:00
255 -6:00 Chicago C%sT 1942
257 -6:00 Chicago C%sT 1967
259 # Oliver County, ND switched from mountain to central time on 1992-10-25.
260 Zone America/North_Dakota/Center -6:45:12 - LMT 1883 Nov 18 12:00
261 -7:00 US M%sT 1992 Oct 25 02:00
264 # US mountain time, represented by Denver
266 # Colorado, far western Kansas, Montana, western
267 # Nebraska, Nevada border (Jackpot, Owyhee, and Mountain City),
268 # New Mexico, southwestern North Dakota, far eastern Oregon,
269 # western South Dakota, far western Texas (El Paso County, Hudspeth County,
270 # and Pine Springs and Nickel Creek in Culberson County), Utah, Wyoming
272 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER
273 Rule Denver 1920 1921 - Mar lastSun 2:00 1:00 D
274 Rule Denver 1920 only - Oct lastSun 2:00 0 S
275 Rule Denver 1921 only - May 22 2:00 0 S
276 Rule Denver 1965 1966 - Apr lastSun 2:00 1:00 D
277 Rule Denver 1965 1966 - Oct lastSun 2:00 0 S
278 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
279 Zone America/Denver -6:59:56 - LMT 1883 Nov 18 12:00
281 -7:00 Denver M%sT 1942
283 -7:00 Denver M%sT 1967
286 # US Pacific time, represented by Los Angeles
288 # California, northern Idaho (Benewah, Bonner, Boundary, Clearwater,
289 # Idaho, Kootenai, Latah, Lewis, Nez Perce, and Shoshone counties),
290 # most of Nevada, most of Oregon, and Washington
292 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER
293 Rule CA 1948 only - Mar 14 2:00 1:00 D
294 Rule CA 1949 only - Jan 1 2:00 0 S
295 Rule CA 1950 1966 - Apr lastSun 2:00 1:00 D
296 Rule CA 1950 1961 - Sep lastSun 2:00 0 S
297 Rule CA 1962 1966 - Oct lastSun 2:00 0 S
298 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
299 Zone America/Los_Angeles -7:52:58 - LMT 1883 Nov 18 12:00
305 # AK%sT is the modern abbreviation for -9:00 per USNO.
307 # From Paul Eggert (2001-05-30):
308 # Howse writes that Alaska switched from the Julian to the Gregorian calendar,
309 # and from east-of-GMT to west-of-GMT days, when the US bought it from Russia.
310 # This was on 1867-10-18, a Friday; the previous day was 1867-10-06 Julian,
311 # also a Friday. Include only the time zone part of this transition,
312 # ignoring the switch from Julian to Gregorian, since we can't represent
313 # the Julian calendar.
315 # As far as we know, none of the exact locations mentioned below were
316 # permanently inhabited in 1867 by anyone using either calendar.
317 # (Yakutat was colonized by the Russians in 1799, but the settlement
318 # was destroyed in 1805 by a Yakutat-kon war party.) However, there
319 # were nearby inhabitants in some cases and for our purposes perhaps
320 # it's best to simply use the official transition.
322 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
323 Zone America/Juneau 15:02:19 - LMT 1867 Oct 18
324 -8:57:41 - LMT 1900 Aug 20 12:00
328 -8:00 US P%sT 1983 Oct 30 2:00
329 -9:00 US Y%sT 1983 Nov 30
331 Zone America/Yakutat 14:41:05 - LMT 1867 Oct 18
332 -9:18:55 - LMT 1900 Aug 20 12:00
336 -9:00 US Y%sT 1983 Nov 30
338 Zone America/Anchorage 14:00:24 - LMT 1867 Oct 18
339 -9:59:36 - LMT 1900 Aug 20 12:00
341 -10:00 US CAT/CAWT 1946
342 -10:00 - CAT 1967 Apr
344 -10:00 US AH%sT 1983 Oct 30 2:00
345 -9:00 US Y%sT 1983 Nov 30
347 Zone America/Nome 12:58:21 - LMT 1867 Oct 18
348 -11:01:38 - LMT 1900 Aug 20 12:00
351 -11:00 - NST 1967 Apr
353 -11:00 US B%sT 1983 Oct 30 2:00
354 -9:00 US Y%sT 1983 Nov 30
356 Zone America/Adak 12:13:21 - LMT 1867 Oct 18
357 -11:46:38 - LMT 1900 Aug 20 12:00
360 -11:00 - NST 1967 Apr
362 -11:00 US B%sT 1983 Oct 30 2:00
363 -10:00 US AH%sT 1983 Nov 30
365 # The following switches don't quite make our 1970 cutoff.
367 # Shanks writes that part of southwest Alaska (e.g. Aniak)
368 # switched from -11:00 to -10:00 on 1968-09-22 at 02:00,
369 # and another part (e.g. Akiak) made the same switch five weeks later.
371 # From David Flater (2004-11-09):
372 # In e-mail, 2004-11-02, Ray Hudson, historian/liaison to the Unalaska
373 # Historic Preservation Commission, provided this information, which
374 # suggests that Unalaska deviated from statutory time from early 1967
375 # possibly until 1983:
377 # Minutes of the Unalaska City Council Meeting, January 10, 1967:
378 # "Except for St. Paul and Akutan, Unalaska is the only important
379 # location not on Alaska Standard Time. The following resolution was
380 # made by William Robinson and seconded by Henry Swanson: Be it
381 # resolved that the City of Unalaska hereby goes to Alaska Standard
382 # Time as of midnight Friday, January 13, 1967 (1 A.M. Saturday,
383 # January 14, Alaska Standard Time.) This resolution was passed with
384 # three votes for and one against."
388 # From Arthur David Olson:
389 # And then there's Hawaii.
390 # DST was observed for one day in 1933;
391 # standard time was changed by half an hour in 1947;
392 # it's always standard as of 1986.
395 # Shanks says the 1933 experiment lasted for three weeks. Go with Shanks.
397 Zone Pacific/Honolulu -10:31:26 - LMT 1900 Jan 1 12:00
398 -10:30 - HST 1933 Apr 30 2:00
399 -10:30 1:00 HDT 1933 May 21 2:00
400 -10:30 US H%sT 1947 Jun 8 2:00
403 # Now we turn to US areas that have diverged from the consensus since 1970.
405 # Arizona mostly uses MST.
407 # From Paul Eggert (2002-10-20):
409 # The information in the rest of this paragraph is derived from the
410 # <a href="http://www.dlapr.lib.az.us/links/daylight.htm">
411 # Daylight Saving Time web page (2002-01-23)</a> maintained by the
412 # Arizona State Library, Archives and Public Records.
413 # Between 1944-01-01 and 1944-04-01 the State of Arizona used standard
414 # time, but by federal law railroads, airlines, bus lines, military
415 # personnel, and some engaged in interstate commerce continued to
416 # observe war (i.e., daylight saving) time. The 1944-03-17 Phoenix
417 # Gazette says that was the date the law changed, and that 04-01 was
418 # the date the state's clocks would change. In 1945 the State of
419 # Arizona used standard time all year, again with exceptions only as
420 # mandated by federal law. Arizona observed DST in 1967, but Arizona
421 # Laws 1968, ch. 183 (effective 1968-03-21) repealed DST.
423 # Shanks says the 1944 experiment came to an end on 1944-03-17.
424 # Go with the Arizona State Library instead.
426 Zone America/Phoenix -7:28:18 - LMT 1883 Nov 18 12:00
427 -7:00 US M%sT 1944 Jan 1 00:01
428 -7:00 - MST 1944 Apr 1 00:01
429 -7:00 US M%sT 1944 Oct 1 00:01
431 -7:00 US M%sT 1968 Mar 21
433 # From Arthur David Olson (1988-02-13):
434 # A writer from the Inter Tribal Council of Arizona, Inc.,
435 # notes in private correspondence dated 1987-12-28 that "Presently, only the
436 # Navajo Nation participates in the Daylight Saving Time policy, due to its
437 # large size and location in three states." (The "only" means that other
438 # tribal nations don't use DST.)
440 Link America/Denver America/Shiprock
442 # Southern Idaho (Ada, Adams, Bannock, Bear Lake, Bingham, Blaine,
443 # Boise, Bonneville, Butte, Camas, Canyon, Caribou, Cassia, Clark,
444 # Custer, Elmore, Franklin, Fremont, Gem, Gooding, Jefferson, Jerome,
445 # Lemhi, Lincoln, Madison, Minidoka, Oneida, Owyhee, Payette, Power,
446 # Teton, Twin Falls, Valley, Washington counties) and eastern Oregon
447 # switched four weeks late in 1974.
449 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
450 Zone America/Boise -7:44:49 - LMT 1883 Nov 18 12:00
451 -8:00 US P%sT 1923 May 13 2:00
453 -7:00 - MST 1974 Feb 3 2:00
458 # For a map of Indiana's time zone regions, see:
459 # <a href="http://www.mccsc.edu/time.html">
460 # What time is it in Indiana?
463 # From Paul Eggert (1995-12-19):
464 # Indiana generally observes either EST all year, or CST/CDT,
465 # but areas near Cincinnati and Louisville use those cities' timekeeping
466 # and in 1969 and 1970 the whole state observed daylight time;
467 # and there are other exceptions as noted below.
468 # Shanks partitions Indiana into 345 regions, each with its own time history,
469 # and writes ``Even newspaper reports present contradictory information.''
470 # Fortunately, most of the complexity occurred before our cutoff date of 1970.
472 # Since 1970, EST-only Indiana has been like America/Indianapolis,
473 # with exceptions noted below for Crawford, Starke, and Switzerland counties.
474 # The parts of Indiana not listed below have been like America/Chicago,
475 # America/Louisville, or America/New_York.
477 # Other than Indianapolis, the Indiana place names are so nondescript
478 # that they would be ambiguous if we left them at the `America' level.
479 # So we reluctantly put them all in a subdirectory `America/Indiana'.
481 # Most of EST-only Indiana last observed DST in 1970.
483 # From Paul Eggert (2001-03-06), following a tip by Markus Kuhn:
484 # Pam Belluck reported in the New York Times (2001-01-31) that the
485 # Indiana Legislature is considering a bill to adopt DST statewide.
486 # Her article mentioned Vevay, whose post office observes a different
487 # time zone from Danner's Hardware across the street.
489 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER
490 Rule Indianapolis 1941 only - Jun 22 2:00 1:00 D
491 Rule Indianapolis 1941 1954 - Sep lastSun 2:00 0 S
492 Rule Indianapolis 1946 1954 - Apr lastSun 2:00 1:00 D
493 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
494 Zone America/Indianapolis -5:44:38 - LMT 1883 Nov 18 12:00
496 -6:00 Indianapolis C%sT 1942
498 -6:00 Indianapolis C%sT 1955 Apr 24 2:00
499 -5:00 - EST 1957 Sep 29 2:00
500 -6:00 - CST 1958 Apr 27 2:00
504 Link America/Indianapolis America/Indiana/Indianapolis
506 # Part of Crawford County, Indiana, last observed DST in 1975,
507 # and left its clocks alone in 1974.
508 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER
509 Rule Marengo 1951 only - Apr lastSun 2:00 1:00 D
510 Rule Marengo 1951 only - Sep lastSun 2:00 0 S
511 Rule Marengo 1954 1960 - Apr lastSun 2:00 1:00 D
512 Rule Marengo 1954 1960 - Sep lastSun 2:00 0 S
513 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
514 Zone America/Indiana/Marengo -5:45:23 - LMT 1883 Nov 18 12:00
516 -6:00 Marengo C%sT 1961 Apr 30 2:00
518 -5:00 US E%sT 1974 Jan 6 2:00
519 -6:00 1:00 CDT 1974 Oct 27 2:00
523 # Starke County, Indiana
524 # From Arthur David Olson (1991-10-28):
525 # An article on page A3 of the Sunday, 1991-10-27 Washington Post
526 # notes that Starke County switched from Central time to Eastern time as of
528 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER
529 Rule Starke 1947 1961 - Apr lastSun 2:00 1:00 D
530 Rule Starke 1947 1954 - Sep lastSun 2:00 0 S
531 Rule Starke 1955 1956 - Oct lastSun 2:00 0 S
532 Rule Starke 1957 1958 - Sep lastSun 2:00 0 S
533 Rule Starke 1959 1961 - Oct lastSun 2:00 0 S
534 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
535 Zone America/Indiana/Knox -5:46:30 - LMT 1883 Nov 18 12:00
537 -6:00 Starke C%sT 1962 Apr 29 2:00
538 -5:00 - EST 1963 Oct 27 2:00
539 -6:00 US C%sT 1991 Oct 27 2:00
542 # Switzerland County, Indiana, last observed DST in 1972.
543 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
544 Zone America/Indiana/Vevay -5:40:16 - LMT 1883 Nov 18 12:00
545 -6:00 US C%sT 1954 Apr 25 2:00
550 # Part of Kentucky left its clocks alone in 1974.
551 # This also includes a part of Indiana immediately adjacent to Louisville.
552 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER
553 Rule Louisville 1921 only - May 1 2:00 1:00 D
554 Rule Louisville 1921 only - Sep 1 2:00 0 S
555 Rule Louisville 1941 1961 - Apr lastSun 2:00 1:00 D
556 Rule Louisville 1941 only - Sep lastSun 2:00 0 S
557 Rule Louisville 1946 only - Jun 2 2:00 0 S
558 Rule Louisville 1950 1955 - Sep lastSun 2:00 0 S
559 Rule Louisville 1956 1960 - Oct lastSun 2:00 0 S
560 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
561 Zone America/Louisville -5:43:02 - LMT 1883 Nov 18 12:00
563 -6:00 Louisville C%sT 1942
565 -6:00 Louisville C%sT 1961 Jul 23 2:00
567 -5:00 US E%sT 1974 Jan 6 2:00
568 -6:00 1:00 CDT 1974 Oct 27 2:00
570 Link America/Louisville America/Kentucky/Louisville
572 # Wayne, Clinton, and Russell Counties, Kentucky
575 # <a href="http://www.lake-cumberland.com/life/archive/news990129time.shtml">
576 # Lake Cumberland LIFE
577 # </a> (1999-01-29) via WKYM-101.7:
578 # Clinton County has joined Wayne County in asking the DoT to change from
579 # the Central to the Eastern time zone.... The Wayne County government made
580 # the same request in December. And while Russell County officials have not
581 # taken action, the majority of respondents to a poll conducted there in
582 # August indicated they would like to change to "fast time" also.
583 # The three Lake Cumberland counties are the farthest east of any U.S.
584 # location in the Central time zone.
586 # From Rich Wales (2000-08-29):
587 # After prolonged debate, and despite continuing deep differences of opinion,
588 # Wayne County (central Kentucky) is switching from Central (-0600) to Eastern
589 # (-0500) time. They won't "fall back" this year. See Sara Shipley,
590 # The difference an hour makes, Nando Times (2000-08-29 15:33 -0400).
592 # From Paul Eggert (2001-07-16):
593 # The final rule was published in the
594 # <a href="http://frwebgate.access.gpo.gov/cgi-bin/getdoc.cgi?dbname=2000_register&docid=fr17au00-22">
595 # Federal Register 65, 160 (2000-08-17), page 50154-50158.
598 Zone America/Kentucky/Monticello -5:39:24 - LMT 1883 Nov 18 12:00
601 -6:00 US C%sT 2000 Oct 29 2:00
605 # From Rives McDow (2000-08-30):
606 # Here ... are all the changes in the US since 1985.
607 # Kearny County, KS (put all of county on central;
608 # previously split between MST and CST) ... 1990-10
609 # Starke County, IN (from CST to EST) ... 1991-10
610 # Oliver County, ND (from MST to CST) ... 1992-10
611 # West Wendover, NV (from PST TO MST) ... 1999-10
612 # Wayne County, KY (from CST to EST) ... 2000-10
614 # From Paul Eggert (2001-07-17):
615 # We don't know where the line used to be within Kearny County, KS,
616 # so omit that change for now.
617 # See America/Indiana/Knox for the Starke County, IN change.
618 # See America/North_Dakota/Center for the Oliver County, ND change.
619 # West Wendover, NV officially switched from Pacific to mountain time on
620 # 1999-10-31. See the
621 # <a href="http://frwebgate.access.gpo.gov/cgi-bin/getdoc.cgi?dbname=1999_register&docid=fr21oc99-15">
622 # Federal Register 64, 203 (1999-10-21), page 56705-56707.
624 # However, the Federal Register says that West Wendover already operated
625 # on mountain time, and the rule merely made this official;
626 # hence a separate tz entry is not needed.
630 # From Bob Devine (1988-01-28):
631 # Michigan didn't observe DST from 1968 to 1973.
633 # From Paul Eggert (1999-03-31):
634 # Shanks writes that Michigan started using standard time on 1885-09-18,
635 # but Howse writes (pp 124-125, referring to Popular Astronomy, 1901-01)
638 # local time until 1900 when the City Council decreed that clocks should
639 # be put back twenty-eight minutes to Central Standard Time. Half the
640 # city obeyed, half refused. After considerable debate, the decision
641 # was rescinded and the city reverted to Sun time. A derisive offer to
642 # erect a sundial in front of the city hall was referred to the
643 # Committee on Sewers. Then, in 1905, Central time was adopted
646 # This story is too entertaining to be false, so go with Howse over Shanks.
648 # From Paul Eggert (2001-03-06):
649 # Garland (1927) writes ``Cleveland and Detroit advanced their clocks
650 # one hour in 1914.'' This change is not in Shanks. We have no more
651 # info, so omit this for now.
653 # Most of Michigan observed DST from 1973 on, but was a bit late in 1975.
654 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER
655 Rule Detroit 1948 only - Apr lastSun 2:00 1:00 D
656 Rule Detroit 1948 only - Sep lastSun 2:00 0 S
657 Rule Detroit 1967 only - Jun 14 2:00 1:00 D
658 Rule Detroit 1967 only - Oct lastSun 2:00 0 S
659 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
660 Zone America/Detroit -5:32:11 - LMT 1905
661 -6:00 - CST 1915 May 15 2:00
664 -5:00 Detroit E%sT 1973
666 -5:00 - EST 1975 Apr 27 2:00
669 # The Michigan border with Wisconsin switched from EST to CST/CDT in 1973.
670 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER
671 Rule Menominee 1946 only - Apr lastSun 2:00 1:00 D
672 Rule Menominee 1946 only - Sep lastSun 2:00 0 S
673 Rule Menominee 1966 only - Apr lastSun 2:00 1:00 D
674 Rule Menominee 1966 only - Oct lastSun 2:00 0 S
675 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
676 Zone America/Menominee -5:50:27 - LMT 1885 Sep 18 12:00
678 -6:00 Menominee C%sT 1969 Apr 27 2:00
679 -5:00 - EST 1973 Apr 29 2:00
683 # administered by the US Fish and Wildlife Service
684 # claimed by US under the provisions of the 1856 Guano Islands Act
685 # also claimed by Haiti
686 # occupied 1857/1900 by the Navassa Phosphate Co
687 # US lighthouse 1917/1996-09
688 # currently uninhabited
689 # see Mark Fineman, ``An Isle Rich in Guano and Discord'',
690 # _Los Angeles Times_ (1998-11-10), A1, A10; it cites
691 # Jimmy Skaggs, _The Great Guano Rush_ (1994).
693 # Old names, for S5 users
695 # Link LINK-FROM LINK-TO
696 Link America/New_York EST5EDT
697 Link America/Chicago CST6CDT
698 Link America/Denver MST7MDT
699 Link America/Los_Angeles PST8PDT
700 Link America/Indianapolis EST
701 Link America/Phoenix MST
702 Link Pacific/Honolulu HST
704 ################################################################################
707 # From Paul Eggert <eggert@twinsun.com> (1999-10-29):
708 # A good source for time zone historical data outside the US is
709 # Thomas G. Shanks, The International Atlas (5th edition),
710 # San Diego: ACS Publications, Inc. (1999).
712 # Gwillim Law writes that a good source
713 # for recent time zone data is the International Air Transport
714 # Association's Standard Schedules Information Manual (IATA SSIM),
715 # published semiannually. Law sent in several helpful summaries
716 # of the IATA's data after 1990.
718 # Except where otherwise noted, Shanks is the source for entries through 1990,
719 # and IATA SSIM is the source for entries after 1990.
721 # Other sources occasionally used include:
723 # Edward W. Whitman, World Time Differences,
724 # Whitman Publishing Co, 2 Niagara Av, Ealing, London (undated),
725 # which I found in the UCLA library.
727 # <a href="http://www.pettswoodvillage.co.uk/Daylight_Savings_William_Willett.pdf">
728 # William Willett, The Waste of Daylight, 19th edition
731 # See the `europe' file for Greenland.
735 # From Alain LaBont<e'> <ALB@immedia.ca> (1994-11-14):
736 # I post here the time zone abbreviations standardized in Canada
737 # for both English and French in the CAN/CSA-Z234.4-89 standard....
739 # UTC Standard time Daylight savings time
740 # offset French English French English
751 # HN: Heure Normale ST: Standard Time
752 # HA: Heure Avanc<e'>e DT: Daylight saving Time
754 # A: de l'Atlantique Atlantic
755 # C: du Centre Central
756 # E: de l'Est Eastern
759 # P: du Pacifique Pacific
764 # From Paul Eggert <eggert@twinsun.com> (1994-11-22):
765 # Alas, this sort of thing must be handled by localization software.
767 # Unless otherwise specified, the data for Canada are all from Shanks.
769 # From Paul Eggert (2000-10-02):
770 # H. David Matthews and Mary Vincent's map
771 # <a href="http://www.canadiangeographic.ca/SO98/geomap.htm">
772 # "It's about TIME", _Canadian Geographic_ (September-October 1998)
773 # </a> contains detailed boundaries for regions observing nonstandard
774 # time and daylight saving time arrangements in Canada circa 1998.
776 # INMS, the Institute for National Measurement Standards in Ottawa, has
777 # <a href="http://www.nrc.ca/inms/time/tze.html">
778 # information about standard and daylight saving time zones in Canada.
779 # </a> (updated periodically).
780 # Its unofficial information is often taken from Matthews and Vincent.
782 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
783 Rule Canada 1918 only - Apr 14 2:00 1:00 D
784 Rule Canada 1918 only - Oct 31 2:00 0 S
785 Rule Canada 1942 only - Feb 9 2:00 1:00 W # War
786 Rule Canada 1945 only - Aug 14 23:00u 1:00 P # Peace
787 Rule Canada 1945 only - Sep 30 2:00 0 S
788 Rule Canada 1974 1986 - Apr lastSun 2:00 1:00 D
789 Rule Canada 1974 max - Oct lastSun 2:00 0 S
790 Rule Canada 1987 max - Apr Sun>=1 2:00 1:00 D
793 # Newfoundland (and far southeast Labrador)
795 # From Paul Eggert (2000-10-02):
796 # Matthews and Vincent (1998) write that Labrador should use NST/NDT,
797 # but the only part of Labrador that follows the rules is the
798 # southeast corner, including Port Hope Simpson and Mary's Harbour,
799 # but excluding, say, Black Tickle.
801 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
802 Rule StJohns 1917 only - Apr 8 2:00 1:00 D
803 Rule StJohns 1917 only - Sep 17 2:00 0 S
804 # Whitman gives 1919 Apr 5 and 1920 Apr 5; go with Shanks.
805 Rule StJohns 1919 only - May 5 23:00 1:00 D
806 Rule StJohns 1919 only - Aug 12 23:00 0 S
807 # For 1931-1935 Whitman gives Apr same date; go with Shanks.
808 Rule StJohns 1920 1935 - May Sun>=1 23:00 1:00 D
809 Rule StJohns 1920 1935 - Oct lastSun 23:00 0 S
810 # For 1936-1941 Whitman gives May Sun>=8 and Oct Sun>=1; go with Shanks.
811 Rule StJohns 1936 1941 - May Mon>=9 0:00 1:00 D
812 Rule StJohns 1936 1941 - Oct Mon>=2 0:00 0 S
813 # Whitman gives the following transitions:
814 # 1942 03-01/12-31, 1943 05-30/09-05, 1944 07-10/09-02, 1945 01-01/10-07
815 # but go with Shanks and assume they used Canadian rules.
816 # For 1946-9 Whitman gives May 5,4,9,1 - Oct 1,5,3,2, and for 1950 he gives
817 # Apr 30 - Sep 24; go with Shanks.
818 Rule StJohns 1946 1950 - May Sun>=8 2:00 1:00 D
819 Rule StJohns 1946 1950 - Oct Sun>=2 2:00 0 S
820 Rule StJohns 1951 1986 - Apr lastSun 2:00 1:00 D
821 Rule StJohns 1951 1959 - Sep lastSun 2:00 0 S
822 Rule StJohns 1960 1986 - Oct lastSun 2:00 0 S
823 # From Paul Eggert (2000-10-02):
824 # INMS (2000-09-12) says that, since 1988 at least, Newfoundland switches
825 # at 00:01 local time. For now, assume it started in 1987.
826 Rule StJohns 1987 only - Apr Sun>=1 0:01 1:00 D
827 Rule StJohns 1987 max - Oct lastSun 0:01 0 S
828 Rule StJohns 1988 only - Apr Sun>=1 0:01 2:00 DD
829 Rule StJohns 1989 max - Apr Sun>=1 0:01 1:00 D
830 # St John's has an apostrophe, but Posix file names can't have apostrophes.
831 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
832 Zone America/St_Johns -3:30:52 - LMT 1884
833 -3:30:52 StJohns N%sT 1918
834 -3:30:52 Canada N%sT 1919
835 -3:30:52 StJohns N%sT 1935 Mar 30
836 -3:30 StJohns N%sT 1942 May 11
837 -3:30 Canada N%sT 1946
840 # most of east Labrador
842 # The name `Happy Valley-Goose Bay' is too long; use `Goose Bay'.
843 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
844 Zone America/Goose_Bay -4:01:40 - LMT 1884 # Happy Valley-Goose Bay
846 -3:30:52 Canada N%sT 1919
847 -3:30:52 - NST 1935 Mar 30
849 -3:30 StJohns N%sT 1942 May 11
850 -3:30 Canada N%sT 1946
851 -3:30 StJohns N%sT 1966 Mar 15 2:00
855 # west Labrador, New Brunswick, Nova Scotia, Prince Edward I
857 # From Paul Eggert (1996-06-12):
858 # Shanks writes that since 1970 most of this region has been like Halifax.
859 # Many locales did not observe peacetime DST until 1972;
860 # Glace Bay, NS is the largest that we know of.
861 # Shanks also writes that Liverpool, NS was the only town in Canada to observe
862 # DST in 1971 but not 1970; for now we'll assume this is a typo.
864 # From Paul Eggert (2000-10-02):
865 # INMS (2000-09-12) says that, since 1988 at least, New Brunswick switches
866 # at 00:01 local time. FIXME: verify and create a new Zone for this.
869 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
870 Rule Halifax 1916 only - Apr 1 0:00 1:00 D
871 Rule Halifax 1916 only - Oct 1 0:00 0 S
872 Rule Halifax 1920 only - May 9 0:00 1:00 D
873 Rule Halifax 1920 only - Aug 29 0:00 0 S
874 Rule Halifax 1921 only - May 6 0:00 1:00 D
875 Rule Halifax 1921 1922 - Sep 5 0:00 0 S
876 Rule Halifax 1922 only - Apr 30 0:00 1:00 D
877 Rule Halifax 1923 1925 - May Sun>=1 0:00 1:00 D
878 Rule Halifax 1923 only - Sep 4 0:00 0 S
879 Rule Halifax 1924 only - Sep 15 0:00 0 S
880 Rule Halifax 1925 only - Sep 28 0:00 0 S
881 Rule Halifax 1926 only - May 16 0:00 1:00 D
882 Rule Halifax 1926 only - Sep 13 0:00 0 S
883 Rule Halifax 1927 only - May 1 0:00 1:00 D
884 Rule Halifax 1927 only - Sep 26 0:00 0 S
885 Rule Halifax 1928 1931 - May Sun>=8 0:00 1:00 D
886 Rule Halifax 1928 only - Sep 9 0:00 0 S
887 Rule Halifax 1929 only - Sep 3 0:00 0 S
888 Rule Halifax 1930 only - Sep 15 0:00 0 S
889 Rule Halifax 1931 1932 - Sep Mon>=24 0:00 0 S
890 Rule Halifax 1932 only - May 1 0:00 1:00 D
891 Rule Halifax 1933 only - Apr 30 0:00 1:00 D
892 Rule Halifax 1933 only - Oct 2 0:00 0 S
893 Rule Halifax 1934 only - May 20 0:00 1:00 D
894 Rule Halifax 1934 only - Sep 16 0:00 0 S
895 Rule Halifax 1935 only - Jun 2 0:00 1:00 D
896 Rule Halifax 1935 only - Sep 30 0:00 0 S
897 Rule Halifax 1936 only - Jun 1 0:00 1:00 D
898 Rule Halifax 1936 only - Sep 14 0:00 0 S
899 Rule Halifax 1937 1938 - May Sun>=1 0:00 1:00 D
900 Rule Halifax 1937 1941 - Sep Mon>=24 0:00 0 S
901 Rule Halifax 1939 only - May 28 0:00 1:00 D
902 Rule Halifax 1940 1941 - May Sun>=1 0:00 1:00 D
903 Rule Halifax 1946 1949 - Sep lastSun 2:00 0 S
904 Rule Halifax 1946 1949 - Apr lastSun 2:00 1:00 D
905 Rule Halifax 1951 1954 - Sep lastSun 2:00 0 S
906 Rule Halifax 1951 1954 - Apr lastSun 2:00 1:00 D
907 Rule Halifax 1956 1959 - Sep lastSun 2:00 0 S
908 Rule Halifax 1956 1959 - Apr lastSun 2:00 1:00 D
909 Rule Halifax 1962 1973 - Apr lastSun 2:00 1:00 D
910 Rule Halifax 1962 1973 - Oct lastSun 2:00 0 S
911 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
912 Zone America/Halifax -4:14:24 - LMT 1902 Jun 15
913 -4:00 Halifax A%sT 1918
914 -4:00 Canada A%sT 1919
915 -4:00 Halifax A%sT 1942 Feb 9 2:00s
916 -4:00 Canada A%sT 1946
917 -4:00 Halifax A%sT 1974
919 Zone America/Glace_Bay -3:59:48 - LMT 1902 Jun 15
920 -4:00 Canada A%sT 1953
921 -4:00 Halifax A%sT 1954
923 -4:00 Halifax A%sT 1974
929 # From Paul Eggert (1996-06-12):
930 # Shanks writes that since 1970 most of Ontario has been like Toronto,
931 # and most of Quebec has been like Montreal.
932 # Thunder Bay skipped DST in 1973.
933 # Many smaller locales did not observe peacetime DST until 1974;
934 # Nipigon (EST) and Rainy River (CST) are the largest that we know of.
935 # Far west Ontario is like Winnipeg; far east Quebec is like Halifax.
937 # From Mark Brader (2003-07-26):
938 # [According to the Toronto Star] Orillia, Ontario, adopted DST
939 # effective Saturday, 1912-06-22, 22:00; the article mentions that
940 # Port Arthur (now part of Thunder Bay, Ontario) as well as Moose Jaw
941 # have already done so. In Orillia DST was to run until Saturday,
942 # 1912-08-31 (no time mentioned), but it was met with considerable
943 # hostility from certain segments of the public, and was revoked after
944 # only two weeks -- I copied it as Saturday, 1912-07-07, 22:00, but
945 # presumably that should be -07-06. (1912-06-19, -07-12; also letters
948 # Kenora, Ontario, was to abandon DST on 1914-06-01 (-05-21).
950 # From Paul Eggert (1997-10-17):
951 # Mark Brader writes that an article in the 1997-10-14 Toronto Star
952 # says that Atikokan, Ontario currently does not observe DST,
953 # but will vote on 11-10 whether to use EST/EDT.
954 # He also writes that the
955 # <a href="http://www.gov.on.ca/MBS/english/publications/statregs/conttext.html">
956 # Ontario Time Act (1990, Chapter T.9)
958 # says that Ontario east of 90W uses EST/EDT, and west of 90W uses CST/CDT.
959 # Officially Atikokan is therefore on CST/CDT, and most likely this report
960 # concerns a non-official time observed as a matter of local practice.
961 # For what it's worth, Shanks says that Atikokan has agreed with
962 # Rainy River ever since standard time was introduced.
964 # From Paul Eggert (2000-10-02):
965 # Matthews and Vincent (1998) write that Atikokan, Pickle Lake, and
966 # New Osnaburgh observe CST all year, that Big Trout Lake observes
967 # CST/CDT, and that Upsala and Shebandowan observe EST/EDT, all in
968 # violation of the official Ontario rules.
969 # They also write that Quebec east of the -63 meridian is supposed to
970 # observe AST, but residents as far east as Natashquan use EST/EDT,
971 # and residents east of Natashquan use AST.
972 # We probably need Zones for far east Quebec and for Atikokan,
973 # but we don't know when their practices started.
975 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
976 Rule Mont 1917 only - Mar 25 2:00 1:00 D
977 Rule Mont 1917 only - Apr 24 0:00 0 S
978 Rule Mont 1919 only - Mar 31 2:30 1:00 D
979 Rule Mont 1919 only - Oct 25 2:30 0 S
980 Rule Mont 1920 only - May 2 2:30 1:00 D
981 Rule Mont 1920 1922 - Oct Sun>=1 2:30 0 S
982 Rule Mont 1921 only - May 1 2:00 1:00 D
983 Rule Mont 1922 only - Apr 30 2:00 1:00 D
984 Rule Mont 1924 only - May 17 2:00 1:00 D
985 Rule Mont 1924 1926 - Sep lastSun 2:30 0 S
986 Rule Mont 1925 1926 - May Sun>=1 2:00 1:00 D
987 # The 1927-to-1937 rules can be expressed more simply as
988 # Rule Mont 1927 1937 - Apr lastSat 24:00 1:00 D
989 # Rule Mont 1927 1937 - Sep lastSat 24:00 0 S
990 # The rules below avoid use of 24:00
991 # (which pre-1998 versions of zic cannot handle).
992 Rule Mont 1927 only - May 1 0:00 1:00 D
993 Rule Mont 1927 1932 - Sep lastSun 0:00 0 S
994 Rule Mont 1928 1931 - Apr lastSun 0:00 1:00 D
995 Rule Mont 1932 only - May 1 0:00 1:00 D
996 Rule Mont 1933 1940 - Apr lastSun 0:00 1:00 D
997 Rule Mont 1933 only - Oct 1 0:00 0 S
998 Rule Mont 1934 1939 - Sep lastSun 0:00 0 S
999 Rule Mont 1946 1973 - Apr lastSun 2:00 1:00 D
1000 Rule Mont 1945 1948 - Sep lastSun 2:00 0 S
1001 Rule Mont 1949 1950 - Oct lastSun 2:00 0 S
1002 Rule Mont 1951 1956 - Sep lastSun 2:00 0 S
1003 Rule Mont 1957 1973 - Oct lastSun 2:00 0 S
1005 Rule Toronto 1919 only - Mar 30 23:30 1:00 D
1006 Rule Toronto 1919 only - Oct 26 0:00 0 S
1007 Rule Toronto 1920 only - May 2 2:00 1:00 D
1008 Rule Toronto 1920 only - Sep 26 0:00 0 S
1009 Rule Toronto 1921 only - May 15 2:00 1:00 D
1010 Rule Toronto 1921 only - Sep 15 2:00 0 S
1011 Rule Toronto 1922 1923 - May Sun>=8 2:00 1:00 D
1012 # Shanks says 1923-09-19; assume it's a typo and that "-16" was meant.
1013 Rule Toronto 1922 1926 - Sep Sun>=15 2:00 0 S
1014 Rule Toronto 1924 1927 - May Sun>=1 2:00 1:00 D
1015 # The 1927-to-1939 rules can be expressed more simply as
1016 # Rule Toronto 1927 1937 - Sep Sun>=25 2:00 0 S
1017 # Rule Toronto 1928 1937 - Apr Sun>=25 2:00 1:00 D
1018 # Rule Toronto 1938 1940 - Apr lastSun 2:00 1:00 D
1019 # Rule Toronto 1938 1939 - Sep lastSun 2:00 0 S
1020 # The rules below avoid use of Sun>=25
1021 # (which pre-2004 versions of zic cannot handle).
1022 Rule Toronto 1927 1932 - Sep lastSun 2:00 0 S
1023 Rule Toronto 1928 1931 - Apr lastSun 2:00 1:00 D
1024 Rule Toronto 1932 only - May 1 2:00 1:00 D
1025 Rule Toronto 1933 1940 - Apr lastSun 2:00 1:00 D
1026 Rule Toronto 1933 only - Oct 1 2:00 0 S
1027 Rule Toronto 1934 1939 - Sep lastSun 2:00 0 S
1028 Rule Toronto 1945 1946 - Sep lastSun 2:00 0 S
1029 Rule Toronto 1946 only - Apr lastSun 2:00 1:00 D
1030 Rule Toronto 1947 1949 - Apr lastSun 0:00 1:00 D
1031 Rule Toronto 1947 1948 - Sep lastSun 0:00 0 S
1032 Rule Toronto 1949 only - Nov lastSun 0:00 0 S
1033 Rule Toronto 1950 1973 - Apr lastSun 2:00 1:00 D
1034 Rule Toronto 1950 only - Nov lastSun 2:00 0 S
1035 Rule Toronto 1951 1956 - Sep lastSun 2:00 0 S
1036 # Shanks says Toronto ended DST a week early in 1971, namely on 1971-10-24,
1037 # but Mark Brader wrote (2003-05-31) that he checked the 1971-10-30 issue
1038 # of the Toronto Star, and it said that DST ended 1971-10-31 as usual.
1039 Rule Toronto 1957 1973 - Oct lastSun 2:00 0 S
1041 # From Paul Eggert (2003-07-27):
1042 # Willett (1914-03) writes (p. 17) "In the Cities of Fort William, and
1043 # Port Arthur, Ontario, the principle of the Bill has been in
1044 # operation for the past three years, and in the City of Moose Jaw,
1045 # Saskatchewan, for one year."
1047 # From David Bryan via Tory Tronrud, Director/Curator,
1048 # Thunder Bay Museum (2003-11-12):
1049 # There is some suggestion, however, that, by-law or not, daylight
1050 # savings time was being practiced in Fort William and Port Arthur
1051 # before 1909.... [I]n 1910, the line between the Eastern and Central
1052 # Time Zones was permanently moved about two hundred miles west to
1053 # include the Thunder Bay area.... When Canada adopted daylight
1054 # savings time in 1916, Fort William and Port Arthur, having done so
1055 # already, did not change their clocks.... During the Second World
1056 # War,... [t]he cities agreed to implement DST during the summer
1057 # months for the remainder of the war years.
1059 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1060 Zone America/Montreal -4:54:16 - LMT 1884
1061 -5:00 Mont E%sT 1918
1062 -5:00 Canada E%sT 1919
1063 -5:00 Mont E%sT 1942 Feb 9 2:00s
1064 -5:00 Canada E%sT 1946
1065 -5:00 Mont E%sT 1974
1067 Zone America/Toronto -5:17:32 - LMT 1895
1068 -5:00 Canada E%sT 1919
1069 -5:00 Toronto E%sT 1942 Feb 9 2:00s
1070 -5:00 Canada E%sT 1946
1071 -5:00 Toronto E%sT 1974
1073 Zone America/Thunder_Bay -5:57:00 - LMT 1895
1076 -5:00 Canada E%sT 1970
1077 -5:00 Mont E%sT 1973
1080 Zone America/Nipigon -5:53:04 - LMT 1895
1081 -5:00 Canada E%sT 1940 Sep 29
1082 -5:00 1:00 EDT 1942 Feb 9 2:00s
1084 Zone America/Rainy_River -6:17:56 - LMT 1895
1085 -6:00 Canada C%sT 1940 Sep 29
1086 -6:00 1:00 CDT 1942 Feb 9 2:00s
1092 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
1093 Rule Winn 1916 only - Apr 23 0:00 1:00 D
1094 Rule Winn 1916 only - Sep 17 0:00 0 S
1095 Rule Winn 1918 only - Apr 14 2:00 1:00 D
1096 Rule Winn 1918 only - Oct 31 2:00 0 S
1097 Rule Winn 1937 only - May 16 2:00 1:00 D
1098 Rule Winn 1937 only - Sep 26 2:00 0 S
1099 Rule Winn 1942 only - Feb 9 2:00 1:00 W # War
1100 Rule Winn 1945 only - Aug 14 23:00u 1:00 P # Peace
1101 Rule Winn 1945 only - Sep lastSun 2:00 0 S
1102 Rule Winn 1946 only - May 12 2:00 1:00 D
1103 Rule Winn 1946 only - Oct 13 2:00 0 S
1104 Rule Winn 1947 1949 - Apr lastSun 2:00 1:00 D
1105 Rule Winn 1947 1949 - Sep lastSun 2:00 0 S
1106 Rule Winn 1950 only - May 1 2:00 1:00 D
1107 Rule Winn 1950 only - Sep 30 2:00 0 S
1108 Rule Winn 1951 1960 - Apr lastSun 2:00 1:00 D
1109 Rule Winn 1951 1958 - Sep lastSun 2:00 0 S
1110 Rule Winn 1959 only - Oct lastSun 2:00 0 S
1111 Rule Winn 1960 only - Sep lastSun 2:00 0 S
1112 Rule Winn 1963 only - Apr lastSun 2:00 1:00 D
1113 Rule Winn 1963 only - Sep 22 2:00 0 S
1114 Rule Winn 1966 1986 - Apr lastSun 2:00 1:00 D
1115 Rule Winn 1966 1986 - Oct lastSun 2:00 0 S
1116 Rule Winn 1987 max - Apr Sun>=1 2:00 1:00 D
1117 # From Paul Eggert (2000-10-02):
1118 # INMS (2000-09-12) says that, since 1988 at least, Manitoba switches from
1119 # DST at 03:00 local time. For now, assume it started in 1987.
1120 Rule Winn 1987 max - Oct lastSun 2:00s 0 S
1121 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1122 Zone America/Winnipeg -6:28:36 - LMT 1887 Jul 16
1128 # From Mark Brader (2003-07-26):
1129 # The first actual adoption of DST in Canada was at the municipal
1130 # level. As the [Toronto] Star put it (1912-06-07), "While people
1131 # elsewhere have long been talking of legislation to save daylight,
1132 # the city of Moose Jaw [Saskatchewan] has acted on its own hook."
1133 # DST in Moose Jaw began on Saturday, 1912-06-01 (no time mentioned:
1134 # presumably late evening, as below), and would run until "the end of
1135 # the summer". The discrepancy between municipal time and railroad
1138 # From Paul Eggert (2003-07-27):
1139 # Willett (1914-03) notes that DST "has been in operation ... in the
1140 # City of Moose Jaw, Saskatchewan, for one year."
1142 # From Paul Eggert (2000-10-02):
1143 # Shanks writes that since 1970 most of this region has been like Regina.
1144 # Some western towns (e.g. Swift Current) switched from MST/MDT to CST in 1972.
1145 # Other western towns (e.g. Lloydminster) are like Edmonton.
1146 # Matthews and Vincent (1998) write that Denare Beach and Creighton
1147 # are like Winnipeg, in violation of Saskatchewan law.
1149 # From W. Jones <jones@skdad.usask.ca> (1992-11-06):
1150 # The. . .below is based on information I got from our law library, the
1151 # provincial archives, and the provincial Community Services department.
1152 # A precise history would require digging through newspaper archives, and
1153 # since you didn't say what you wanted, I didn't bother.
1155 # Saskatchewan is split by a time zone meridian (105W) and over the years
1156 # the boundary became pretty ragged as communities near it reevaluated
1157 # their affiliations in one direction or the other. In 1965 a provincial
1158 # referendum favoured legislating common time practices.
1160 # On 15 April 1966 the Time Act (c. T-14, Revised Statutes of
1161 # Saskatchewan 1978) was proclaimed, and established that the eastern
1162 # part of Saskatchewan would use CST year round, that districts in
1163 # northwest Saskatchewan would by default follow CST but could opt to
1164 # follow Mountain Time rules (thus 1 hour difference in the winter and
1165 # zero in the summer), and that districts in southwest Saskatchewan would
1166 # by default follow MT but could opt to follow CST.
1168 # It took a few years for the dust to settle (I know one story of a town
1169 # on one time zone having its school in another, such that a mom had to
1170 # serve her family lunch in two shifts), but presently it seems that only
1171 # a few towns on the border with Alberta (e.g. Lloydminster) follow MT
1172 # rules any more; all other districts appear to have used CST year round
1173 # since sometime in the 1960s.
1175 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
1176 Rule Regina 1918 only - Apr 14 2:00 1:00 D
1177 Rule Regina 1918 only - Oct 31 2:00 0 S
1178 Rule Regina 1930 1934 - May Sun>=1 0:00 1:00 D
1179 Rule Regina 1930 1934 - Oct Sun>=1 0:00 0 S
1180 Rule Regina 1937 1941 - Apr Sun>=8 0:00 1:00 D
1181 Rule Regina 1937 only - Oct Sun>=8 0:00 0 S
1182 Rule Regina 1938 only - Oct Sun>=1 0:00 0 S
1183 Rule Regina 1939 1941 - Oct Sun>=8 0:00 0 S
1184 Rule Regina 1942 only - Feb 9 2:00 1:00 W # War
1185 Rule Regina 1945 only - Aug 14 23:00u 1:00 P # Peace
1186 Rule Regina 1945 only - Sep lastSun 2:00 0 S
1187 Rule Regina 1946 only - Apr Sun>=8 2:00 1:00 D
1188 Rule Regina 1946 only - Oct Sun>=8 2:00 0 S
1189 Rule Regina 1947 1957 - Apr lastSun 2:00 1:00 D
1190 Rule Regina 1947 1957 - Sep lastSun 2:00 0 S
1191 Rule Regina 1959 only - Apr lastSun 2:00 1:00 D
1192 Rule Regina 1959 only - Oct lastSun 2:00 0 S
1194 Rule Swift 1957 only - Apr lastSun 2:00 1:00 D
1195 Rule Swift 1957 only - Oct lastSun 2:00 0 S
1196 Rule Swift 1959 1961 - Apr lastSun 2:00 1:00 D
1197 Rule Swift 1959 only - Oct lastSun 2:00 0 S
1198 Rule Swift 1960 1961 - Sep lastSun 2:00 0 S
1199 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1200 Zone America/Regina -6:58:36 - LMT 1905 Sep
1201 -7:00 Regina M%sT 1960 Apr lastSun 2:00
1203 Zone America/Swift_Current -7:11:20 - LMT 1905 Sep
1204 -7:00 Canada M%sT 1946 Apr lastSun 2:00
1205 -7:00 Regina M%sT 1950
1206 -7:00 Swift M%sT 1972 Apr lastSun 2:00
1212 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
1213 Rule Edm 1918 1919 - Apr Sun>=8 2:00 1:00 D
1214 Rule Edm 1918 only - Oct 31 2:00 0 S
1215 Rule Edm 1919 only - May 27 2:00 0 S
1216 Rule Edm 1920 1923 - Apr lastSun 2:00 1:00 D
1217 Rule Edm 1920 only - Oct lastSun 2:00 0 S
1218 Rule Edm 1921 1923 - Sep lastSun 2:00 0 S
1219 Rule Edm 1942 only - Feb 9 2:00 1:00 W # War
1220 Rule Edm 1945 only - Aug 14 23:00u 1:00 P # Peace
1221 Rule Edm 1945 only - Sep lastSun 2:00 0 S
1222 Rule Edm 1947 only - Apr lastSun 2:00 1:00 D
1223 Rule Edm 1947 only - Sep lastSun 2:00 0 S
1224 Rule Edm 1967 only - Apr lastSun 2:00 1:00 D
1225 Rule Edm 1967 only - Oct lastSun 2:00 0 S
1226 Rule Edm 1969 only - Apr lastSun 2:00 1:00 D
1227 Rule Edm 1969 only - Oct lastSun 2:00 0 S
1228 Rule Edm 1972 1986 - Apr lastSun 2:00 1:00 D
1229 Rule Edm 1972 max - Oct lastSun 2:00 0 S
1230 Rule Edm 1987 max - Apr Sun>=1 2:00 1:00 D
1231 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1232 Zone America/Edmonton -7:33:52 - LMT 1906 Sep
1238 # From Paul Eggert (2000-10-02):
1239 # Shanks writes that since 1970 most of this region has been like Vancouver.
1240 # Dawson Creek uses MST. Much of east BC is like Edmonton.
1241 # Matthews and Vincent (1998) write that Creston is like Dawson Creek.
1243 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
1244 Rule Vanc 1918 only - Apr 14 2:00 1:00 D
1245 Rule Vanc 1918 only - Oct 31 2:00 0 S
1246 Rule Vanc 1942 only - Feb 9 2:00 1:00 W # War
1247 Rule Vanc 1945 only - Aug 14 23:00u 1:00 P # Peace
1248 Rule Vanc 1945 only - Sep 30 2:00 0 S
1249 Rule Vanc 1946 1986 - Apr lastSun 2:00 1:00 D
1250 Rule Vanc 1946 only - Oct 13 2:00 0 S
1251 Rule Vanc 1947 1961 - Sep lastSun 2:00 0 S
1252 Rule Vanc 1962 max - Oct lastSun 2:00 0 S
1253 Rule Vanc 1987 max - Apr Sun>=1 2:00 1:00 D
1254 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1255 Zone America/Vancouver -8:12:28 - LMT 1884
1257 Zone America/Dawson_Creek -8:00:56 - LMT 1884
1258 -8:00 Canada P%sT 1947
1259 -8:00 Vanc P%sT 1972 Aug 30 2:00
1263 # Northwest Territories, Nunavut, Yukon
1265 # From Paul Eggert (1999-10-29):
1266 # Dawson switched to PST in 1973. Inuvik switched to MST in 1979.
1267 # Mathew Englander <mathew@io.org> (1996-10-07) gives the following refs:
1268 # * 1967. Paragraph 28(34)(g) of the Interpretation Act, S.C. 1967-68,
1269 # c. 7 defines Yukon standard time as UTC-9. This is still valid;
1270 # see Interpretation Act, R.S.C. 1985, c. I-21, s. 35(1).
1271 # * C.O. 1973/214 switched Yukon to PST on 1973-10-28 00:00.
1272 # * O.I.C. 1980/02 established DST.
1273 # * O.I.C. 1987/056 changed DST to Apr firstSun 2:00 to Oct lastSun 2:00.
1274 # Shanks says Yukon's 1973-10-28 switch was at 2:00; go with Englander.
1276 # From Rives McDow (1999-09-04):
1277 # Nunavut ... moved ... to incorporate the whole territory into one time zone.
1278 # <a href="http://www.nunatsiaq.com/nunavut/nvt90903_13.html">
1279 # Nunavut moves to single time zone Oct. 31
1282 # From Antoine Leca (1999-09-06):
1283 # We then need to create a new timezone for the Kitikmeot region of Nunavut
1284 # to differentiate it from the Yellowknife region.
1286 # From Paul Eggert (1999-09-20):
1287 # <a href="http://www.nunavut.com/basicfacts/english/basicfacts_1territory.html">
1288 # Basic Facts: The New Territory
1289 # </a> (1999) reports that Pangnirtung operates on eastern time,
1290 # and that Coral Harbour does not observe DST. We don't know when
1291 # Pangnirtung switched to eastern time; we'll guess 1995.
1292 # We'll ignore the claim about Coral Harbour for now,
1293 # since we have no further info.
1295 # From Rives McDow (1999-11-08):
1296 # On October 31, when the rest of Nunavut went to Central time,
1297 # Pangnirtung wobbled. Here is the result of their wobble:
1299 # The following businesses and organizations in Pangnirtung use Central Time:
1301 # First Air, Power Corp, Nunavut Construction, Health Center, RCMP,
1302 # Eastern Arctic National Parks, A & D Specialist
1304 # The following businesses and organizations in Pangnirtung use Eastern Time:
1306 # Hamlet office, All other businesses, Both schools, Airport operator
1308 # This has made for an interesting situation there, which warranted the news.
1309 # No one there that I spoke with seems concerned, or has plans to
1310 # change the local methods of keeping time, as it evidently does not
1311 # really interfere with any activities or make things difficult locally.
1312 # They plan to celebrate New Year's turn-over twice, one hour apart,
1313 # so it appears that the situation will last at least that long.
1314 # The Nunavut Intergovernmental Affairs hopes that they will "come to
1315 # their senses", but the locals evidently don't see any problem with
1316 # the current state of affairs.
1318 # From Michaela Rodrigue, writing in the
1319 # <a href="http://www.nunatsiaq.com/archives/nunavut991130/nvt91119_17.html">
1320 # Nunatsiaq News (1999-11-19)</a>:
1321 # Clyde River, Pangnirtung and Sanikiluaq now operate with two time zones,
1322 # central - or Nunavut time - for government offices, and eastern time
1323 # for municipal offices and schools.... Igloolik [was similar but then]
1324 # made the switch to central time on Saturday, Nov. 6.
1326 # From Paul Eggert (2000-10-02):
1327 # Matthews and Vincent (1998) say the following, but we lack histories
1328 # for these potential new Zones.
1330 # The Canadian Forces station at Alert uses Eastern Time while the
1331 # handful of residents at the Eureka weather station [in the Central
1332 # zone] skip daylight savings. Baffin Island, which is crossed by the
1333 # Central, Eastern and Atlantic Time zones only uses Eastern Time.
1334 # Gjoa Haven, Taloyoak and Pelly Bay all use Mountain instead of
1335 # Central Time and Southampton Island [in the Central zone] is not
1336 # required to use daylight savings.
1339 # <a href="http://www.nunatsiaq.com/archives/nunavut001130/nvt21110_02.html">
1340 # Nunavut now has two time zones
1341 # </a> (2000-11-10):
1342 # The Nunavut government would allow its employees in Kugluktuk and
1343 # Cambridge Bay to operate on central time year-round, putting them
1344 # one hour behind the rest of Nunavut for six months during the winter.
1345 # At the end of October the two communities had rebelled against
1346 # Nunavut's unified time zone, refusing to shift to eastern time with
1347 # the rest of the territory for the winter. Cambridge Bay remained on
1348 # central time, while Kugluktuk, even farther west, reverted to
1349 # mountain time, which they had used before the advent of Nunavut's
1350 # unified time zone in 1999.
1352 # From Rives McDow (2001-01-20), quoting the Nunavut government:
1353 # The preceding decision came into effect at midnight, Saturday Nov 4, 2000.
1355 # From Paul Eggert (2000-12-04):
1356 # Let's just keep track of the official times for now.
1358 # From Rives McDow (2001-03-07):
1359 # The premier of Nunavut has issued a ministerial statement advising
1360 # that effective 2001-04-01, the territory of Nunavut will revert
1361 # back to three time zones (mountain, central, and eastern). Of the
1362 # cities in Nunavut, Coral Harbor is the only one that I know of that
1363 # has said it will not observe dst, staying on EST year round. I'm
1364 # checking for more info, and will get back to you if I come up with
1366 # [Also see <http://www.nunatsiaq.com/nunavut/nvt10309_06.html> (2001-03-09).]
1368 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
1369 Rule NT_YK 1918 only - Apr 14 2:00 1:00 D
1370 Rule NT_YK 1918 only - Oct 27 2:00 0 S
1371 Rule NT_YK 1919 only - May 25 2:00 1:00 D
1372 Rule NT_YK 1919 only - Nov 1 0:00 0 S
1373 Rule NT_YK 1942 only - Feb 9 2:00 1:00 W # War
1374 Rule NT_YK 1945 only - Aug 14 23:00u 1:00 P # Peace
1375 Rule NT_YK 1945 only - Sep 30 2:00 0 S
1376 Rule NT_YK 1965 only - Apr lastSun 0:00 2:00 DD
1377 Rule NT_YK 1965 only - Oct lastSun 2:00 0 S
1378 Rule NT_YK 1980 1986 - Apr lastSun 2:00 1:00 D
1379 Rule NT_YK 1980 max - Oct lastSun 2:00 0 S
1380 Rule NT_YK 1987 max - Apr Sun>=1 2:00 1:00 D
1381 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1382 Zone America/Pangnirtung -4:22:56 - LMT 1884
1383 -4:00 NT_YK A%sT 1995 Apr Sun>=1 2:00
1384 -5:00 Canada E%sT 1999 Oct 31 2:00
1385 -6:00 Canada C%sT 2000 Oct 29 2:00
1387 Zone America/Iqaluit -4:33:52 - LMT 1884 # Frobisher Bay before 1987
1388 -5:00 NT_YK E%sT 1999 Oct 31 2:00
1389 -6:00 Canada C%sT 2000 Oct 29 2:00
1391 Zone America/Rankin_Inlet -6:08:40 - LMT 1884
1392 -6:00 NT_YK C%sT 2000 Oct 29 2:00
1393 -5:00 - EST 2001 Apr 1 3:00
1395 Zone America/Cambridge_Bay -7:00:20 - LMT 1884
1396 -7:00 NT_YK M%sT 1999 Oct 31 2:00
1397 -6:00 Canada C%sT 2000 Oct 29 2:00
1398 -5:00 - EST 2000 Nov 5 0:00
1399 -6:00 - CST 2001 Apr 1 3:00
1401 Zone America/Yellowknife -7:37:24 - LMT 1884
1403 Zone America/Inuvik -8:54:00 - LMT 1884
1404 -8:00 NT_YK P%sT 1979 Apr lastSun 2:00
1406 Zone America/Whitehorse -9:00:12 - LMT 1900 Aug 20
1407 -9:00 NT_YK Y%sT 1966 Jul 1 2:00
1409 Zone America/Dawson -9:17:40 - LMT 1900 Aug 20
1410 -9:00 NT_YK Y%sT 1973 Oct 28 0:00
1414 ###############################################################################
1418 # From Paul Eggert (2001-03-05):
1419 # The Investigation and Analysis Service of the
1420 # Mexican Library of Congress (MLoC) has published a
1421 # <a href="http://www.cddhcu.gob.mx/bibliot/publica/inveyana/polisoc/horver/">
1422 # history of Mexican local time (in Spanish)
1425 # Here are the discrepancies between Shanks and the MLoC.
1426 # (In all cases we go with the MLoC.)
1427 # Shanks reports that Baja was at -8:00 in 1922/1923.
1428 # Shanks says the 1930 transition in Baja was 1930-11-16.
1429 # Shanks reports no DST during summer 1931.
1430 # Shanks reports a transition at 1032-03-30 23:00, not 1932-04-01.
1431 # Shanks does not report transitions for Baja in 1945 or 1948.
1432 # Shanks reports southern Mexico transitions on 1981-12-01, not 12-23.
1433 # Shanks says Quintana Roo switched to -6:00 on 1982-12-02, and to -5:00
1434 # on 1997-10-26 at 02:00.
1436 # From Gwillim Law (2001-02-20):
1437 # There are some other discrepancies between the Decrees page and the
1438 # tz database. I think they can best be explained by supposing that
1439 # the researchers who prepared the Decrees page failed to find some of
1440 # the relevant documents.
1442 # From Paul Eggert (2000-07-26):
1443 # Shanks gives 1942-04-01 instead of 1942-04-24, and omits the 1981
1444 # and 1988 DST experiments. Go with spin.com.mx.
1446 # From Alan Perry <alan.perry@eng.sun.com> (1996-02-15):
1447 # A guy from our Mexico subsidiary finally found the Presidential Decree
1448 # outlining the timezone changes in Mexico.
1450 # ------------- Begin Forwarded Message -------------
1452 # I finally got my hands on the Official Presidential Decree that sets up the
1453 # rules for the DST changes. The rules are:
1455 # 1. The country is divided in 3 timezones:
1456 # - Baja California Norte (the Mexico/BajaNorte TZ)
1457 # - Baja California Sur, Nayarit, Sinaloa and Sonora (the Mexico/BajaSur TZ)
1458 # - The rest of the country (the Mexico/General TZ)
1460 # 2. From the first Sunday in April at 2:00 AM to the last Sunday in October
1461 # at 2:00 AM, the times in each zone are as follows:
1466 # 3. The rest of the year, the times are as follows:
1471 # The Decree was published in Mexico's Official Newspaper on January 4th.
1473 # -------------- End Forwarded Message --------------
1474 # From Paul Eggert (1996-06-12):
1475 # For an English translation of the decree, see
1476 # <a href="http://mexico-travel.com/extra/timezone_eng.html">
1477 # ``Diario Oficial: Time Zone Changeover'' (1996-01-04).
1480 # From Rives McDow (1998-10-08):
1481 # The State of Quintana Roo has reverted back to central STD and DST times
1482 # (i.e. UTC -0600 and -0500 as of 1998-08-02).
1484 # From Rives McDow (2000-01-10):
1485 # Effective April 4, 1999 at 2:00 AM local time, Sonora changed to the time
1486 # zone 5 hours from the International Date Line, and will not observe daylight
1487 # savings time so as to stay on the same time zone as the southern part of
1488 # Arizona year round.
1490 # From Jesper Norgaard, translating
1491 # <http://www.reforma.com/nacional/articulo/064327/> (2001-01-17):
1492 # In Oaxaca, the 55.000 teachers from the Section 22 of the National
1493 # Syndicate of Education Workers, refuse to apply daylight saving each
1494 # year, so that the more than 10,000 schools work at normal hour the
1497 # From Gwillim Law (2001-01-19):
1498 # <http://www.reforma.com/negocios_y_dinero/articulo/064481/> ... says
1500 # January 17, 2000 - The Energy Secretary, Ernesto Martens, announced
1501 # that Summer Time will be reduced from seven to five months, starting
1503 # <http://www.publico.com.mx/scripts/texto3.asp?action=pagina&pag=21&pos=p&secc=naci&date=01/17/2001>
1504 # [translated], says "summer time will ... take effect on the first Sunday
1505 # in May, and end on the last Sunday of September.
1507 # From Arthur David Olson (2001-01-25):
1508 # The 2001-01-24 traditional Washington Post contained the page one
1509 # story "Timely Issue Divides Mexicans."...
1510 # http://www.washingtonpost.com/wp-dyn/articles/A37383-2001Jan23.html
1511 # ... Mexico City Mayor Lopez Obrador "...is threatening to keep
1512 # Mexico City and its 20 million residents on a different time than
1513 # the rest of the country..." In particular, Lopez Obrador would abolish
1514 # observation of Daylight Saving Time.
1516 # <a href="http://www.conae.gob.mx/ahorro/decretohorver2001.html#decre">
1517 # Official statute published by the Energy Department
1518 # </a> (2001-02-01) shows Baja and Chihauhua as still using US DST rules,
1519 # and Sonora with no DST. This was reported by Jesper Norgaard (2001-02-03).
1521 # From Paul Eggert (2001-03-03):
1523 # <a href="http://www.latimes.com/news/nation/20010303/t000018766.html">
1524 # James F. Smith writes in today's LA Times
1526 # * Sonora will continue to observe standard time.
1527 # * Last week Mexico City's mayor Andres Manuel Lopez Obrador decreed that
1528 # the Federal District will not adopt DST.
1529 # * 4 of 16 district leaders announced they'll ignore the decree.
1530 # * The decree does not affect federal-controlled facilities including
1531 # the airport, banks, hospitals, and schools.
1533 # For now we'll assume that the Federal District will bow to federal rules.
1535 # From Jesper Norgaard (2001-04-01):
1536 # I found some references to the Mexican application of daylight
1537 # saving, which modifies what I had already sent you, stating earlier
1538 # that a number of northern Mexican states would go on daylight
1539 # saving. The modification reverts this to only cover Baja California
1540 # (Norte), while all other states (except Sonora, who has no daylight
1541 # saving all year) will follow the original decree of president
1542 # Vicente Fox, starting daylight saving May 6, 2001 and ending
1543 # September 30, 2001.
1544 # References: "Diario de Monterrey" <www.diariodemonterrey.com/index.asp>
1545 # Palabra <http://palabra.infosel.com/010331/primera/ppri3101.pdf> (2001-03-31)
1547 # From Reuters (2001-09-04):
1548 # Mexico's Supreme Court on Tuesday declared that daylight savings was
1549 # unconstitutional in Mexico City, creating the possibility the
1550 # capital will be in a different time zone from the rest of the nation
1551 # next year.... The Supreme Court's ruling takes effect at 2:00
1552 # a.m. (0800 GMT) on Sept. 30, when Mexico is scheduled to revert to
1553 # standard time. "This is so residents of the Federal District are not
1554 # subject to unexpected time changes," a statement from the court said.
1556 # From Jesper Norgaard Welen (2002-03-12):
1557 # ... consulting my local grocery store(!) and my coworkers, they all insisted
1558 # that a new decision had been made to reinstate US style DST in Mexico....
1559 # http://www.conae.gob.mx/ahorro/horaver2001_m1_2002.html (2002-02-20)
1560 # confirms this. Sonora as usual is the only state where DST is not applied.
1562 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
1563 Rule Mexico 1939 only - Feb 5 0:00 1:00 D
1564 Rule Mexico 1939 only - Jun 25 0:00 0 S
1565 Rule Mexico 1940 only - Dec 9 0:00 1:00 D
1566 Rule Mexico 1941 only - Apr 1 0:00 0 S
1567 Rule Mexico 1943 only - Dec 16 0:00 1:00 W # War
1568 Rule Mexico 1944 only - May 1 0:00 0 S
1569 Rule Mexico 1950 only - Feb 12 0:00 1:00 D
1570 Rule Mexico 1950 only - Jul 30 0:00 0 S
1571 Rule Mexico 1996 2000 - Apr Sun>=1 2:00 1:00 D
1572 Rule Mexico 1996 2000 - Oct lastSun 2:00 0 S
1573 Rule Mexico 2001 only - May Sun>=1 2:00 1:00 D
1574 Rule Mexico 2001 only - Sep lastSun 2:00 0 S
1575 Rule Mexico 2002 max - Apr Sun>=1 2:00 1:00 D
1576 Rule Mexico 2002 max - Oct lastSun 2:00 0 S
1577 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1579 Zone America/Cancun -5:47:04 - LMT 1922 Jan 1 0:12:56
1580 -6:00 - CST 1981 Dec 23
1581 -5:00 Mexico E%sT 1998 Aug 2 2:00
1584 Zone America/Merida -5:58:28 - LMT 1922 Jan 1 0:01:32
1585 -6:00 - CST 1981 Dec 23
1586 -5:00 - EST 1982 Dec 2
1588 # Coahuila, Durango, Nuevo Leon, Tamaulipas
1589 Zone America/Monterrey -6:41:16 - LMT 1921 Dec 31 23:18:44
1594 Zone America/Mexico_City -6:36:36 - LMT 1922 Jan 1 0:23:24
1595 -7:00 - MST 1927 Jun 10 23:00
1596 -6:00 - CST 1930 Nov 15
1597 -7:00 - MST 1931 May 1 23:00
1598 -6:00 - CST 1931 Oct
1599 -7:00 - MST 1932 Apr 1
1600 -6:00 Mexico C%sT 2001 Sep 30 02:00
1601 -6:00 - CST 2002 Feb 20
1604 Zone America/Chihuahua -7:04:20 - LMT 1921 Dec 31 23:55:40
1605 -7:00 - MST 1927 Jun 10 23:00
1606 -6:00 - CST 1930 Nov 15
1607 -7:00 - MST 1931 May 1 23:00
1608 -6:00 - CST 1931 Oct
1609 -7:00 - MST 1932 Apr 1
1611 -6:00 Mexico C%sT 1998
1612 -6:00 - CST 1998 Apr Sun>=1 3:00
1615 Zone America/Hermosillo -7:23:52 - LMT 1921 Dec 31 23:36:08
1616 -7:00 - MST 1927 Jun 10 23:00
1617 -6:00 - CST 1930 Nov 15
1618 -7:00 - MST 1931 May 1 23:00
1619 -6:00 - CST 1931 Oct
1620 -7:00 - MST 1932 Apr 1
1621 -6:00 - CST 1942 Apr 24
1622 -7:00 - MST 1949 Jan 14
1624 -7:00 Mexico M%sT 1999
1626 # Baja California Sur, Nayarit, Sinaloa
1627 Zone America/Mazatlan -7:05:40 - LMT 1921 Dec 31 23:54:20
1628 -7:00 - MST 1927 Jun 10 23:00
1629 -6:00 - CST 1930 Nov 15
1630 -7:00 - MST 1931 May 1 23:00
1631 -6:00 - CST 1931 Oct
1632 -7:00 - MST 1932 Apr 1
1633 -6:00 - CST 1942 Apr 24
1634 -7:00 - MST 1949 Jan 14
1638 Zone America/Tijuana -7:48:04 - LMT 1922 Jan 1 0:11:56
1640 -8:00 - PST 1927 Jun 10 23:00
1641 -7:00 - MST 1930 Nov 15
1642 -8:00 - PST 1931 Apr 1
1643 -8:00 1:00 PDT 1931 Sep 30
1644 -8:00 - PST 1942 Apr 24
1645 -8:00 1:00 PWT 1945 Nov 12
1646 -8:00 - PST 1948 Apr 5
1647 -8:00 1:00 PDT 1949 Jan 14
1652 -8:00 Mexico P%sT 2001
1653 -8:00 US P%sT 2002 Feb 20
1655 # From Paul Eggert (2001-03-05):
1656 # Formerly there was an America/Ensenada zone, which differed from
1657 # America/Tijuana only in that it did not observe DST from 1976
1658 # through 1995. This was as per Shanks. However, Guy Harris reports
1659 # that the 1987 OAG says "Only Ensenada, Mexicale, San Felipe and
1660 # Tijuana observe DST," which contradicts Shanks but does imply that
1661 # DST-observance was a town-by-town matter back then. This concerns
1662 # data after 1970 so most likely there should be at least one Zone
1663 # other than America/Tijuana for Baja, but it's not clear yet what its
1664 # name or contents should be.
1669 ###############################################################################
1672 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1673 Zone America/Anguilla -4:12:16 - LMT 1912 Mar 2
1676 # Antigua and Barbuda
1677 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1678 Zone America/Antigua -4:07:12 - LMT 1912 Mar 2
1683 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
1684 Rule Bahamas 1964 max - Oct lastSun 2:00 0 S
1685 Rule Bahamas 1964 1986 - Apr lastSun 2:00 1:00 D
1686 Rule Bahamas 1987 max - Apr Sun>=1 2:00 1:00 D
1687 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1688 Zone America/Nassau -5:09:24 - LMT 1912 Mar 2
1692 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
1693 Rule Barb 1977 only - Jun 12 2:00 1:00 D
1694 Rule Barb 1977 1978 - Oct Sun>=1 2:00 0 S
1695 Rule Barb 1978 1980 - Apr Sun>=15 2:00 1:00 D
1696 Rule Barb 1979 only - Sep 30 2:00 0 S
1697 Rule Barb 1980 only - Sep 25 2:00 0 S
1698 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1699 Zone America/Barbados -3:58:28 - LMT 1924 # Bridgetown
1700 -3:58:28 - BMT 1932 # Bridgetown Mean Time
1704 # Whitman entirely disagrees with Shanks; go with Shanks.
1705 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
1706 Rule Belize 1918 1942 - Oct Sun>=2 0:00 0:30 HD
1707 Rule Belize 1919 1943 - Feb Sun>=9 0:00 0 S
1708 Rule Belize 1973 only - Dec 5 0:00 1:00 D
1709 Rule Belize 1974 only - Feb 9 0:00 0 S
1710 Rule Belize 1982 only - Dec 18 0:00 1:00 D
1711 Rule Belize 1983 only - Feb 12 0:00 0 S
1712 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1713 Zone America/Belize -5:52:48 - LMT 1912 Apr
1717 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1718 Zone Atlantic/Bermuda -4:19:04 - LMT 1930 Jan 1 2:00 # Hamilton
1719 -4:00 - AST 1974 Apr 28 2:00
1723 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1724 Zone America/Cayman -5:25:32 - LMT 1890 # Georgetown
1725 -5:07:12 - KMT 1912 Feb # Kingston Mean Time
1729 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
1730 Rule CR 1979 1980 - Feb lastSun 0:00 1:00 D
1731 Rule CR 1979 1980 - Jun Sun>=1 0:00 0 S
1732 Rule CR 1991 1992 - Jan Sat>=15 0:00 1:00 D
1733 # IATA SSIM (1991-09) says the following was at 1:00; go with Shanks.
1734 Rule CR 1991 only - Jul 1 0:00 0 S
1735 Rule CR 1992 only - Mar 15 0:00 0 S
1736 # There are too many San Joses elsewhere, so we'll use `Costa Rica'.
1737 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1738 Zone America/Costa_Rica -5:36:20 - LMT 1890 # San Jose
1739 -5:36:20 - SJMT 1921 Jan 15 # San Jose Mean Time
1742 # no information; probably like America/Costa_Rica
1746 # From Arthur David Olson (1999-03-29):
1747 # The 1999-03-28 exhibition baseball game held in Havana, Cuba, between
1748 # the Cuban National Team and the Baltimore Orioles was carried live on
1749 # the Orioles Radio Network, including affiliate WTOP in Washington, DC.
1750 # During the game, play-by-play announcer Jim Hunter noted that
1751 # "We'll be losing two hours of sleep...Cuba switched to Daylight Saving
1752 # Time today." (The "two hour" remark referred to losing one hour of
1753 # sleep on 1999-03-28--when the announcers were in Cuba as it switched
1754 # to DST--and one more hour on 1999-04-04--when the announcers will have
1755 # returned to Baltimore, which switches on that date.)
1757 # From Evert van der Veer via Steffen Thorsen (2004-10-28):
1758 # Cuba is not going back to standard time this year.
1759 # From Paul Eggert (2004-10-28):
1760 # http://www.granma.cu/ingles/2004/septiembre/juev30/41medid-i.html
1761 # says that it's due to a problem at the Antonio Guiteras
1762 # thermoelectric plant, and says "This October there will be no return
1763 # to normal hours (after daylight saving time)".
1764 # For now, let's assume that it's a one-year temporary measure.
1766 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
1767 Rule Cuba 1928 only - Jun 10 0:00 1:00 D
1768 Rule Cuba 1928 only - Oct 10 0:00 0 S
1769 Rule Cuba 1940 1942 - Jun Sun>=1 0:00 1:00 D
1770 Rule Cuba 1940 1942 - Sep Sun>=1 0:00 0 S
1771 Rule Cuba 1945 1946 - Jun Sun>=1 0:00 1:00 D
1772 Rule Cuba 1945 1946 - Sep Sun>=1 0:00 0 S
1773 Rule Cuba 1965 only - Jun 1 0:00 1:00 D
1774 Rule Cuba 1965 only - Sep 30 0:00 0 S
1775 Rule Cuba 1966 only - May 29 0:00 1:00 D
1776 Rule Cuba 1966 only - Oct 2 0:00 0 S
1777 Rule Cuba 1967 only - Apr 8 0:00 1:00 D
1778 Rule Cuba 1967 1968 - Sep Sun>=8 0:00 0 S
1779 Rule Cuba 1968 only - Apr 14 0:00 1:00 D
1780 Rule Cuba 1969 1977 - Apr lastSun 0:00 1:00 D
1781 Rule Cuba 1969 1971 - Oct lastSun 0:00 0 S
1782 Rule Cuba 1972 1974 - Oct 8 0:00 0 S
1783 Rule Cuba 1975 1977 - Oct lastSun 0:00 0 S
1784 Rule Cuba 1978 only - May 7 0:00 1:00 D
1785 Rule Cuba 1978 1990 - Oct Sun>=8 0:00 0 S
1786 Rule Cuba 1979 1980 - Mar Sun>=15 0:00 1:00 D
1787 Rule Cuba 1981 1985 - May Sun>=5 0:00 1:00 D
1788 Rule Cuba 1986 1989 - Mar Sun>=14 0:00 1:00 D
1789 Rule Cuba 1990 1997 - Apr Sun>=1 0:00 1:00 D
1790 Rule Cuba 1991 1995 - Oct Sun>=8 0:00s 0 S
1791 Rule Cuba 1996 only - Oct 6 0:00s 0 S
1792 Rule Cuba 1997 only - Oct 12 0:00s 0 S
1793 Rule Cuba 1998 1999 - Mar lastSun 0:00s 1:00 D
1794 Rule Cuba 1998 2003 - Oct lastSun 0:00s 0 S
1795 Rule Cuba 2000 max - Apr Sun>=1 0:00s 1:00 D
1796 Rule Cuba 2005 max - Oct lastSun 0:00s 0 S
1798 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1799 Zone America/Havana -5:29:28 - LMT 1890
1800 -5:29:36 - HMT 1925 Jul 19 12:00 # Havana MT
1804 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1805 Zone America/Dominica -4:05:36 - LMT 1911 Jul 1 0:01 # Roseau
1808 # Dominican Republic
1810 # From Steffen Thorsen (2000-10-30):
1811 # Enrique Morales reported to me that the Dominican Republic has changed the
1812 # time zone to Eastern Standard Time as of Sunday 29 at 2 am....
1813 # http://www.listin.com.do/antes/261000/republica/princi.html
1815 # From Paul Eggert (2000-12-04):
1816 # That URL (2000-10-26, in Spanish) says they planned to use US-style DST.
1818 # From Rives McDow (2000-12-01):
1819 # Dominican Republic changed its mind and presidential decree on Tuesday,
1820 # November 28, 2000, with a new decree. On Sunday, December 3 at 1:00 AM the
1821 # Dominican Republic will be reverting to 8 hours from the International Date
1822 # Line, and will not be using DST in the foreseeable future. The reason they
1823 # decided to use DST was to be in synch with Puerto Rico, who was also going
1824 # to implement DST. When Puerto Rico didn't implement DST, the president
1825 # decided to revert.
1828 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
1829 Rule DR 1966 only - Oct 30 0:00 1:00 D
1830 Rule DR 1967 only - Feb 28 0:00 0 S
1831 Rule DR 1969 1973 - Oct lastSun 0:00 0:30 HD
1832 Rule DR 1970 only - Feb 21 0:00 0 S
1833 Rule DR 1971 only - Jan 20 0:00 0 S
1834 Rule DR 1972 1974 - Jan 21 0:00 0 S
1835 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1836 Zone America/Santo_Domingo -4:39:36 - LMT 1890
1837 -4:40 - SDMT 1933 Apr 1 12:00 # S. Dom. MT
1838 -5:00 DR E%sT 1974 Oct 27
1839 -4:00 - AST 2000 Oct 29 02:00
1840 -5:00 US E%sT 2000 Dec 3 01:00
1844 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
1845 Rule Salv 1987 1988 - May Sun>=1 0:00 1:00 D
1846 Rule Salv 1987 1988 - Sep lastSun 0:00 0 S
1847 # There are too many San Salvadors elsewhere, so use America/El_Salvador
1848 # instead of America/San_Salvador.
1849 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1850 Zone America/El_Salvador -5:56:48 - LMT 1921 # San Salvador
1854 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1855 Zone America/Grenada -4:07:00 - LMT 1911 Jul # St George's
1859 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1860 Zone America/Guadeloupe -4:06:08 - LMT 1911 Jun 8 # Pointe a Pitre
1864 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
1865 Rule Guat 1973 only - Nov 25 0:00 1:00 D
1866 Rule Guat 1974 only - Feb 24 0:00 0 S
1867 Rule Guat 1983 only - May 21 0:00 1:00 D
1868 Rule Guat 1983 only - Sep 22 0:00 0 S
1869 Rule Guat 1991 only - Mar 23 0:00 1:00 D
1870 Rule Guat 1991 only - Sep 7 0:00 0 S
1871 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1872 Zone America/Guatemala -6:02:04 - LMT 1918 Oct 5
1876 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
1877 Rule Haiti 1983 only - May 8 0:00 1:00 D
1878 Rule Haiti 1984 1987 - Apr lastSun 0:00 1:00 D
1879 Rule Haiti 1983 1987 - Oct lastSun 0:00 0 S
1880 # Shanks says AT is 2:00, but IATA SSIM (1991/1997) says 1:00s. Go with IATA.
1881 Rule Haiti 1988 1997 - Apr Sun>=1 1:00s 1:00 D
1882 Rule Haiti 1988 1997 - Oct lastSun 1:00s 0 S
1883 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1884 Zone America/Port-au-Prince -4:49:20 - LMT 1890
1885 -4:49 - PPMT 1917 Jan 24 12:00 # P-a-P MT
1889 # Shanks says 1921 Jan 1; go with Whitman's more precise Apr 1.
1890 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1891 Zone America/Tegucigalpa -5:48:52 - LMT 1921 Apr
1894 # Great Swan I ceded by US to Honduras in 1972
1898 # From Bob Devine (1988-01-28):
1901 # From U. S. Naval Observatory (1989-01-19):
1902 # JAMAICA 5 H BEHIND UTC
1905 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1906 Zone America/Jamaica -5:07:12 - LMT 1890 # Kingston
1907 -5:07:12 - KMT 1912 Feb # Kingston Mean Time
1908 -5:00 - EST 1974 Apr 28 2:00
1913 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1914 Zone America/Martinique -4:04:20 - LMT 1890 # Fort-de-France
1915 -4:04:20 - FFMT 1911 May # Fort-de-France MT
1916 -4:00 - AST 1980 Apr 6
1917 -4:00 1:00 ADT 1980 Sep 28
1921 # From Paul Eggert (1997-08-31):
1922 # Recent volcanic eruptions have forced evacuation of Plymouth, the capital.
1923 # Luckily, Olveston, the current de facto capital, has the same longitude.
1924 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1925 Zone America/Montserrat -4:08:52 - LMT 1911 Jul 1 0:01 # Olveston
1930 # From Steffen Thorsen (1998-12-29):
1931 # Nicaragua seems to be back at -6:00 but I have not been able to find when
1932 # they changed from -5:00.
1934 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
1935 Rule Nic 1979 1980 - Mar Sun>=16 0:00 1:00 D
1936 Rule Nic 1979 1980 - Jun Mon>=23 0:00 0 S
1937 Rule Nic 1992 only - Jan 1 4:00 1:00 D
1938 Rule Nic 1992 only - Sep 24 0:00 0 S
1939 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1940 Zone America/Managua -5:45:08 - LMT 1890
1941 -5:45:12 - MMT 1934 Jun 23 # Managua Mean Time?
1942 -6:00 - CST 1973 May
1943 -5:00 - EST 1975 Feb 16
1944 -6:00 Nic C%sT 1993 Jan 1 4:00
1945 -5:00 - EST 1998 Dec
1949 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1950 Zone America/Panama -5:18:08 - LMT 1890
1951 -5:19:36 - CMT 1908 Apr 22 # Colon Mean Time
1955 # There are too many San Juans elsewhere, so we'll use `Puerto_Rico'.
1956 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1957 Zone America/Puerto_Rico -4:24:25 - LMT 1899 Mar 28 12:00 # San Juan
1958 -4:00 - AST 1942 May 3
1959 -4:00 1:00 AWT 1945 Sep 30 2:00
1963 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1964 Zone America/St_Kitts -4:10:52 - LMT 1912 Mar 2 # Basseterre
1968 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1969 Zone America/St_Lucia -4:04:00 - LMT 1890 # Castries
1970 -4:04:00 - CMT 1912 # Castries Mean Time
1973 # St Pierre and Miquelon
1974 # There are too many St Pierres elsewhere, so we'll use `Miquelon'.
1975 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1976 Zone America/Miquelon -3:44:40 - LMT 1911 May 15 # St Pierre
1977 -4:00 - AST 1980 May
1978 -3:00 - PMST 1987 # Pierre & Miquelon Time
1981 # St Vincent and the Grenadines
1982 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1983 Zone America/St_Vincent -4:04:56 - LMT 1890 # Kingstown
1984 -4:04:56 - KMT 1912 # Kingstown Mean Time
1988 # From Paul Eggert (1998-08-06):
1989 # Shanks says they use US DST rules, but IATA SSIM (1991/1998)
1990 # says they switch at midnight. Go with IATA SSIM.
1991 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
1992 Rule TC 1979 1986 - Apr lastSun 0:00 1:00 D
1993 Rule TC 1979 max - Oct lastSun 0:00 0 S
1994 Rule TC 1987 max - Apr Sun>=1 0:00 1:00 D
1995 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1996 Zone America/Grand_Turk -4:44:32 - LMT 1890
1997 -5:07:12 - KMT 1912 Feb # Kingston Mean Time
2001 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
2002 Zone America/Tortola -4:18:28 - LMT 1911 Jul # Road Town
2006 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
2007 Zone America/St_Thomas -4:19:44 - LMT 1911 Jul # Charlotte Amalie