1 # @(#)northamerica 7.43
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, Antique Collectors Club (1997).
12 ###############################################################################
16 # From Paul Eggert <eggert@twinsun.com> (1995-12-19):
17 # A good source for time zone historical data in the US is
18 # Thomas G. Shanks, The American Atlas (5th edition),
19 # San Diego: ACS Publications, Inc. (1991).
20 # Make sure you have the errata sheet; the book is somewhat useless without it.
21 # It is the source for the US and Puerto Rico entries below.
23 # From Paul Eggert (1996-06-12):
24 # Daylight Saving Time was first suggested as a joke by Benjamin Franklin
25 # in his whimsical essay ``Turkey vs Eagle, McCauley is my Beagle'' (1784).
26 # Not everyone is happy with the results:
28 # I don't really care how time is reckoned so long as there is some
29 # agreement about it, but I object to being told that I am saving
30 # daylight when my reason tells me that I am doing nothing of the kind.
31 # I even object to the implication that I am wasting something
32 # valuable if I stay in bed after the sun has risen. As an admirer
33 # of moonlight I resent the bossy insistence of those who want to
34 # reduce my time for enjoying it. At the back of the Daylight Saving
35 # scheme I detect the bony, blue-fingered hand of Puritanism, eager
36 # to push people into bed earlier, and get them up earlier, to make
37 # them healthy, wealthy and wise in spite of themselves.
39 # -- Robertson Davies, The Diary of Samuel Marchbanks (1947), XIX, Sunday
41 # From Arthur David Olson:
42 # US Daylight Saving Time ended on the last Sunday of *October* in 1974.
43 # See, for example, the front page of the Saturday, 1974-10-26
44 # and Sunday, 1974-10-27 editions of the Washington Post.
46 # From Arthur David Olson:
47 # Before the Uniform Time Act of 1966 took effect in 1967, observance of
48 # Daylight Saving Time in the US was by local option, except during wartime.
50 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
51 Rule US 1918 1919 - Mar lastSun 2:00 1:00 W # War
52 Rule US 1918 1919 - Oct lastSun 2:00 0 S
53 Rule US 1942 only - Feb 9 2:00 1:00 W # War
54 Rule US 1945 only - Sep 30 2:00 0 S
55 Rule US 1967 max - Oct lastSun 2:00 0 S
56 Rule US 1967 1973 - Apr lastSun 2:00 1:00 D
57 Rule US 1974 only - Jan 6 2:00 1:00 D
58 Rule US 1975 only - Feb 23 2:00 1:00 D
59 Rule US 1976 1986 - Apr lastSun 2:00 1:00 D
60 Rule US 1987 max - Apr Sun>=1 2:00 1:00 D
61 # <a href="http://thomas.loc.gov/cgi-bin/bdquery/z?d106:h.r.00177:">
63 # </a> (introduced 1999-01-06) would change April to March in the above rule.
65 # From Bob Devine (1988-01-28):
66 # ...Alaska (and Hawaii) had the timezone names changed in 1967.
68 # Pacific Standard Time(PST) -same-
69 # Yukon Standard Time(YST) -same-
70 # Central Alaska S.T. (CAT) Alaska-Hawaii St[an]dard Time (AHST)
71 # Nome Standard Time (NT) Bering Standard Time (BST)
73 # ...Alaska's timezone lines were redrawn in 1983 to give only 2 tz.
74 # The YST zone now covers nearly all of the state, AHST just part
75 # of the Aleutian islands. No DST.
77 # From Paul Eggert (1995-12-19):
78 # The tables below use `NST', not `NT', for Nome Standard Time.
79 # I invented `CAWT' for Central Alaska War Time.
81 # From U. S. Naval Observatory (1989-01-19):
82 # USA EASTERN 5 H BEHIND UTC NEW YORK, WASHINGTON
83 # USA EASTERN 4 H BEHIND UTC APR 3 - OCT 30
84 # USA CENTRAL 6 H BEHIND UTC CHICAGO, HOUSTON
85 # USA CENTRAL 5 H BEHIND UTC APR 3 - OCT 30
86 # USA MOUNTAIN 7 H BEHIND UTC DENVER
87 # USA MOUNTAIN 6 H BEHIND UTC APR 3 - OCT 30
88 # USA PACIFIC 8 H BEHIND UTC L.A., SAN FRANCISCO
89 # USA PACIFIC 7 H BEHIND UTC APR 3 - OCT 30
90 # USA ALASKA STD 9 H BEHIND UTC MOST OF ALASKA (AKST)
91 # USA ALASKA STD 8 H BEHIND UTC APR 3 - OCT 30 (AKDT)
92 # USA ALEUTIAN 10 H BEHIND UTC ISLANDS WEST OF 170W
93 # USA - " - 9 H BEHIND UTC APR 3 - OCT 30
94 # USA HAWAII 10 H BEHIND UTC
95 # USA BERING 11 H BEHIND UTC SAMOA, MIDWAY
97 # From Arthur David Olson (1989-01-21):
98 # The above dates are for 1988.
99 # Note the "AKST" and "AKDT" abbreviations, the claim that there's
100 # no DST in Samoa, and the claim that there is DST in Alaska and the
103 # From Arthur David Olson (1988-02-13):
104 # Legal standard time zone names, from United States Code (1982 Edition and
105 # Supplement III), Title 15, Chapter 6, Section 260 and forward. First, names
106 # up to 1967-04-01 (when most provisions of the Uniform Time Act of 1966
107 # took effect), as explained in sections 263 and 261:
109 # United States standard eastern time
110 # United States standard mountain time
111 # United States standard central time
112 # United States standard Pacific time
114 # United States standard Alaska time
116 # Next, names from 1967-04-01 until 1983-11-30 (the date for
117 # public law 98-181):
118 # Atlantic standard time
119 # eastern standard time
120 # central standard time
121 # mountain standard time
122 # Pacific standard time
123 # Yukon standard time
124 # Alaska-Hawaii standard time
125 # Bering standard time
126 # And after 1983-11-30:
127 # Atlantic standard time
128 # eastern standard time
129 # central standard time
130 # mountain standard time
131 # Pacific standard time
132 # Alaska standard time
133 # Hawaii-Aleutian standard time
134 # Samoa standard time
135 # The law doesn't give abbreviations.
137 # From Paul Eggert (1995-12-19):
138 # Shanks uses 1983-10-30, not 1983-11-30, for the 1983 transitions.
141 # US Eastern time, represented by New York
142 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER
143 Rule NYC 1920 only - Mar lastSun 2:00 1:00 D
144 Rule NYC 1920 only - Oct lastSun 2:00 0 S
145 Rule NYC 1921 1966 - Apr lastSun 2:00 1:00 D
146 Rule NYC 1921 1954 - Sep lastSun 2:00 0 S
147 Rule NYC 1955 1966 - Oct lastSun 2:00 0 S
148 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
149 Zone America/New_York -4:56:02 - LMT 1883 Nov 18 12:00
156 # US Central time, represented by Chicago
157 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER
158 Rule Chicago 1920 only - Jun 13 2:00 1:00 D
159 Rule Chicago 1920 1921 - Oct lastSun 2:00 0 S
160 Rule Chicago 1921 only - Mar lastSun 2:00 1:00 D
161 Rule Chicago 1922 1966 - Apr lastSun 2:00 1:00 D
162 Rule Chicago 1922 1954 - Sep lastSun 2:00 0 S
163 Rule Chicago 1955 1966 - Oct lastSun 2:00 0 S
164 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
165 Zone America/Chicago -5:50:36 - LMT 1883 Nov 18 12:00
167 -6:00 Chicago C%sT 1936 Mar 1 2:00
168 -5:00 - EST 1936 Nov 15 2:00
169 -6:00 Chicago C%sT 1942
171 -6:00 Chicago C%sT 1967
174 # US Mountain time, represented by Denver
175 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER
176 Rule Denver 1920 1921 - Mar lastSun 2:00 1:00 D
177 Rule Denver 1920 only - Oct lastSun 2:00 0 S
178 Rule Denver 1921 only - May 22 2:00 0 S
179 Rule Denver 1965 1966 - Apr lastSun 2:00 1:00 D
180 Rule Denver 1965 1966 - Oct lastSun 2:00 0 S
181 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
182 Zone America/Denver -6:59:56 - LMT 1883 Nov 18 12:00
184 -7:00 Denver M%sT 1942
186 -7:00 Denver M%sT 1967
189 # US Pacific time, represented by Los Angeles
190 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER
191 Rule CA 1948 only - Mar 14 2:00 1:00 D
192 Rule CA 1949 only - Jan 1 2:00 0 S
193 Rule CA 1950 1966 - Apr lastSun 2:00 1:00 D
194 Rule CA 1950 1961 - Sep lastSun 2:00 0 S
195 Rule CA 1962 1966 - Oct lastSun 2:00 0 S
196 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
197 Zone America/Los_Angeles -7:52:58 - LMT 1883 Nov 18 12:00
203 # AK%sT is the modern abbreviation for -9:00 per USNO.
205 # From Paul Eggert (1995-12-19):
206 # Howse writes that Alaska switched from the Julian to the Gregorian calendar,
207 # and from east-of-GMT to west-of-GMT days, when the US bought it from Russia.
208 # This was on 1867-10-18. We omit this transition, since we can't represent
209 # changes from Julian to Gregorian.
211 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
212 Zone America/Juneau -8:57:41 - LMT 1900 Aug 20 12:00
216 -8:00 US P%sT 1983 Oct 30 2:00
218 Zone America/Yakutat -9:18:55 - LMT 1900 Aug 20 12:00
222 -9:00 US Y%sT 1983 Oct 30 2:00
224 Zone America/Anchorage -9:59:36 - LMT 1900 Aug 20 12:00
226 -10:00 US CAT/CAWT 1946
227 -10:00 - CAT 1967 Apr
229 -10:00 US AH%sT 1983 Oct 30 2:00
231 Zone America/Nome -11:01:38 - LMT 1900 Aug 20 12:00
234 -11:00 - NST 1967 Apr
236 -11:00 US B%sT 1983 Oct 30 2:00
238 Zone America/Adak -11:46:38 - LMT 1900 Aug 20 12:00
241 -11:00 - NST 1967 Apr
243 -11:00 US B%sT 1983 Oct 30 2:00
245 # Shanks writes that part of southwest Alaska (e.g. Aniak)
246 # switched from -11:00 to -10:00 on 1968-09-22 at 02:00,
247 # and another part (e.g. Akiak) made the same switch five weeks later.
248 # These switches don't quite make our 1970 cutoff.
252 # From Arthur David Olson:
253 # And then there's Hawaii.
254 # DST was observed for one day in 1933;
255 # standard time was changed by half an hour in 1947;
256 # it's always standard as of 1986.
259 # Shanks says the 1933 experiment lasted for three weeks. Go with Shanks.
261 Zone Pacific/Honolulu -10:31:26 - LMT 1900 Jan 1 12:00
262 -10:30 - HST 1933 Apr 30 2:00
263 -10:30 1:00 HDT 1933 May 21 2:00
264 -10:30 US H%sT 1947 Jun 8 2:00
267 # Now we turn to US areas that have diverged from the consensus since 1970.
269 # Arizona mostly uses MST.
270 Zone America/Phoenix -7:28:18 - LMT 1883 Nov 18 12:00
271 -7:00 US M%sT 1944 Jan 1 00:01
272 -7:00 - MST 1944 Mar 17 00:01
273 -7:00 US M%sT 1944 Oct 1 00:01
277 # From Arthur David Olson (1988-02-13):
278 # A writer from the Inter Tribal Council of Arizona, Inc.,
279 # notes in private correspondence dated 12/28/87 that "Presently, only the
280 # Navajo Nation participates in the Daylight Saving Time policy, due to its
281 # large size and location in three states." (The "only" means that other
282 # tribal nations don't use DST.)
284 Link America/Denver America/Shiprock
286 # Southern Idaho and eastern Oregon switched four weeks late in 1974.
287 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
288 Zone America/Boise -7:44:49 - LMT 1883 Nov 18 12:00
289 -8:00 US P%sT 1923 May 13 2:00
291 -7:00 - MST 1974 Feb 3 2:00
296 # From Paul Eggert (1995-12-19):
297 # Indiana generally observes either EST all year, or CST/CDT,
298 # but areas near Cincinnati and Louisville use those cities' timekeeping
299 # and in 1969 and 1970 the whole state observed daylight time;
300 # and there are other exceptions as noted below.
301 # Shanks partitions Indiana into 345 regions, each with its own time history,
302 # and writes ``Even newspaper reports present contradictory information.''
303 # Fortunately, most of the complexity occurred before our cutoff date of 1970.
305 # Since 1970, EST-only Indiana has been like America/Indianapolis,
306 # with exceptions noted below for Crawford, Starke, and Switzerland counties.
307 # The parts of Indiana not listed below have been like America/Chicago,
308 # America/Louisville, or America/New_York.
310 # Other than Indianapolis, the Indiana place names are so nondescript
311 # that they would be ambiguous if we left them at the `America' level.
312 # So we reluctantly put them all in a subdirectory `America/Indiana'.
314 # Most of EST-only Indiana last observed DST in 1970.
315 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER
316 Rule Indianapolis 1941 only - Jun 22 2:00 1:00 D
317 Rule Indianapolis 1941 1954 - Sep lastSun 2:00 0 S
318 Rule Indianapolis 1946 1954 - Apr lastSun 2:00 1:00 D
319 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
320 Zone America/Indianapolis -5:44:38 - LMT 1883 Nov 18 12:00
322 -6:00 Indianapolis C%sT 1942
324 -6:00 Indianapolis C%sT 1955 Apr 24 2:00
325 -5:00 - EST 1957 Sep 29 2:00
326 -6:00 - CST 1958 Apr 27 2:00
330 Link America/Indianapolis America/Indiana/Indianapolis
332 # Part of Crawford County, Indiana, last observed DST in 1975,
333 # and left its clocks alone in 1974.
334 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER
335 Rule Marengo 1951 only - Apr lastSun 2:00 1:00 D
336 Rule Marengo 1951 only - Sep lastSun 2:00 0 S
337 Rule Marengo 1954 1960 - Apr lastSun 2:00 1:00 D
338 Rule Marengo 1954 1960 - Sep lastSun 2:00 0 S
339 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
340 Zone America/Indiana/Marengo -5:45:23 - LMT 1883 Nov 18 12:00
342 -6:00 Marengo C%sT 1961 Apr 30 2:00
344 -5:00 US E%sT 1974 Jan 6 2:00
345 -6:00 1:00 CDT 1974 Oct 27 2:00
349 # Starke County, Indiana
350 # From Arthur David Olson (1991-10-28):
351 # An article on page A3 of the Sunday, 1991-10-27 Washington Post
352 # notes that Starke County switched from Central time to Eastern time as of
354 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER
355 Rule Starke 1947 1961 - Apr lastSun 2:00 1:00 D
356 Rule Starke 1947 1954 - Sep lastSun 2:00 0 S
357 Rule Starke 1955 1956 - Oct lastSun 2:00 0 S
358 Rule Starke 1957 1958 - Sep lastSun 2:00 0 S
359 Rule Starke 1959 1961 - Oct lastSun 2:00 0 S
360 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
361 Zone America/Indiana/Knox -5:46:30 - LMT 1883 Nov 18 12:00
363 -6:00 Starke C%sT 1962 Apr 29 2:00
364 -5:00 - EST 1963 Oct 27 2:00
365 -6:00 US C%sT 1991 Oct 27 2:00
368 # Switzerland County, Indiana, last observed DST in 1972.
369 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
370 Zone America/Indiana/Vevay -5:40:16 - LMT 1883 Nov 18 12:00
371 -6:00 US C%sT 1954 Apr 25 2:00
376 # Part of Kentucky left its clocks alone in 1974.
377 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER
378 Rule Louisville 1921 only - May 1 2:00 1:00 D
379 Rule Louisville 1921 only - Sep 1 2:00 0 S
380 Rule Louisville 1941 1961 - Apr lastSun 2:00 1:00 D
381 Rule Louisville 1941 only - Sep lastSun 2:00 0 S
382 Rule Louisville 1946 only - Jun 2 2:00 0 S
383 Rule Louisville 1950 1955 - Sep lastSun 2:00 0 S
384 Rule Louisville 1956 1960 - Oct lastSun 2:00 0 S
385 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
386 Zone America/Louisville -5:43:02 - LMT 1883 Nov 18 12:00
388 -6:00 Louisville C%sT 1942
390 -6:00 Louisville C%sT 1961 Jul 23 2:00
392 -5:00 US E%sT 1974 Jan 6 2:00
393 -6:00 1:00 CDT 1974 Oct 27 2:00
398 # From Bob Devine (1988-01-28):
399 # Michigan didn't observe DST from 1968 to 1973.
401 # From Paul Eggert (1995-12-19):
402 # Shanks writes that Michigan started using standard time on 1885 Sep 18,
403 # but Howse writes that Detroit kept
405 # local time until 1900 when the City Council decreed that clocks should
406 # be put back twenty-eight minutes to Central Standard Time. Half the
407 # city obeyed, half refused. After considerable debate, the decision
408 # was rescinded and the city reverted to Sun time. A derisive offer to
409 # erect a sundial in front of the city hall was referred to the
410 # Committee on Sewers. Then, in 1905, Central time was adopted
413 # This story is too entertaining to be false, so go with Howse over Shanks.
415 # Most of Michigan observed DST from 1973 on, but was a bit late in 1975.
416 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER
417 Rule Detroit 1948 only - Apr lastSun 2:00 1:00 D
418 Rule Detroit 1948 only - Sep lastSun 2:00 0 S
419 Rule Detroit 1967 only - Jun 14 2:00 1:00 D
420 Rule Detroit 1967 only - Oct lastSun 2:00 0 S
421 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
422 Zone America/Detroit -5:32:11 - LMT 1905
423 -6:00 - CST 1915 May 15 2:00
426 -5:00 Detroit E%sT 1973
428 -5:00 - EST 1975 Apr 27 2:00
431 # The Michigan border with Wisconsin switched from EST to CST/CDT in 1973.
432 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER
433 Rule Menominee 1946 only - Apr lastSun 2:00 1:00 D
434 Rule Menominee 1946 only - Sep lastSun 2:00 0 S
435 Rule Menominee 1966 only - Apr lastSun 2:00 1:00 D
436 Rule Menominee 1966 only - Oct lastSun 2:00 0 S
437 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
438 Zone America/Menominee -5:50:27 - LMT 1885 Sep 18 12:00
440 -6:00 Menominee C%sT 1969 Apr 27 2:00
441 -5:00 - EST 1973 Apr 29 2:00
445 # claimed by US under the provisions of the 1856 Guano Islands Act
446 # also claimed by Haiti
447 # occupied 1857/1900 by the Navassa Phosphate Co
448 # US lighthouse 1917/1997-01
449 # currently uninhabited
450 # see Mark Fineman, ``An Isle Rich in Guano and Discord'',
451 # _Los Angeles Times_ (1998-11-10), A1, A10; it cites
452 # Jimmy Skaggs, _The Great Guano Rush_ (1994).
454 # Old names, for S5 users
456 # Link LINK-FROM LINK-TO
457 Link America/New_York EST5EDT
458 Link America/Chicago CST6CDT
459 Link America/Denver MST7MDT
460 Link America/Los_Angeles PST8PDT
461 Link America/Indianapolis EST
462 Link America/Phoenix MST
463 Link Pacific/Honolulu HST
465 ################################################################################
468 # From Paul Eggert <eggert@twinsun.com> (1996-11-22):
469 # A good source for time zone historical data outside the US is
470 # Thomas G. Shanks, The International Atlas (4th edition),
471 # San Diego: ACS Publications, Inc. (1995).
473 # Gwillim Law <LAW@encmail.encompass.com> writes that a good source
474 # for recent time zone data is the International Air Transport
475 # Association's Standard Schedules Information Manual (IATA SSIM),
476 # published semiannually. Law sent in several helpful summaries
477 # of the IATA's data after 1990.
479 # Except where otherwise noted, Shanks is the source for entries through 1990,
480 # and IATA SSIM is the source for entries after 1990.
482 # Another source occasionally used is Edward W. Whitman, World Time Differences,
483 # Whitman Publishing Co, 2 Niagara Av, Ealing, London (undated), which
484 # I found in the UCLA library.
486 # See the `europe' file for Greenland.
490 # From Alain LaBont<e'> <ALB@immedia.ca> (1994-11-14):
491 # I post here the time zone abbreviations standardized in Canada
492 # for both English and French in the CAN/CSA-Z234.4-89 standard....
494 # UTC Standard time Daylight savings time
495 # offset French English French English
506 # HN: Heure Normale ST: Standard Time
507 # HA: Heure Avanc<e'>e DT: Daylight saving Time
509 # A: de l'Atlantique Atlantic
510 # C: du Centre Central
511 # E: de l'Est Eastern
514 # P: du Pacifique Pacific
519 # From Paul Eggert <eggert@twinsun.com> (1994-11-22):
520 # Alas, this sort of thing must be handled by localization software.
522 # The data for Canada are all from Shanks (1991).
525 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
526 Rule Canada 1918 only - Apr 14 2:00 1:00 D
527 Rule Canada 1918 only - Oct 31 2:00 0 S
528 Rule Canada 1942 only - Feb 9 2:00 1:00 D
529 Rule Canada 1945 only - Sep 30 2:00 0 S
530 Rule Canada 1974 1986 - Apr lastSun 2:00 1:00 D
531 Rule Canada 1974 max - Oct lastSun 2:00 0 S
532 Rule Canada 1987 max - Apr Sun>=1 2:00 1:00 D
535 # Newfoundland (except Labrador)
537 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
538 Rule StJohns 1917 1918 - Apr Sun>=8 2:00 1:00 D
539 Rule StJohns 1917 only - Sep 17 2:00 0 S
540 Rule StJohns 1918 only - Oct 31 2:00 0 S
541 # Whitman gives 1919 Apr 5 and 1920 Apr 5; go with Shanks.
542 Rule StJohns 1919 only - May 5 23:00 1:00 D
543 Rule StJohns 1919 only - Aug 12 23:00 0 S
544 # For 1931-1935 Whitman gives Apr same date; go with Shanks.
545 Rule StJohns 1920 1935 - May Sun>=1 23:00 1:00 D
546 Rule StJohns 1920 1935 - Oct lastSun 23:00 0 S
547 # For 1936-1941 Shanks gives May Mon>=9 and Oct Mon>=2; go with Whitman.
548 Rule StJohns 1936 1941 - May Sun>=8 0:00 1:00 D
549 Rule StJohns 1936 1941 - Oct Sun>=1 0:00 0 S
550 # Shanks gives 1942 May 11 - 1945 Sep 30; go with Whitman.
551 Rule StJohns 1942 only - Mar 1 0:00 1:00 D
552 Rule StJohns 1942 only - Dec 31 0:00 0 S
553 Rule StJohns 1943 only - May 30 0:00 1:00 D
554 Rule StJohns 1943 only - Sep 5 0:00 0 S
555 Rule StJohns 1944 only - Jul 10 0:00 1:00 D
556 Rule StJohns 1944 only - Sep 2 0:00 0 S
557 Rule StJohns 1945 only - Jan 1 0:00 1:00 D
558 Rule StJohns 1945 only - Oct 7 2:00 0 S
559 # For 1946-9 Whitman gives May 5,4,9,1 - Oct 1,5,3,2, and for 1950 he gives
560 # Apr 30 - Sep 24; go with Shanks.
561 Rule StJohns 1946 1950 - May Sun>=8 2:00 1:00 D
562 Rule StJohns 1946 1950 - Oct Sun>=2 2:00 0 S
563 Rule StJohns 1951 1986 - Apr lastSun 2:00 1:00 D
564 Rule StJohns 1951 1959 - Sep lastSun 2:00 0 S
565 Rule StJohns 1960 max - Oct lastSun 2:00 0 S
566 Rule StJohns 1987 only - Apr Sun>=1 2:00 1:00 D
567 Rule StJohns 1988 only - Apr Sun>=1 2:00 2:00 DD
568 Rule StJohns 1989 max - Apr Sun>=1 2:00 1:00 D
569 # St John's has an apostrophe, but Posix file names can't have apostrophes.
570 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
571 Zone America/St_Johns -3:30:52 - LMT 1884
572 -3:30:52 StJohns N%sT 1935 Mar 30
578 # The name `Happy Valley-Goose Bay' is too long; use `Goose Bay'.
579 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
580 Zone America/Goose_Bay -4:01:40 - LMT 1884 # Happy Valley-Goose Bay
581 -3:30:52 StJohns NST 1919
582 -3:30:52 - NST 1935 Mar 30
584 -3:30 StJohns N%sT 1966 Mar 15 2:00
588 # west Labrador, New Brunswick, Nova Scotia, Prince Edward I
590 # From Paul Eggert (1996-06-12):
591 # Shanks writes that since 1970 most of this region has been like Halifax.
592 # Many locales did not observe peacetime DST until 1972;
593 # Glace Bay, NS is the largest that we know of.
594 # Shanks also writes that Liverpool, NS was the only town in Canada to observe
595 # DST in 1971 but not 1970; for now we'll assume this is a typo.
597 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
598 Rule Halifax 1916 only - Apr 1 0:00 1:00 D
599 Rule Halifax 1916 only - Oct 1 0:00 0 S
600 Rule Halifax 1918 only - Apr 14 2:00 1:00 D
601 Rule Halifax 1918 only - Oct 31 2:00 0 S
602 Rule Halifax 1920 only - May 9 0:00 1:00 D
603 Rule Halifax 1920 only - Aug 29 0:00 0 S
604 Rule Halifax 1921 only - May 6 0:00 1:00 D
605 Rule Halifax 1921 1922 - Sep 5 0:00 0 S
606 Rule Halifax 1922 only - Apr 30 0:00 1:00 D
607 Rule Halifax 1923 1925 - May Sun>=1 0:00 1:00 D
608 Rule Halifax 1923 only - Sep 4 0:00 0 S
609 Rule Halifax 1924 only - Sep 15 0:00 0 S
610 Rule Halifax 1925 only - Sep 28 0:00 0 S
611 Rule Halifax 1926 only - May 16 0:00 1:00 D
612 Rule Halifax 1926 only - Sep 13 0:00 0 S
613 Rule Halifax 1927 only - May 1 0:00 1:00 D
614 Rule Halifax 1927 only - Sep 26 0:00 0 S
615 Rule Halifax 1928 1931 - May Sun>=8 0:00 1:00 D
616 Rule Halifax 1928 only - Sep 9 0:00 0 S
617 Rule Halifax 1929 only - Sep 3 0:00 0 S
618 Rule Halifax 1930 only - Sep 15 0:00 0 S
619 Rule Halifax 1931 1932 - Sep Mon>=24 0:00 0 S
620 Rule Halifax 1933 only - Apr 30 0:00 1:00 D
621 Rule Halifax 1933 only - Oct 2 0:00 0 S
622 Rule Halifax 1934 only - May 20 0:00 1:00 D
623 Rule Halifax 1934 only - Sep 16 0:00 0 S
624 Rule Halifax 1935 only - Jun 2 0:00 1:00 D
625 Rule Halifax 1935 only - Sep 30 0:00 0 S
626 Rule Halifax 1936 only - Jun 1 0:00 1:00 D
627 Rule Halifax 1936 only - Sep 14 0:00 0 S
628 Rule Halifax 1937 1938 - May Sun>=1 0:00 1:00 D
629 Rule Halifax 1937 1941 - Sep Mon>=24 0:00 0 S
630 Rule Halifax 1939 only - May 28 0:00 1:00 D
631 Rule Halifax 1940 1941 - May Sun>=1 0:00 1:00 D
632 Rule Halifax 1942 only - Feb 9 2:00 1:00 D
633 Rule Halifax 1945 1959 - Sep lastSun 2:00 0 S
634 Rule Halifax 1946 1959 - Apr lastSun 2:00 1:00 D
635 Rule Halifax 1962 1986 - Apr lastSun 2:00 1:00 D
636 Rule Halifax 1962 max - Oct lastSun 2:00 0 S
637 Rule Halifax 1987 max - Apr Sun>=1 2:00 1:00 D
638 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
639 Zone America/Halifax -4:14:24 - LMT 1902 Jun 15
641 Zone America/Glace_Bay -3:59:48 - LMT 1902 Jun 15
642 -4:00 Canada A%sT 1953
643 -4:00 Halifax A%sT 1954
650 # From Paul Eggert (1996-06-12):
651 # Shanks writes that since 1970 most of this region has been like Montreal.
652 # Thunder Bay skipped DST in 1973.
653 # Many smaller locales did not observe peacetime DST until 1974;
654 # Nipigon (EST) and Rainy River (CST) are the largest that we know of.
655 # Far west Ontario is like Winnipeg; far east Quebec is like Halifax.
657 # From Paul Eggert (1997-10-17):
658 # msb@sq.com writes that an article in the 1997-10-14 Toronto Star
659 # says that Atikokan, Ontario currently does not observe DST,
660 # but will vote on 11-10 whether to use EST/EDT.
661 # He also writes that the
662 # <a href="http://www.gov.on.ca/MBS/english/publications/statregs/conttext.html">
663 # Ontario Time Act (1990, Chapter T.9)
665 # says that Ontario east of 90W uses EST/EDT, and west of 90W uses CST/CDT.
666 # Officially Atikokan is therefore on CST/CDT, and most likely this report
667 # concerns a non-official time observed as a matter of local practice.
668 # For what it's worth, Shanks (1995) says that Atikokan has agreed with
669 # Rainy River ever since standard time was introduced.
671 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
672 Rule Mont 1917 only - Mar 25 2:00 1:00 D
673 Rule Mont 1917 only - Apr 24 0:00 0 S
674 Rule Mont 1918 only - Apr 14 2:00 1:00 D
675 Rule Mont 1918 only - Oct 31 2:00 0 S
676 Rule Mont 1919 only - Mar 31 2:30 1:00 D
677 Rule Mont 1919 only - Oct 25 2:30 0 S
678 Rule Mont 1920 only - May 2 2:30 1:00 D
679 Rule Mont 1920 only - Oct 3 2:30 0 S
680 Rule Mont 1921 only - May 1 2:00 1:00 D
681 Rule Mont 1921 only - Oct 2 2:30 0 S
682 Rule Mont 1922 only - Apr 30 2:00 1:00 D
683 Rule Mont 1922 only - Oct 1 2:30 0 S
684 Rule Mont 1924 only - May 17 2:00 1:00 D
685 Rule Mont 1924 1926 - Sep lastSun 2:30 0 S
686 Rule Mont 1925 1926 - May Sun>=1 2:00 1:00 D
687 Rule Mont 1927 only - May 1 0:00 1:00 D
688 Rule Mont 1927 1932 - Sep Sun>=25 0:00 0 S
689 Rule Mont 1928 1931 - Apr Sun>=25 0:00 1:00 D
690 Rule Mont 1932 only - May 1 0:00 1:00 D
691 Rule Mont 1933 1940 - Apr Sun>=24 0:00 1:00 D
692 Rule Mont 1933 only - Oct 1 0:00 0 S
693 Rule Mont 1934 1939 - Sep Sun>=24 0:00 0 S
694 Rule Mont 1945 1948 - Sep lastSun 2:00 0 S
695 Rule Mont 1946 1986 - Apr lastSun 2:00 1:00 D
696 Rule Mont 1949 1950 - Oct lastSun 2:00 0 S
697 Rule Mont 1951 1956 - Sep lastSun 2:00 0 S
698 Rule Mont 1957 max - Oct lastSun 2:00 0 S
699 Rule Mont 1987 max - Apr Sun>=1 2:00 1:00 D
700 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
701 Zone America/Montreal -4:54:16 - LMT 1884
703 Zone America/Thunder_Bay -5:57:00 - LMT 1895
704 -5:00 Canada E%sT 1970
708 Zone America/Nipigon -5:53:04 - LMT 1895
710 Zone America/Rainy_River -6:17:56 - LMT 1895
716 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
717 Rule Winn 1916 only - Apr 23 0:00 1:00 D
718 Rule Winn 1916 only - Sep 17 0:00 0 S
719 Rule Winn 1918 only - Apr 14 2:00 1:00 D
720 Rule Winn 1918 only - Oct 31 2:00 0 S
721 Rule Winn 1937 only - May 16 2:00 1:00 D
722 Rule Winn 1937 only - Sep 26 2:00 0 S
723 Rule Winn 1942 only - Feb 9 2:00 1:00 D
724 Rule Winn 1945 only - Sep lastSun 2:00 0 S
725 Rule Winn 1946 only - May 12 2:00 1:00 D
726 Rule Winn 1946 only - Oct 13 2:00 0 S
727 Rule Winn 1947 1949 - Apr lastSun 2:00 1:00 D
728 Rule Winn 1947 1949 - Sep lastSun 2:00 0 S
729 Rule Winn 1950 only - May 1 2:00 1:00 D
730 Rule Winn 1950 only - Sep 30 2:00 0 S
731 Rule Winn 1951 1960 - Apr lastSun 2:00 1:00 D
732 Rule Winn 1951 1958 - Sep lastSun 2:00 0 S
733 Rule Winn 1959 only - Oct lastSun 2:00 0 S
734 Rule Winn 1960 only - Sep lastSun 2:00 0 S
735 Rule Winn 1963 only - Apr lastSun 2:00 1:00 D
736 Rule Winn 1963 only - Sep 22 2:00 0 S
737 Rule Winn 1966 1986 - Apr lastSun 2:00 1:00 D
738 Rule Winn 1966 max - Oct lastSun 2:00 0 S
739 Rule Winn 1987 max - Apr Sun>=1 2:00 1:00 D
740 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
741 Zone America/Winnipeg -6:28:36 - LMT 1887 Jul 16
747 # From Paul Eggert (1996-06-12):
748 # Shanks writes that since 1970 most of this region has been like Regina.
749 # Some western towns (e.g. Swift Current) switched from MST/MDT to CST in 1972.
750 # Other western towns (e.g. Lloydminster) are like Edmonton.
752 # From W. Jones <jones@skdad.usask.ca> (1992-11-06):
753 # The. . .below is based on information I got from our law library, the
754 # provincial archives, and the provincial Community Services department.
755 # A precise history would require digging through newspaper archives, and
756 # since you didn't say what you wanted, I didn't bother.
758 # Saskatchewan is split by a time zone meridian (105W) and over the years
759 # the boundary became pretty ragged as communities near it reevaluated
760 # their affiliations in one direction or the other. In 1965 a provincial
761 # referendum favoured legislating common time practices.
763 # On 15 April 1966 the Time Act (c. T-14, Revised Statutes of
764 # Saskatchewan 1978) was proclaimed, and established that the eastern
765 # part of Saskatchewan would use CST year round, that districts in
766 # northwest Saskatchewan would by default follow CST but could opt to
767 # follow Mountain Time rules (thus 1 hour difference in the winter and
768 # zero in the summer), and that districts in southwest Saskatchewan would
769 # by default follow MT but could opt to follow CST.
771 # It took a few years for the dust to settle (I know one story of a town
772 # on one time zone having its school in another, such that a mom had to
773 # serve her family lunch in two shifts), but presently it seems that only
774 # a few towns on the border with Alberta (e.g. Lloydminster) follow MT
775 # rules any more; all other districts appear to have used CST year round
776 # since sometime in the 1960s.
778 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
779 Rule Regina 1918 only - Apr 14 2:00 1:00 D
780 Rule Regina 1918 only - Oct 31 2:00 0 S
781 Rule Regina 1930 1934 - May Sun>=1 0:00 1:00 D
782 Rule Regina 1930 1934 - Oct Sun>=1 0:00 0 S
783 Rule Regina 1937 1941 - Apr Sun>=8 0:00 1:00 D
784 Rule Regina 1937 only - Oct Sun>=8 0:00 0 S
785 Rule Regina 1938 only - Oct Sun>=1 0:00 0 S
786 Rule Regina 1939 1941 - Oct Sun>=8 0:00 0 S
787 Rule Regina 1942 only - Feb 9 2:00 1:00 D
788 Rule Regina 1945 only - Sep lastSun 2:00 0 S
789 Rule Regina 1946 only - Apr Sun>=8 2:00 1:00 D
790 Rule Regina 1946 only - Oct Sun>=8 2:00 0 S
791 Rule Regina 1947 1959 - Apr lastSun 2:00 1:00 D
792 Rule Regina 1947 1958 - Sep lastSun 2:00 0 S
793 Rule Regina 1959 only - Oct lastSun 2:00 0 S
795 Rule Swift 1957 only - Apr lastSun 2:00 1:00 D
796 Rule Swift 1957 only - Oct lastSun 2:00 0 S
797 Rule Swift 1959 1961 - Apr lastSun 2:00 1:00 D
798 Rule Swift 1959 only - Oct lastSun 2:00 0 S
799 Rule Swift 1960 1961 - Sep lastSun 2:00 0 S
800 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
801 Zone America/Regina -6:58:36 - LMT 1905 Sep
802 -7:00 Regina M%sT 1960 Apr lastSun 2:00
804 Zone America/Swift_Current -7:11:20 - LMT 1905 Sep
805 -7:00 Canada M%sT 1946 Apr lastSun 2:00
806 -7:00 Regina M%sT 1950
807 -7:00 Swift M%sT 1972 Apr lastSun 2:00
813 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
814 Rule Edm 1918 1919 - Apr Sun>=8 2:00 1:00 D
815 Rule Edm 1918 only - Oct 31 2:00 0 S
816 Rule Edm 1919 only - May 27 2:00 0 S
817 Rule Edm 1920 1923 - Apr lastSun 2:00 1:00 D
818 Rule Edm 1920 only - Oct lastSun 2:00 0 S
819 Rule Edm 1921 1923 - Sep lastSun 2:00 0 S
820 Rule Edm 1942 only - Feb 9 2:00 1:00 D
821 Rule Edm 1945 only - Sep lastSun 2:00 0 S
822 Rule Edm 1947 only - Apr lastSun 2:00 1:00 D
823 Rule Edm 1947 only - Sep lastSun 2:00 0 S
824 Rule Edm 1967 only - Apr lastSun 2:00 1:00 D
825 Rule Edm 1967 only - Oct lastSun 2:00 0 S
826 Rule Edm 1969 only - Apr lastSun 2:00 1:00 D
827 Rule Edm 1969 only - Oct lastSun 2:00 0 S
828 Rule Edm 1972 1986 - Apr lastSun 2:00 1:00 D
829 Rule Edm 1972 max - Oct lastSun 2:00 0 S
830 Rule Edm 1987 max - Apr Sun>=1 2:00 1:00 D
831 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
832 Zone America/Edmonton -7:33:52 - LMT 1906 Sep
838 # From Paul Eggert (1996-06-12):
839 # Shanks writes that since 1970 most of this region has been like Vancouver.
840 # Dawswon Creek uses MST. Much of east BC is like Edmonton.
842 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
843 Rule Vanc 1918 only - Apr 14 2:00 1:00 D
844 Rule Vanc 1918 only - Oct 31 2:00 0 S
845 Rule Vanc 1942 only - Feb 9 2:00 1:00 D
846 Rule Vanc 1945 only - Sep 30 2:00 0 S
847 Rule Vanc 1946 1986 - Apr lastSun 2:00 1:00 D
848 Rule Vanc 1946 only - Oct 13 2:00 0 S
849 Rule Vanc 1947 1961 - Sep lastSun 2:00 0 S
850 Rule Vanc 1962 max - Oct lastSun 2:00 0 S
851 Rule Vanc 1987 max - Apr Sun>=1 2:00 1:00 D
852 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
853 Zone America/Vancouver -8:12:28 - LMT 1884
855 Zone America/Dawson_Creek -8:00:56 - LMT 1884
856 -8:00 Canada P%sT 1947
857 -8:00 Vanc P%sT 1972 Aug 30 2:00
861 # Northwest Territories, Nunavut, Yukon
863 # From Paul Eggert (1996-10-07):
864 # Dawson switched to PST in 1973. Inuvik switched to MST in 1979.
865 # Shanks's table for Watson Lake is corrupted, so we have no data there.
866 # Mathew Englander <mathew@io.org> (1996-10-07) gives the following refs:
867 # * 1967. Paragraph 28(34)(g) of the Interpretation Act, S.C. 1967-68,
868 # c. 7 defines Yukon standard time as UTC-9. This is still valid;
869 # see Interpretation Act, R.S.C. 1985, c. I-21, s. 35(1).
870 # * C.O. 1973/214 switched Yukon to PST on 1973-10-28 00:00.
871 # * O.I.C. 1980/02 established DST.
872 # * O.I.C. 1987/056 changed DST to Apr firstSun 2:00 to Oct lastSun 2:00.
873 # Shanks says Yukon's 1973-10-28 switch was at 2:00; go with Englander.
875 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
876 Rule NT_YK 1918 only - Apr 14 2:00 1:00 D
877 Rule NT_YK 1918 only - Oct 27 2:00 0 S
878 Rule NT_YK 1919 only - May 25 2:00 1:00 D
879 Rule NT_YK 1919 only - Nov 1 0:00 0 S
880 Rule NT_YK 1942 only - Feb 9 2:00 1:00 D
881 Rule NT_YK 1945 only - Sep 30 2:00 0 S
882 Rule NT_YK 1965 only - Apr lastSun 0:00 2:00 DD
883 Rule NT_YK 1965 only - Oct lastSun 2:00 0 S
884 Rule NT_YK 1980 1986 - Apr lastSun 2:00 1:00 D
885 Rule NT_YK 1980 max - Oct lastSun 2:00 0 S
886 Rule NT_YK 1987 max - Apr Sun>=1 2:00 1:00 D
887 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
888 Zone America/Pangnirtung -4:22:56 - LMT 1884
890 Zone America/Iqaluit -4:33:52 - LMT 1884 # Frobisher Bay
892 Zone America/Rankin_Inlet -6:08:40 - LMT 1884
894 Zone America/Yellowknife -7:37:24 - LMT 1884
896 Zone America/Inuvik -8:54:00 - LMT 1884
897 -8:00 NT_YK P%sT 1979 Apr lastSun 2:00
899 Zone America/Whitehorse -9:00:12 - LMT 1900 Aug 20
900 -9:00 NT_YK Y%sT 1966 Jul 1 2:00
902 Zone America/Dawson -9:17:40 - LMT 1900 Aug 20
903 -9:00 NT_YK Y%sT 1973 Oct 28 0:00
907 ###############################################################################
912 # Rules are from the Official Airline Guide, Worldwide Edition, for 1987.
913 # Rules [before] 1987 are unknown.
914 # The comments in the OAG say "Only Ensenada, Mexicale, San Felipe and Tijuana
915 # observe DST." This is presumably Baja California Norte, above 28th parallel,
916 # as listed there; [there is also] "Baja California Sur and N. Pacific
917 # Coast (States of Sinaloa and Sonora)."
919 # From Bob Devine (1988-01-28):
920 # The Federal District (where Mexico City is) has observed [DST] several
921 # times but not recently.
923 # I don't where to drawn the line in the North Baja area. 28th latitude
924 # sounds good -- but it may be higher (how far [d]o radio stations from
925 # San Diego affect culture?).
927 # The dates of DST probably go back to 1981. The rules are the same as
928 # US's. This is going to be a headache for US presidential electi[o]n years!
930 # From Arthur David Olson (1988-02-13)
931 # Since the 1981 starting date is only "probable," we'll keep the 1987
932 # starting date below.
934 # From U. S. Naval Observatory (1989-01-19):
935 # MEXICO BAJA CAL N 7 H BEHIND UTC BAJA CALIFORNIA SUR AND
936 # MEXICO BAJA CAL N N. PACIFIC COAST (STATES
937 # MEXICO BAJA CAL N OF SINALOA AND SONORA)
938 # MEXICO BAJA CAL N 8 H BEHIND UTC ABOVE 28TH PARALLEL APR 3
939 # MEXICO BAJA CAL N - OCT 29
940 # MEXICO BAJA CAL N 7 H BEHIND UTC ABOVE 28TH PARALLEL APR 3
941 # MEXICO BAJA CAL N - 0CT 29
942 # MEXICO 6 H BEHIND UTC STATES OF DURANGO,
943 # MEXICO COAHUILA, NUEVO LEON,
945 # MEXICO 5 H BEHIND UTC STATES OF DURANGO,
946 # MEXICO COAHUILA, NUEVO LEON,
947 # MEXICO TAMAULIPAS APR 3 - OCT 29
948 # MEXICO 6 H BEHIND UTC GENERAL MEXICO, STATES OF
949 # MEXICO CAMPECHE, QUINTANA ROO AND
952 # From Arthur David Olson (1989-01-21):
953 # April 3 fell on a Sunday in 1988; October 29 fell on a Sunday in 1989. Ahem.
954 # USNO claims there should be four Mexican zones rather than three:
955 # a zone that's GMT-8 with DST; a zone that's always GMT-7;
956 # a zone that's GMT-6 with DST; and a zone that's always GMT-6.
958 # From Paul Eggert <eggert@twinsun.com> (1993-11-18):
959 # Shanks also says there are four zones, but disagrees about the fourth.
960 # Instead of GMT-6 with DST, he says there's GMT-8 without DST.
962 # From Alan Perry <alan.perry@eng.sun.com> (1996-02-15):
963 # A guy from our Mexico subsidiary finally found the Presidential Decree
964 # outlining the timezone changes in Mexico.
966 # ------------- Begin Forwarded Message -------------
968 # I finally got my hands on the Official Presidential Decree that sets up the
969 # rules for the DST changes. The rules are:
971 # 1. The country is divided in 3 timezones:
972 # - Baja California Norte (the Mexico/BajaNorte TZ)
973 # - Baja California Sur, Nayarit, Sinaloa and Sonora (the Mexico/BajaSur TZ)
974 # - The rest of the country (the Mexico/General TZ)
976 # 2. From the first Sunday in April at 2:00 AM to the last Sunday in October
977 # at 2:00 AM, the times in each zone are as follows:
982 # 3. The rest of the year, the times are as follows:
987 # The Decree was published in Mexico's Official Newspaper on January 4th.
989 # -------------- End Forwarded Message --------------
990 # From Paul Eggert (1996-06-12):
991 # For an English translation of the decree, see
992 # <a href="http://mexico-travel.com/extra/timezone_eng.html">
993 # ``Diario Oficial: Time Zone Changeover'' (1996-01-04).
996 # From Rives McDow (1998-10-08):
997 # The State of Quintana Roo has reverted back to central STD and DST times
998 # (i.e. UTC -0600 and -0500 as of 1998-08-02).
1000 # From Shanks (1991):
1001 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
1002 Rule Mexico 1939 only - Feb 5 0:00 1:00 D
1003 Rule Mexico 1939 only - Jun 25 0:00 0 S
1004 Rule Mexico 1940 only - Dec 9 0:00 1:00 D
1005 Rule Mexico 1941 only - Apr 1 0:00 0 S
1006 Rule Mexico 1943 only - Dec 16 0:00 1:00 D
1007 Rule Mexico 1944 only - May 1 0:00 0 S
1008 Rule Mexico 1950 only - Feb 12 0:00 1:00 D
1009 Rule Mexico 1950 only - Jul 30 0:00 0 S
1010 Rule Mexico 1996 max - Apr Sun>=1 2:00 1:00 D
1011 Rule Mexico 1996 max - Oct lastSun 2:00 0 S
1013 Rule BajaN 1950 1966 - Apr lastSun 2:00 1:00 D
1014 Rule BajaN 1950 1961 - Sep lastSun 2:00 0 S
1015 Rule BajaN 1961 1966 - Oct lastSun 2:00 0 S
1016 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1018 Zone America/Cancun -5:47:04 - LMT 1922 Jan 1 1:12:42
1020 -6:00 Mexico C%sT 1997 Oct lastSun 2:00
1021 -5:00 Mexico E%sT 1998 Aug 2 2:00
1024 Zone America/Mexico_City -6:36:36 - LMT 1922 Jan 1 0:23:24
1025 -7:00 - MST 1927 Jun 10 23:00
1026 -6:00 - CST 1930 Nov 15
1027 -7:00 - MST 1931 May 1 23:00
1028 -6:00 - CST 1931 Oct
1029 -7:00 - MST 1932 Mar 30 23:00
1032 Zone America/Chihuahua -7:04:20 - LMT 1921 Dec 31 23:55:44
1033 -7:00 - MST 1927 Jun 10 23:00
1034 -6:00 - CST 1930 Nov 15
1035 -7:00 - MST 1931 May 1 23:00
1036 -6:00 - CST 1931 Oct
1037 -7:00 - MST 1932 Mar 30 23:00
1039 -6:00 Mexico C%sT 1998
1040 -6:00 - CST 1998 Apr Sun>=1 3:00
1042 # S Baja California, Nayarit, Sinaloa, Sonora
1043 Zone America/Mazatlan -7:05:40 - LMT 1921 Dec 31 23:54:20
1044 -7:00 - MST 1927 Jun 10 23:00
1045 -6:00 - CST 1930 Nov 15
1046 -7:00 - MST 1931 May 1 23:00
1047 -6:00 - CST 1931 Oct
1048 -7:00 - MST 1932 Mar 30 23:00
1049 -6:00 - CST 1942 Apr
1050 -7:00 - MST 1949 Jan 14
1054 Zone America/Tijuana -7:48:04 - LMT 1922 Jan 1 0:11:56
1055 -8:00 - PST 1927 Jun 10 23:00
1056 -7:00 - MST 1930 Nov 16
1057 -8:00 - PST 1942 Apr
1058 -7:00 - MST 1949 Jan 14
1059 -8:00 BajaN P%sT 1967 Apr lastSun 2:00
1063 Zone America/Ensenada -7:46:28 - LMT 1922 Jan 1 0:13:32
1064 -8:00 - PST 1927 Jun 10 23:00
1065 -7:00 - MST 1930 Nov 16
1066 -8:00 - PST 1942 Apr
1067 -7:00 - MST 1949 Jan 14
1074 ###############################################################################
1077 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1078 Zone America/Anguilla -4:12:16 - LMT 1912 Mar 2
1081 # Antigua and Barbuda
1082 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1083 Zone America/Antigua -4:07:12 - LMT 1912 Mar 2
1088 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
1089 Rule Bahamas 1964 max - Oct lastSun 2:00 0 S
1090 Rule Bahamas 1964 1986 - Apr lastSun 2:00 1:00 D
1091 Rule Bahamas 1987 max - Apr Sun>=1 2:00 1:00 D
1092 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1093 Zone America/Nassau -5:09:24 - LMT 1912 Mar 2
1097 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
1098 Rule Barb 1977 only - Jun 12 2:00 1:00 D
1099 Rule Barb 1977 1978 - Oct Sun>=1 2:00 0 S
1100 Rule Barb 1978 1980 - Apr Sun>=15 2:00 1:00 D
1101 Rule Barb 1979 only - Sep 30 2:00 0 S
1102 Rule Barb 1980 only - Sep 25 2:00 0 S
1103 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1104 Zone America/Barbados -3:58:28 - LMT 1924 # Bridgetown
1105 -3:58:28 - BMT 1932 # Bridgetown Mean Time
1109 # Whitman entirely disagrees with Shanks; go with Shanks.
1110 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
1111 Rule Belize 1918 1942 - Oct Sun>=2 0:00 0:30 HD
1112 Rule Belize 1919 1943 - Feb Sun>=9 0:00 0 S
1113 Rule Belize 1973 only - Dec 5 0:00 1:00 D
1114 Rule Belize 1974 only - Feb 9 0:00 0 S
1115 Rule Belize 1982 only - Dec 18 0:00 1:00 D
1116 Rule Belize 1983 only - Feb 12 0:00 0 S
1117 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1118 Zone America/Belize -5:52:48 - LMT 1912 Apr
1122 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1123 Zone Atlantic/Bermuda -4:19:04 - LMT 1930 Jan 1 2:00 # Hamilton
1124 -4:00 - AST 1974 Apr 28 2:00
1128 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1129 Zone America/Cayman -5:25:32 - LMT 1890 # Georgetown
1130 -5:07:12 - KMT 1912 Feb # Kingston Mean Time
1134 # Shanks gives some very odd dates for 1991, and stops there.
1135 # For now, we won't guess further.
1136 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
1137 Rule CR 1979 1980 - Feb lastSun 0:00 1:00 D
1138 Rule CR 1979 1980 - Jun Sun>=1 0:00 0 S
1139 Rule CR 1991 1992 - Jan Sat>=15 0:00 1:00 D
1140 # IATA SSIM (1991-09) says the following was at 1:00; go with Shanks.
1141 Rule CR 1991 only - Jul 1 0:00 0 S
1142 Rule CR 1992 only - Mar 15 0:00 0 S
1143 # There are too many San Joses elsewhere, so we'll use `Costa Rica'.
1144 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1145 Zone America/Costa_Rica -5:36:20 - LMT 1890 # San Jose
1146 -5:36 - SJMT 1921 Jan 15 # San Jose Mean Time
1149 # no information; probably like America/Costa_Rica
1153 # From Bob Devine (1988-01-28):
1154 # . . .DST is from 2nd Sunday in May to 2nd Sunday in October since 1981.
1155 # Change at midnight. In 1979 & 1980, started at 3rd Sunday in March
1158 # From U. S. Naval Observatory (1989-01-19):
1159 # CUBA 5 H BEHIND UTC
1160 # CUBA 4 H BEHIND UTC MAR 20 - OCT 8
1162 # From Shanks (1991):
1163 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
1164 Rule Cuba 1928 only - Jun 10 0:00 1:00 D
1165 Rule Cuba 1928 only - Oct 10 0:00 0 S
1166 Rule Cuba 1940 1942 - Jun Sun>=1 0:00 1:00 D
1167 Rule Cuba 1940 1942 - Sep Sun>=1 0:00 0 S
1168 Rule Cuba 1945 1946 - Jun Sun>=1 0:00 1:00 D
1169 Rule Cuba 1945 1946 - Sep Sun>=1 0:00 0 S
1170 Rule Cuba 1965 only - Jun 1 0:00 1:00 D
1171 Rule Cuba 1965 only - Sep 30 0:00 0 S
1172 Rule Cuba 1966 only - May 29 0:00 1:00 D
1173 Rule Cuba 1966 only - Oct 2 0:00 0 S
1174 Rule Cuba 1967 only - Apr 8 0:00 1:00 D
1175 Rule Cuba 1967 1968 - Sep Sun>=8 0:00 0 S
1176 Rule Cuba 1968 only - Apr 14 0:00 1:00 D
1177 Rule Cuba 1969 1977 - Apr lastSun 0:00 1:00 D
1178 Rule Cuba 1969 1971 - Oct lastSun 0:00 0 S
1179 Rule Cuba 1972 1974 - Oct 8 0:00 0 S
1180 Rule Cuba 1975 1977 - Oct lastSun 0:00 0 S
1181 Rule Cuba 1978 only - May 7 0:00 1:00 D
1182 Rule Cuba 1978 1990 - Oct Sun>=8 0:00 0 S
1183 Rule Cuba 1979 1980 - Mar Sun>=15 0:00 1:00 D
1184 Rule Cuba 1981 1985 - May Sun>=5 0:00 1:00 D
1185 Rule Cuba 1986 1989 - Mar Sun>=14 0:00 1:00 D
1186 Rule Cuba 1990 1997 - Apr Sun>=1 0:00 1:00 D
1187 Rule Cuba 1991 1995 - Oct Sun>=8 0:00s 0 S
1188 Rule Cuba 1996 only - Oct 6 0:00s 0 S
1189 Rule Cuba 1997 only - Oct 12 0:00s 0 S
1190 Rule Cuba 1998 only - Mar 29 0:00 1:00 D
1191 Rule Cuba 1998 max - Oct lastSun 0:00s 0 S
1192 Rule Cuba 1999 max - Apr Sun>=1 0:00s 1:00 D
1194 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1195 Zone America/Havana -5:29:28 - LMT 1890
1196 -5:30 - HMT 1925 Jul 19 12:00 # Havana MT
1200 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1201 Zone America/Dominica -4:05:36 - LMT 1911 Jul 1 0:01 # Roseau
1204 # Dominican Republic
1205 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
1206 Rule DR 1966 only - Oct 30 0:00 1:00 D
1207 Rule DR 1967 only - Feb 28 0:00 0 S
1208 Rule DR 1969 1973 - Oct lastSun 0:00 0:30 HD
1209 Rule DR 1970 only - Feb 21 0:00 0 S
1210 Rule DR 1971 only - Jan 20 0:00 0 S
1211 Rule DR 1972 1974 - Jan 21 0:00 0 S
1212 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1213 Zone America/Santo_Domingo -4:39:36 - LMT 1890
1214 -4:40 - SDMT 1933 Apr 1 12:00 # S. Dom. MT
1215 -5:00 DR E%sT 1974 Oct 27
1219 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
1220 Rule Salv 1987 1988 - May Sun>=1 0:00 1:00 D
1221 Rule Salv 1987 1988 - Sep lastSun 0:00 0 S
1222 # There are too many San Salvadors elsewhere, so we'll use `El Salvador'.
1223 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1224 Zone America/El_Salvador -5:56:48 - LMT 1921 # San Salvador
1228 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1229 Zone America/Grenada -4:07:00 - LMT 1911 Jul # St George's
1233 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1234 Zone America/Guadeloupe -4:06:08 - LMT 1911 Jun 8 # Pointe a Pitre
1238 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
1239 Rule Guat 1973 only - Nov 25 0:00 1:00 D
1240 Rule Guat 1974 only - Feb 24 0:00 0 S
1241 Rule Guat 1983 only - May 21 0:00 1:00 D
1242 Rule Guat 1983 only - Sep 22 0:00 0 S
1243 Rule Guat 1991 only - Mar 23 0:00 1:00 D
1244 Rule Guat 1991 only - Sep 7 0:00 0 S
1245 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1246 Zone America/Guatemala -6:02:04 - LMT 1918 Oct 5
1250 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
1251 Rule Haiti 1983 only - May 8 0:00 1:00 D
1252 Rule Haiti 1984 1987 - Apr lastSun 0:00 1:00 D
1253 Rule Haiti 1983 1987 - Oct lastSun 0:00 0 S
1254 # Shanks says AT is 2:00, but IATA SSIM (1991/1996) says 1:00s. Go with IATA.
1255 Rule Haiti 1988 1997 - Apr Sun>=1 1:00s 1:00 D
1256 Rule Haiti 1988 1997 - Oct lastSun 1:00s 0 S
1257 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1258 Zone America/Port-au-Prince -4:49:20 - LMT 1890
1259 -4:49 - PPMT 1917 Jan 24 12:00 # P-a-P MT
1263 # Shanks says 1921 Jan 1; go with Whitman's more precise Apr 1.
1264 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1265 Zone America/Tegucigalpa -5:48:52 - LMT 1921 Apr
1268 # Great Swan I ceded by US to Honduras in 1972
1272 # From Bob Devine (1988-01-28):
1275 # From U. S. Naval Observatory (1989-01-19):
1276 # JAMAICA 5 H BEHIND UTC
1278 # From Shanks (1991):
1279 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1280 Zone America/Jamaica -5:07:12 - LMT 1890 # Kingston
1281 -5:07:12 - KMT 1912 Feb # Kingston Mean Time
1282 -5:00 - EST 1974 Jan 6 2:00
1287 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1288 Zone America/Martinique -4:04:20 - LMT 1890 # Fort-de-France
1289 -4:04 - FFMT 1911 May # Fort-de-France MT
1290 -4:00 - AST 1980 Apr 6
1291 -4:00 1:00 ADT 1980 Sep 28
1295 # From Paul Eggert (1997-08-31):
1296 # Recent volcanic eruptions have forced evacuation of Plymouth, the capital.
1297 # Luckily, Olveston, the current de facto capital, has the same longitude.
1298 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1299 Zone America/Montserrat -4:08:52 - LMT 1911 Jul 1 0:01 # Olveston
1304 # From Steffen Thorsen (1998-12-29):
1305 # Nicaragua seems to be back at -6:00 but I have not been able to find when
1306 # they changed from -5:00.
1308 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
1309 Rule Nic 1979 1980 - Mar Sun>=16 0:00 1:00 D
1310 Rule Nic 1979 1980 - Jun Mon>=23 0:00 0 S
1311 Rule Nic 1992 only - Jan 1 4:00 1:00 D
1312 Rule Nic 1992 only - Sep 24 0:00 0 S
1313 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1314 Zone America/Managua -5:45:08 - LMT 1890
1315 -5:45 - MMT 1934 Jun 23 # Managua Mean Time
1316 -6:00 - CST 1973 May
1317 -5:00 - EST 1975 Feb 16
1318 -6:00 Nic C%sT 1993 Jan 1 4:00
1319 -5:00 - EST 1998 Dec
1323 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1324 Zone America/Panama -5:18:08 - LMT 1890
1325 -5:20 - PMT 1908 Apr 22 # Panama Mean Time
1329 # There are too many San Juans elsewhere, so we'll use `Puerto_Rico'.
1330 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1331 Zone America/Puerto_Rico -4:24:25 - LMT 1899 Mar 28 12:00 # San Juan
1332 -4:00 - AST 1942 May 3
1333 -4:00 1:00 AWT 1945 Sep 30 2:00
1337 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1338 Zone America/St_Kitts -4:10:52 - LMT 1912 Mar 2 # Basseterre
1342 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1343 Zone America/St_Lucia -4:04:00 - LMT 1890 # Castries
1344 -4:04 - CMT 1912 # Castries Mean Time
1347 # St Pierre and Miquelon
1348 # There are too many St Pierres elsewhere, so we'll use `Miquelon'.
1349 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1350 Zone America/Miquelon -3:44:40 - LMT 1911 May 15 # St Pierre
1351 -4:00 - AST 1980 May
1352 -3:00 Mont PM%sT # Pierre & Miquelon Time
1354 # St Vincent and the Grenadines
1355 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1356 Zone America/St_Vincent -4:04:56 - LMT 1890 # Kingstown
1357 -4:04:56 - KMT 1912 # Kingstown Mean Time
1361 # From Paul Eggert (1998-08-06):
1362 # Shanks says they use US DST rules, but IATA SSIM (1991/1998)
1363 # says they switch at midnight. Go with IATA SSIM.
1364 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
1365 Rule TC 1979 1986 - Apr lastSun 0:00 1:00 D
1366 Rule TC 1979 max - Oct lastSun 0:00 0 S
1367 Rule TC 1987 max - Apr Sun>=1 0:00 1:00 D
1368 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1369 Zone America/Grand_Turk -4:44:32 - LMT 1890
1370 -5:07:12 - KMT 1912 Feb # Kingston Mean Time
1374 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1375 Zone America/Tortola -4:18:28 - LMT 1911 Jul # Road Town
1379 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1380 Zone America/St_Thomas -4:19:44 - LMT 1911 Jul # Charlotte Amalie