1 # @(#)northamerica 7.70
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 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER
212 Rule NYC 1920 only - Mar lastSun 2:00 1:00 D
213 Rule NYC 1920 only - Oct lastSun 2:00 0 S
214 Rule NYC 1921 1966 - Apr lastSun 2:00 1:00 D
215 Rule NYC 1921 1954 - Sep lastSun 2:00 0 S
216 Rule NYC 1955 1966 - Oct lastSun 2:00 0 S
217 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
218 Zone America/New_York -4:56:02 - LMT 1883 Nov 18 12:00
225 # US central time, represented by Chicago
227 # Alabama, Arkansas, Florida panhandle (Bay, Calhoun, Escambia,
228 # Gulf, Holmes, Jackson, Okaloosa, Santa Rosa, Walton, and
229 # Washington counties), Illinois, western Indiana
230 # (Gibson, Jasper, Lake, LaPorte, Newton, Porter, Posey, Spencer,
231 # Vanderburgh, and Warrick counties), Iowa, most of Kansas, western
232 # Kentucky, Louisiana, Minnesota, Mississippi, Missouri, eastern
233 # Nebraska, eastern North Dakota, Oklahoma, eastern South Dakota,
234 # western Tennessee, most of Texas, Wisconsin
236 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER
237 Rule Chicago 1920 only - Jun 13 2:00 1:00 D
238 Rule Chicago 1920 1921 - Oct lastSun 2:00 0 S
239 Rule Chicago 1921 only - Mar lastSun 2:00 1:00 D
240 Rule Chicago 1922 1966 - Apr lastSun 2:00 1:00 D
241 Rule Chicago 1922 1954 - Sep lastSun 2:00 0 S
242 Rule Chicago 1955 1966 - Oct lastSun 2:00 0 S
243 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
244 Zone America/Chicago -5:50:36 - LMT 1883 Nov 18 12:00
246 -6:00 Chicago C%sT 1936 Mar 1 2:00
247 -5:00 - EST 1936 Nov 15 2:00
248 -6:00 Chicago C%sT 1942
250 -6:00 Chicago C%sT 1967
252 # Oliver County, ND switched from mountain to central time on 1992-10-25.
253 Zone America/North_Dakota/Center -6:45:12 - LMT 1883 Nov 18 12:00
254 -7:00 US M%sT 1992 Oct 25 02:00
257 # US mountain time, represented by Denver
259 # Colorado, far western Kansas, Montana, western
260 # Nebraska, Nevada border (Jackpot, Owyhee, and Mountain City),
261 # New Mexico, southwestern North Dakota, far eastern Oregon,
262 # western South Dakota, far western Texas (El Paso County, Hudspeth County,
263 # and Pine Springs and Nickel Creek in Culberson County), Utah, Wyoming
265 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER
266 Rule Denver 1920 1921 - Mar lastSun 2:00 1:00 D
267 Rule Denver 1920 only - Oct lastSun 2:00 0 S
268 Rule Denver 1921 only - May 22 2:00 0 S
269 Rule Denver 1965 1966 - Apr lastSun 2:00 1:00 D
270 Rule Denver 1965 1966 - Oct lastSun 2:00 0 S
271 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
272 Zone America/Denver -6:59:56 - LMT 1883 Nov 18 12:00
274 -7:00 Denver M%sT 1942
276 -7:00 Denver M%sT 1967
279 # US Pacific time, represented by Los Angeles
281 # California, northern Idaho (Benewah, Bonner, Boundary, Clearwater,
282 # Idaho, Kootenai, Latah, Lewis, Nez Perce, and Shoshone counties),
283 # most of Nevada, most of Oregon, and Washington
285 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER
286 Rule CA 1948 only - Mar 14 2:00 1:00 D
287 Rule CA 1949 only - Jan 1 2:00 0 S
288 Rule CA 1950 1966 - Apr lastSun 2:00 1:00 D
289 Rule CA 1950 1961 - Sep lastSun 2:00 0 S
290 Rule CA 1962 1966 - Oct lastSun 2:00 0 S
291 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
292 Zone America/Los_Angeles -7:52:58 - LMT 1883 Nov 18 12:00
298 # AK%sT is the modern abbreviation for -9:00 per USNO.
300 # From Paul Eggert (2001-05-30):
301 # Howse writes that Alaska switched from the Julian to the Gregorian calendar,
302 # and from east-of-GMT to west-of-GMT days, when the US bought it from Russia.
303 # This was on 1867-10-18, a Friday; the previous day was 1867-10-06 Julian,
304 # also a Friday. Include only the time zone part of this transition,
305 # ignoring the switch from Julian to Gregorian, since we can't represent
306 # the Julian calendar.
308 # As far as we know, none of the exact locations mentioned below were
309 # permanently inhabited in 1867 by anyone using either calendar.
310 # (Yakutat was colonized by the Russians in 1799, but the settlement
311 # was destroyed in 1805 by a Yakutat-kon war party.) However, there
312 # were nearby inhabitants in some cases and for our purposes perhaps
313 # it's best to simply use the official transition.
315 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
316 Zone America/Juneau 15:02:19 - LMT 1867 Oct 18
317 -8:57:41 - LMT 1900 Aug 20 12:00
321 -8:00 US P%sT 1983 Oct 30 2:00
322 -9:00 US Y%sT 1983 Nov 30
324 Zone America/Yakutat 14:41:05 - LMT 1867 Oct 18
325 -9:18:55 - LMT 1900 Aug 20 12:00
329 -9:00 US Y%sT 1983 Nov 30
331 Zone America/Anchorage 14:00:24 - LMT 1867 Oct 18
332 -9:59:36 - LMT 1900 Aug 20 12:00
334 -10:00 US CAT/CAWT 1946
335 -10:00 - CAT 1967 Apr
337 -10:00 US AH%sT 1983 Oct 30 2:00
338 -9:00 US Y%sT 1983 Nov 30
340 Zone America/Nome 12:58:21 - LMT 1867 Oct 18
341 -11:01:38 - LMT 1900 Aug 20 12:00
344 -11:00 - NST 1967 Apr
346 -11:00 US B%sT 1983 Oct 30 2:00
347 -9:00 US Y%sT 1983 Nov 30
349 Zone America/Adak 12:13:21 - LMT 1867 Oct 18
350 -11:46:38 - LMT 1900 Aug 20 12:00
353 -11:00 - NST 1967 Apr
355 -11:00 US B%sT 1983 Oct 30 2:00
356 -10:00 US AH%sT 1983 Nov 30
358 # Shanks writes that part of southwest Alaska (e.g. Aniak)
359 # switched from -11:00 to -10:00 on 1968-09-22 at 02:00,
360 # and another part (e.g. Akiak) made the same switch five weeks later.
361 # These switches don't quite make our 1970 cutoff.
365 # From Arthur David Olson:
366 # And then there's Hawaii.
367 # DST was observed for one day in 1933;
368 # standard time was changed by half an hour in 1947;
369 # it's always standard as of 1986.
372 # Shanks says the 1933 experiment lasted for three weeks. Go with Shanks.
374 Zone Pacific/Honolulu -10:31:26 - LMT 1900 Jan 1 12:00
375 -10:30 - HST 1933 Apr 30 2:00
376 -10:30 1:00 HDT 1933 May 21 2:00
377 -10:30 US H%sT 1947 Jun 8 2:00
380 # Now we turn to US areas that have diverged from the consensus since 1970.
382 # Arizona mostly uses MST.
384 # From Paul Eggert (2002-10-20):
386 # The information in the rest of this paragraph is derived from the
387 # <a href="http://www.dlapr.lib.az.us/links/daylight.htm">
388 # Daylight Saving Time web page (2002-01-23)</a> maintained by the
389 # Arizona State Library, Archives and Public Records.
390 # Between 1944-01-01 and 1944-04-01 the State of Arizona used standard
391 # time, but by federal law railroads, airlines, bus lines, military
392 # personnel, and some engaged in interstate commerce continued to
393 # observe war (i.e., daylight saving) time. The 1944-03-17 Phoenix
394 # Gazette says that was the date the law changed, and that 04-01 was
395 # the date the state's clocks would change. In 1945 the State of
396 # Arizona used standard time all year, again with exceptions only as
397 # mandated by federal law. Arizona observed DST in 1967, but Arizona
398 # Laws 1968, ch. 183 (effective 1968-03-21) repealed DST.
400 # Shanks says the 1944 experiment came to an end on 1944-03-17.
401 # Go with the Arizona State Library instead.
403 Zone America/Phoenix -7:28:18 - LMT 1883 Nov 18 12:00
404 -7:00 US M%sT 1944 Jan 1 00:01
405 -7:00 - MST 1944 Apr 1 00:01
406 -7:00 US M%sT 1944 Oct 1 00:01
408 -7:00 US M%sT 1968 Mar 21
410 # From Arthur David Olson (1988-02-13):
411 # A writer from the Inter Tribal Council of Arizona, Inc.,
412 # notes in private correspondence dated 1987-12-28 that "Presently, only the
413 # Navajo Nation participates in the Daylight Saving Time policy, due to its
414 # large size and location in three states." (The "only" means that other
415 # tribal nations don't use DST.)
417 Link America/Denver America/Shiprock
419 # Southern Idaho (Ada, Adams, Bannock, Bear Lake, Bingham, Blaine,
420 # Boise, Bonneville, Butte, Camas, Canyon, Caribou, Cassia, Clark,
421 # Custer, Elmore, Franklin, Fremont, Gem, Gooding, Jefferson, Jerome,
422 # Lemhi, Lincoln, Madison, Minidoka, Oneida, Owyhee, Payette, Power,
423 # Teton, Twin Falls, Valley, Washington counties) and eastern Oregon
424 # switched four weeks late in 1974.
426 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
427 Zone America/Boise -7:44:49 - LMT 1883 Nov 18 12:00
428 -8:00 US P%sT 1923 May 13 2:00
430 -7:00 - MST 1974 Feb 3 2:00
435 # For a map of Indiana's time zone regions, see:
436 # <a href="http://www.mccsc.edu/time.html">
437 # What time is it in Indiana?
440 # From Paul Eggert (1995-12-19):
441 # Indiana generally observes either EST all year, or CST/CDT,
442 # but areas near Cincinnati and Louisville use those cities' timekeeping
443 # and in 1969 and 1970 the whole state observed daylight time;
444 # and there are other exceptions as noted below.
445 # Shanks partitions Indiana into 345 regions, each with its own time history,
446 # and writes ``Even newspaper reports present contradictory information.''
447 # Fortunately, most of the complexity occurred before our cutoff date of 1970.
449 # Since 1970, EST-only Indiana has been like America/Indianapolis,
450 # with exceptions noted below for Crawford, Starke, and Switzerland counties.
451 # The parts of Indiana not listed below have been like America/Chicago,
452 # America/Louisville, or America/New_York.
454 # Other than Indianapolis, the Indiana place names are so nondescript
455 # that they would be ambiguous if we left them at the `America' level.
456 # So we reluctantly put them all in a subdirectory `America/Indiana'.
458 # Most of EST-only Indiana last observed DST in 1970.
460 # From Paul Eggert (2001-03-06), following a tip by Markus Kuhn:
461 # Pam Belluck reported in the New York Times (2001-01-31) that the
462 # Indiana Legislature is considering a bill to adopt DST statewide.
463 # Her article mentioned Vevay, whose post office observes a different
464 # time zone from Danner's Hardware across the street.
466 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER
467 Rule Indianapolis 1941 only - Jun 22 2:00 1:00 D
468 Rule Indianapolis 1941 1954 - Sep lastSun 2:00 0 S
469 Rule Indianapolis 1946 1954 - Apr lastSun 2:00 1:00 D
470 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
471 Zone America/Indianapolis -5:44:38 - LMT 1883 Nov 18 12:00
473 -6:00 Indianapolis C%sT 1942
475 -6:00 Indianapolis C%sT 1955 Apr 24 2:00
476 -5:00 - EST 1957 Sep 29 2:00
477 -6:00 - CST 1958 Apr 27 2:00
481 Link America/Indianapolis America/Indiana/Indianapolis
483 # Part of Crawford County, Indiana, last observed DST in 1975,
484 # and left its clocks alone in 1974.
485 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER
486 Rule Marengo 1951 only - Apr lastSun 2:00 1:00 D
487 Rule Marengo 1951 only - Sep lastSun 2:00 0 S
488 Rule Marengo 1954 1960 - Apr lastSun 2:00 1:00 D
489 Rule Marengo 1954 1960 - Sep lastSun 2:00 0 S
490 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
491 Zone America/Indiana/Marengo -5:45:23 - LMT 1883 Nov 18 12:00
493 -6:00 Marengo C%sT 1961 Apr 30 2:00
495 -5:00 US E%sT 1974 Jan 6 2:00
496 -6:00 1:00 CDT 1974 Oct 27 2:00
500 # Starke County, Indiana
501 # From Arthur David Olson (1991-10-28):
502 # An article on page A3 of the Sunday, 1991-10-27 Washington Post
503 # notes that Starke County switched from Central time to Eastern time as of
505 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER
506 Rule Starke 1947 1961 - Apr lastSun 2:00 1:00 D
507 Rule Starke 1947 1954 - Sep lastSun 2:00 0 S
508 Rule Starke 1955 1956 - Oct lastSun 2:00 0 S
509 Rule Starke 1957 1958 - Sep lastSun 2:00 0 S
510 Rule Starke 1959 1961 - Oct lastSun 2:00 0 S
511 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
512 Zone America/Indiana/Knox -5:46:30 - LMT 1883 Nov 18 12:00
514 -6:00 Starke C%sT 1962 Apr 29 2:00
515 -5:00 - EST 1963 Oct 27 2:00
516 -6:00 US C%sT 1991 Oct 27 2:00
519 # Switzerland County, Indiana, last observed DST in 1972.
520 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
521 Zone America/Indiana/Vevay -5:40:16 - LMT 1883 Nov 18 12:00
522 -6:00 US C%sT 1954 Apr 25 2:00
527 # Part of Kentucky left its clocks alone in 1974.
528 # This also includes a part of Indiana immediately adjacent to Louisville.
529 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER
530 Rule Louisville 1921 only - May 1 2:00 1:00 D
531 Rule Louisville 1921 only - Sep 1 2:00 0 S
532 Rule Louisville 1941 1961 - Apr lastSun 2:00 1:00 D
533 Rule Louisville 1941 only - Sep lastSun 2:00 0 S
534 Rule Louisville 1946 only - Jun 2 2:00 0 S
535 Rule Louisville 1950 1955 - Sep lastSun 2:00 0 S
536 Rule Louisville 1956 1960 - Oct lastSun 2:00 0 S
537 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
538 Zone America/Louisville -5:43:02 - LMT 1883 Nov 18 12:00
540 -6:00 Louisville C%sT 1942
542 -6:00 Louisville C%sT 1961 Jul 23 2:00
544 -5:00 US E%sT 1974 Jan 6 2:00
545 -6:00 1:00 CDT 1974 Oct 27 2:00
547 Link America/Louisville America/Kentucky/Louisville
549 # Wayne, Clinton, and Russell Counties, Kentucky
552 # <a href="http://www.lake-cumberland.com/life/archive/news990129time.shtml">
553 # Lake Cumberland LIFE
554 # </a> (1999-01-29) via WKYM-101.7:
555 # Clinton County has joined Wayne County in asking the DoT to change from
556 # the Central to the Eastern time zone.... The Wayne County government made
557 # the same request in December. And while Russell County officials have not
558 # taken action, the majority of respondents to a poll conducted there in
559 # August indicated they would like to change to "fast time" also.
560 # The three Lake Cumberland counties are the farthest east of any U.S.
561 # location in the Central time zone.
563 # From Rich Wales (2000-08-29):
564 # After prolonged debate, and despite continuing deep differences of opinion,
565 # Wayne County (central Kentucky) is switching from Central (-0600) to Eastern
566 # (-0500) time. They won't "fall back" this year. See Sara Shipley,
567 # The difference an hour makes, Nando Times (2000-08-29 15:33 -0400).
569 # From Paul Eggert (2001-07-16):
570 # The final rule was published in the
571 # <a href="http://frwebgate.access.gpo.gov/cgi-bin/getdoc.cgi?dbname=2000_register&docid=fr17au00-22">
572 # Federal Register 65, 160 (2000-08-17), page 50154-50158.
575 Zone America/Kentucky/Monticello -5:39:24 - LMT 1883 Nov 18 12:00
578 -6:00 US C%sT 2000 Oct 29 2:00
582 # From Rives McDow (2000-08-30):
583 # Here ... are all the changes in the US since 1985.
584 # Kearny County, KS (put all of county on central;
585 # previously split between MST and CST) ... 1990-10
586 # Starke County, IN (from CST to EST) ... 1991-10
587 # Oliver County, ND (from MST to CST) ... 1992-10
588 # West Wendover, NV (from PST TO MST) ... 1999-10
589 # Wayne County, KY (from CST to EST) ... 2000-10
591 # From Paul Eggert (2001-07-17):
592 # We don't know where the line used to be within Kearny County, KS,
593 # so omit that change for now.
594 # See America/Indiana/Knox for the Starke County, IN change.
595 # See America/North_Dakota/Center for the Oliver County, ND change.
596 # West Wendover, NV officially switched from Pacific to mountain time on
597 # 1999-10-31. See the
598 # <a href="http://frwebgate.access.gpo.gov/cgi-bin/getdoc.cgi?dbname=1999_register&docid=fr21oc99-15">
599 # Federal Register 64, 203 (1999-10-21), page 56705-56707.
601 # However, the Federal Register says that West Wendover already operated
602 # on mountain time, and the rule merely made this official;
603 # hence a separate tz entry is not needed.
607 # From Bob Devine (1988-01-28):
608 # Michigan didn't observe DST from 1968 to 1973.
610 # From Paul Eggert (1999-03-31):
611 # Shanks writes that Michigan started using standard time on 1885-09-18,
612 # but Howse writes (pp 124-125, referring to Popular Astronomy, 1901-01)
615 # local time until 1900 when the City Council decreed that clocks should
616 # be put back twenty-eight minutes to Central Standard Time. Half the
617 # city obeyed, half refused. After considerable debate, the decision
618 # was rescinded and the city reverted to Sun time. A derisive offer to
619 # erect a sundial in front of the city hall was referred to the
620 # Committee on Sewers. Then, in 1905, Central time was adopted
623 # This story is too entertaining to be false, so go with Howse over Shanks.
625 # From Paul Eggert (2001-03-06):
626 # Garland (1927) writes ``Cleveland and Detroit advanced their clocks
627 # one hour in 1914.'' This change is not in Shanks. We have no more
628 # info, so omit this for now.
630 # Most of Michigan observed DST from 1973 on, but was a bit late in 1975.
631 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER
632 Rule Detroit 1948 only - Apr lastSun 2:00 1:00 D
633 Rule Detroit 1948 only - Sep lastSun 2:00 0 S
634 Rule Detroit 1967 only - Jun 14 2:00 1:00 D
635 Rule Detroit 1967 only - Oct lastSun 2:00 0 S
636 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
637 Zone America/Detroit -5:32:11 - LMT 1905
638 -6:00 - CST 1915 May 15 2:00
641 -5:00 Detroit E%sT 1973
643 -5:00 - EST 1975 Apr 27 2:00
646 # The Michigan border with Wisconsin switched from EST to CST/CDT in 1973.
647 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER
648 Rule Menominee 1946 only - Apr lastSun 2:00 1:00 D
649 Rule Menominee 1946 only - Sep lastSun 2:00 0 S
650 Rule Menominee 1966 only - Apr lastSun 2:00 1:00 D
651 Rule Menominee 1966 only - Oct lastSun 2:00 0 S
652 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
653 Zone America/Menominee -5:50:27 - LMT 1885 Sep 18 12:00
655 -6:00 Menominee C%sT 1969 Apr 27 2:00
656 -5:00 - EST 1973 Apr 29 2:00
660 # administered by the US Fish and Wildlife Service
661 # claimed by US under the provisions of the 1856 Guano Islands Act
662 # also claimed by Haiti
663 # occupied 1857/1900 by the Navassa Phosphate Co
664 # US lighthouse 1917/1996-09
665 # currently uninhabited
666 # see Mark Fineman, ``An Isle Rich in Guano and Discord'',
667 # _Los Angeles Times_ (1998-11-10), A1, A10; it cites
668 # Jimmy Skaggs, _The Great Guano Rush_ (1994).
670 # Old names, for S5 users
672 # Link LINK-FROM LINK-TO
673 Link America/New_York EST5EDT
674 Link America/Chicago CST6CDT
675 Link America/Denver MST7MDT
676 Link America/Los_Angeles PST8PDT
677 Link America/Indianapolis EST
678 Link America/Phoenix MST
679 Link Pacific/Honolulu HST
681 ################################################################################
684 # From Paul Eggert <eggert@twinsun.com> (1999-10-29):
685 # A good source for time zone historical data outside the US is
686 # Thomas G. Shanks, The International Atlas (5th edition),
687 # San Diego: ACS Publications, Inc. (1999).
689 # Gwillim Law writes that a good source
690 # for recent time zone data is the International Air Transport
691 # Association's Standard Schedules Information Manual (IATA SSIM),
692 # published semiannually. Law sent in several helpful summaries
693 # of the IATA's data after 1990.
695 # Except where otherwise noted, Shanks is the source for entries through 1990,
696 # and IATA SSIM is the source for entries after 1990.
698 # Other sources occasionally used include:
700 # Edward W. Whitman, World Time Differences,
701 # Whitman Publishing Co, 2 Niagara Av, Ealing, London (undated),
702 # which I found in the UCLA library.
704 # <a href="http://www.pettswoodvillage.co.uk/Daylight_Savings_William_Willett.pdf">
705 # William Willett, The Waste of Daylight, 19th edition
708 # See the `europe' file for Greenland.
712 # From Alain LaBont<e'> <ALB@immedia.ca> (1994-11-14):
713 # I post here the time zone abbreviations standardized in Canada
714 # for both English and French in the CAN/CSA-Z234.4-89 standard....
716 # UTC Standard time Daylight savings time
717 # offset French English French English
728 # HN: Heure Normale ST: Standard Time
729 # HA: Heure Avanc<e'>e DT: Daylight saving Time
731 # A: de l'Atlantique Atlantic
732 # C: du Centre Central
733 # E: de l'Est Eastern
736 # P: du Pacifique Pacific
741 # From Paul Eggert <eggert@twinsun.com> (1994-11-22):
742 # Alas, this sort of thing must be handled by localization software.
744 # Unless otherwise specified, the data for Canada are all from Shanks.
746 # From Paul Eggert (2000-10-02):
747 # H. David Matthews and Mary Vincent's map
748 # <a href="http://www.canadiangeographic.ca/SO98/geomap.htm">
749 # "It's about TIME", _Canadian Geographic_ (September-October 1998)
750 # </a> contains detailed boundaries for regions observing nonstandard
751 # time and daylight saving time arrangements in Canada circa 1998.
753 # INMS, the Institute for National Measurement Standards in Ottawa, has
754 # <a href="http://www.nrc.ca/inms/time/tze.html">
755 # information about standard and daylight saving time zones in Canada.
756 # </a> (updated periodically).
757 # Its unofficial information is often taken from Matthews and Vincent.
759 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
760 Rule Canada 1918 only - Apr 14 2:00 1:00 D
761 Rule Canada 1918 only - Oct 31 2:00 0 S
762 Rule Canada 1942 only - Feb 9 2:00 1:00 W # War
763 Rule Canada 1945 only - Aug 14 23:00u 1:00 P # Peace
764 Rule Canada 1945 only - Sep 30 2:00 0 S
765 Rule Canada 1974 1986 - Apr lastSun 2:00 1:00 D
766 Rule Canada 1974 max - Oct lastSun 2:00 0 S
767 Rule Canada 1987 max - Apr Sun>=1 2:00 1:00 D
770 # Newfoundland (and far southeast Labrador)
772 # From Paul Eggert (2000-10-02):
773 # Matthews and Vincent (1998) write that Labrador should use NST/NDT,
774 # but the only part of Labrador that follows the rules is the
775 # southeast corner, including Port Hope Simpson and Mary's Harbour,
776 # but excluding, say, Black Tickle.
778 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
779 Rule StJohns 1917 only - Apr 8 2:00 1:00 D
780 Rule StJohns 1917 only - Sep 17 2:00 0 S
781 # Whitman gives 1919 Apr 5 and 1920 Apr 5; go with Shanks.
782 Rule StJohns 1919 only - May 5 23:00 1:00 D
783 Rule StJohns 1919 only - Aug 12 23:00 0 S
784 # For 1931-1935 Whitman gives Apr same date; go with Shanks.
785 Rule StJohns 1920 1935 - May Sun>=1 23:00 1:00 D
786 Rule StJohns 1920 1935 - Oct lastSun 23:00 0 S
787 # For 1936-1941 Whitman gives May Sun>=8 and Oct Sun>=1; go with Shanks.
788 Rule StJohns 1936 1941 - May Mon>=9 0:00 1:00 D
789 Rule StJohns 1936 1941 - Oct Mon>=2 0:00 0 S
790 # Whitman gives the following transitions:
791 # 1942 03-01/12-31, 1943 05-30/09-05, 1944 07-10/09-02, 1945 01-01/10-07
792 # but go with Shanks and assume they used Canadian rules.
793 # For 1946-9 Whitman gives May 5,4,9,1 - Oct 1,5,3,2, and for 1950 he gives
794 # Apr 30 - Sep 24; go with Shanks.
795 Rule StJohns 1946 1950 - May Sun>=8 2:00 1:00 D
796 Rule StJohns 1946 1950 - Oct Sun>=2 2:00 0 S
797 Rule StJohns 1951 1986 - Apr lastSun 2:00 1:00 D
798 Rule StJohns 1951 1959 - Sep lastSun 2:00 0 S
799 Rule StJohns 1960 1986 - Oct lastSun 2:00 0 S
800 # From Paul Eggert (2000-10-02):
801 # INMS (2000-09-12) says that, since 1988 at least, Newfoundland switches
802 # at 00:01 local time. For now, assume it started in 1987.
803 Rule StJohns 1987 only - Apr Sun>=1 0:01 1:00 D
804 Rule StJohns 1987 max - Oct lastSun 0:01 0 S
805 Rule StJohns 1988 only - Apr Sun>=1 0:01 2:00 DD
806 Rule StJohns 1989 max - Apr Sun>=1 0:01 1:00 D
807 # St John's has an apostrophe, but Posix file names can't have apostrophes.
808 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
809 Zone America/St_Johns -3:30:52 - LMT 1884
810 -3:30:52 StJohns N%sT 1918
811 -3:30:52 Canada N%sT 1919
812 -3:30:52 StJohns N%sT 1935 Mar 30
813 -3:30 StJohns N%sT 1942 May 11
814 -3:30 Canada N%sT 1946
817 # most of east Labrador
819 # The name `Happy Valley-Goose Bay' is too long; use `Goose Bay'.
820 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
821 Zone America/Goose_Bay -4:01:40 - LMT 1884 # Happy Valley-Goose Bay
823 -3:30:52 Canada N%sT 1919
824 -3:30:52 - NST 1935 Mar 30
826 -3:30 StJohns N%sT 1942 May 11
827 -3:30 Canada N%sT 1946
828 -3:30 StJohns N%sT 1966 Mar 15 2:00
832 # west Labrador, New Brunswick, Nova Scotia, Prince Edward I
834 # From Paul Eggert (1996-06-12):
835 # Shanks writes that since 1970 most of this region has been like Halifax.
836 # Many locales did not observe peacetime DST until 1972;
837 # Glace Bay, NS is the largest that we know of.
838 # Shanks also writes that Liverpool, NS was the only town in Canada to observe
839 # DST in 1971 but not 1970; for now we'll assume this is a typo.
841 # From Paul Eggert (2000-10-02):
842 # INMS (2000-09-12) says that, since 1988 at least, New Brunswick switches
843 # at 00:01 local time. FIXME: verify and create a new Zone for this.
846 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
847 Rule Halifax 1916 only - Apr 1 0:00 1:00 D
848 Rule Halifax 1916 only - Oct 1 0:00 0 S
849 Rule Halifax 1920 only - May 9 0:00 1:00 D
850 Rule Halifax 1920 only - Aug 29 0:00 0 S
851 Rule Halifax 1921 only - May 6 0:00 1:00 D
852 Rule Halifax 1921 1922 - Sep 5 0:00 0 S
853 Rule Halifax 1922 only - Apr 30 0:00 1:00 D
854 Rule Halifax 1923 1925 - May Sun>=1 0:00 1:00 D
855 Rule Halifax 1923 only - Sep 4 0:00 0 S
856 Rule Halifax 1924 only - Sep 15 0:00 0 S
857 Rule Halifax 1925 only - Sep 28 0:00 0 S
858 Rule Halifax 1926 only - May 16 0:00 1:00 D
859 Rule Halifax 1926 only - Sep 13 0:00 0 S
860 Rule Halifax 1927 only - May 1 0:00 1:00 D
861 Rule Halifax 1927 only - Sep 26 0:00 0 S
862 Rule Halifax 1928 1931 - May Sun>=8 0:00 1:00 D
863 Rule Halifax 1928 only - Sep 9 0:00 0 S
864 Rule Halifax 1929 only - Sep 3 0:00 0 S
865 Rule Halifax 1930 only - Sep 15 0:00 0 S
866 Rule Halifax 1931 1932 - Sep Mon>=24 0:00 0 S
867 Rule Halifax 1932 only - May 1 0:00 1:00 D
868 Rule Halifax 1933 only - Apr 30 0:00 1:00 D
869 Rule Halifax 1933 only - Oct 2 0:00 0 S
870 Rule Halifax 1934 only - May 20 0:00 1:00 D
871 Rule Halifax 1934 only - Sep 16 0:00 0 S
872 Rule Halifax 1935 only - Jun 2 0:00 1:00 D
873 Rule Halifax 1935 only - Sep 30 0:00 0 S
874 Rule Halifax 1936 only - Jun 1 0:00 1:00 D
875 Rule Halifax 1936 only - Sep 14 0:00 0 S
876 Rule Halifax 1937 1938 - May Sun>=1 0:00 1:00 D
877 Rule Halifax 1937 1941 - Sep Mon>=24 0:00 0 S
878 Rule Halifax 1939 only - May 28 0:00 1:00 D
879 Rule Halifax 1940 1941 - May Sun>=1 0:00 1:00 D
880 Rule Halifax 1946 1949 - Sep lastSun 2:00 0 S
881 Rule Halifax 1946 1949 - Apr lastSun 2:00 1:00 D
882 Rule Halifax 1951 1954 - Sep lastSun 2:00 0 S
883 Rule Halifax 1951 1954 - Apr lastSun 2:00 1:00 D
884 Rule Halifax 1956 1959 - Sep lastSun 2:00 0 S
885 Rule Halifax 1956 1959 - Apr lastSun 2:00 1:00 D
886 Rule Halifax 1962 1973 - Apr lastSun 2:00 1:00 D
887 Rule Halifax 1962 1973 - Oct lastSun 2:00 0 S
888 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
889 Zone America/Halifax -4:14:24 - LMT 1902 Jun 15
890 -4:00 Halifax A%sT 1918
891 -4:00 Canada A%sT 1919
892 -4:00 Halifax A%sT 1942 Feb 9 2:00s
893 -4:00 Canada A%sT 1946
894 -4:00 Halifax A%sT 1974
896 Zone America/Glace_Bay -3:59:48 - LMT 1902 Jun 15
897 -4:00 Canada A%sT 1953
898 -4:00 Halifax A%sT 1954
900 -4:00 Halifax A%sT 1974
906 # From Paul Eggert (1996-06-12):
907 # Shanks writes that since 1970 most of Ontario has been like Toronto,
908 # and most of Quebec has been like Montreal.
909 # Thunder Bay skipped DST in 1973.
910 # Many smaller locales did not observe peacetime DST until 1974;
911 # Nipigon (EST) and Rainy River (CST) are the largest that we know of.
912 # Far west Ontario is like Winnipeg; far east Quebec is like Halifax.
914 # From Mark Brader (2003-07-26):
915 # [According to the Toronto Star] Orillia, Ontario, adopted DST
916 # effective Saturday, 1912-06-22, 22:00; the article mentions that
917 # Port Arthur (now part of Thunder Bay, Ontario) as well as Moose Jaw
918 # have already done so. In Orillia DST was to run until Saturday,
919 # 1912-08-31 (no time mentioned), but it was met with considerable
920 # hostility from certain segments of the public, and was revoked after
921 # only two weeks -- I copied it as Saturday, 1912-07-07, 22:00, but
922 # presumably that should be -07-06. (1912-06-19, -07-12; also letters
925 # Kenora, Ontario, was to abandon DST on 1914-06-01 (-05-21).
927 # From Paul Eggert (1997-10-17):
928 # Mark Brader writes that an article in the 1997-10-14 Toronto Star
929 # says that Atikokan, Ontario currently does not observe DST,
930 # but will vote on 11-10 whether to use EST/EDT.
931 # He also writes that the
932 # <a href="http://www.gov.on.ca/MBS/english/publications/statregs/conttext.html">
933 # Ontario Time Act (1990, Chapter T.9)
935 # says that Ontario east of 90W uses EST/EDT, and west of 90W uses CST/CDT.
936 # Officially Atikokan is therefore on CST/CDT, and most likely this report
937 # concerns a non-official time observed as a matter of local practice.
938 # For what it's worth, Shanks says that Atikokan has agreed with
939 # Rainy River ever since standard time was introduced.
941 # From Paul Eggert (2000-10-02):
942 # Matthews and Vincent (1998) write that Atikokan, Pickle Lake, and
943 # New Osnaburgh observe CST all year, that Big Trout Lake observes
944 # CST/CDT, and that Upsala and Shebandowan observe EST/EDT, all in
945 # violation of the official Ontario rules.
946 # They also write that Quebec east of the -63 meridian is supposed to
947 # observe AST, but residents as far east as Natashquan use EST/EDT,
948 # and residents east of Natashquan use AST.
949 # We probably need Zones for far east Quebec and for Atikokan,
950 # but we don't know when their practices started.
952 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
953 Rule Mont 1917 only - Mar 25 2:00 1:00 D
954 Rule Mont 1917 only - Apr 24 0:00 0 S
955 Rule Mont 1919 only - Mar 31 2:30 1:00 D
956 Rule Mont 1919 only - Oct 25 2:30 0 S
957 Rule Mont 1920 only - May 2 2:30 1:00 D
958 Rule Mont 1920 1922 - Oct Sun>=1 2:30 0 S
959 Rule Mont 1921 only - May 1 2:00 1:00 D
960 Rule Mont 1922 only - Apr 30 2:00 1:00 D
961 Rule Mont 1924 only - May 17 2:00 1:00 D
962 Rule Mont 1924 1926 - Sep lastSun 2:30 0 S
963 Rule Mont 1925 1926 - May Sun>=1 2:00 1:00 D
964 # The 1927-to-1937 rules can be expressed more simply as
965 # Rule Mont 1927 1937 - Apr lastSat 24:00 1:00 D
966 # Rule Mont 1927 1937 - Sep lastSat 24:00 0 S
967 # The rules below avoid use of 24:00
968 # (which pre-1998 versions of zic cannot handle).
969 Rule Mont 1927 only - May 1 0:00 1:00 D
970 Rule Mont 1927 1932 - Sep lastSun 0:00 0 S
971 Rule Mont 1928 1931 - Apr lastSun 0:00 1:00 D
972 Rule Mont 1932 only - May 1 0:00 1:00 D
973 Rule Mont 1933 1940 - Apr lastSun 0:00 1:00 D
974 Rule Mont 1933 only - Oct 1 0:00 0 S
975 Rule Mont 1934 1939 - Sep lastSun 0:00 0 S
976 Rule Mont 1946 1973 - Apr lastSun 2:00 1:00 D
977 Rule Mont 1945 1948 - Sep lastSun 2:00 0 S
978 Rule Mont 1949 1950 - Oct lastSun 2:00 0 S
979 Rule Mont 1951 1956 - Sep lastSun 2:00 0 S
980 Rule Mont 1957 1973 - Oct lastSun 2:00 0 S
982 Rule Toronto 1919 only - Mar 30 23:30 1:00 D
983 Rule Toronto 1919 only - Oct 26 0:00 0 S
984 Rule Toronto 1920 only - May 2 2:00 1:00 D
985 Rule Toronto 1920 only - Sep 26 0:00 0 S
986 Rule Toronto 1921 only - May 15 2:00 1:00 D
987 Rule Toronto 1921 only - Sep 15 2:00 0 S
988 Rule Toronto 1922 1923 - May Sun>=8 2:00 1:00 D
989 # Shanks says 1923-09-19; assume it's a typo and that "-16" was meant.
990 Rule Toronto 1922 1926 - Sep Sun>=15 2:00 0 S
991 Rule Toronto 1924 1927 - May Sun>=1 2:00 1:00 D
992 # The 1927-to-1939 rules can be expressed more simply as
993 # Rule Toronto 1927 1937 - Sep Sun>=25 2:00 0 S
994 # Rule Toronto 1928 1937 - Apr Sun>=25 2:00 1:00 D
995 # Rule Toronto 1938 1940 - Apr lastSun 2:00 1:00 D
996 # Rule Toronto 1938 1939 - Sep lastSun 2:00 0 S
997 # The rules below avoid use of Sun>=25
998 # (which pre-2004 versions of zic cannot handle).
999 Rule Toronto 1927 1932 - Sep lastSun 2:00 0 S
1000 Rule Toronto 1928 1931 - Apr lastSun 2:00 1:00 D
1001 Rule Toronto 1932 only - May 1 2:00 1:00 D
1002 Rule Toronto 1933 1940 - Apr lastSun 2:00 1:00 D
1003 Rule Toronto 1933 only - Oct 1 2:00 0 S
1004 Rule Toronto 1934 1939 - Sep lastSun 2:00 0 S
1005 Rule Toronto 1945 1946 - Sep lastSun 2:00 0 S
1006 Rule Toronto 1946 only - Apr lastSun 2:00 1:00 D
1007 Rule Toronto 1947 1949 - Apr lastSun 0:00 1:00 D
1008 Rule Toronto 1947 1948 - Sep lastSun 0:00 0 S
1009 Rule Toronto 1949 only - Nov lastSun 0:00 0 S
1010 Rule Toronto 1950 1973 - Apr lastSun 2:00 1:00 D
1011 Rule Toronto 1950 only - Nov lastSun 2:00 0 S
1012 Rule Toronto 1951 1956 - Sep lastSun 2:00 0 S
1013 # Shanks says Toronto ended DST a week early in 1971, namely on 1971-10-24,
1014 # but Mark Brader wrote (2003-05-31) that he checked the 1971-10-30 issue
1015 # of the Toronto Star, and it said that DST ended 1971-10-31 as usual.
1016 Rule Toronto 1957 1973 - Oct lastSun 2:00 0 S
1018 # From Paul Eggert (2003-07-27):
1019 # Willett (1914-03) writes (p. 17) "In the Cities of Fort William, and
1020 # Port Arthur, Ontario, the principle of the Bill has been in
1021 # operation for the past three years, and in the City of Moose Jaw,
1022 # Saskatchewan, for one year."
1024 # From David Bryan via Tory Tronrud, Director/Curator,
1025 # Thunder Bay Museum (2003-11-12):
1026 # There is some suggestion, however, that, by-law or not, daylight
1027 # savings time was being practiced in Fort William and Port Arthur
1028 # before 1909.... [I]n 1910, the line between the Eastern and Central
1029 # Time Zones was permanently moved about two hundred miles west to
1030 # include the Thunder Bay area.... When Canada adopted daylight
1031 # savings time in 1916, Fort William and Port Arthur, having done so
1032 # already, did not change their clocks.... During the Second World
1033 # War,... [t]he cities agreed to implement DST during the summer
1034 # months for the remainder of the war years.
1036 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1037 Zone America/Montreal -4:54:16 - LMT 1884
1038 -5:00 Mont E%sT 1918
1039 -5:00 Canada E%sT 1919
1040 -5:00 Mont E%sT 1942 Feb 9 2:00s
1041 -5:00 Canada E%sT 1946
1042 -5:00 Mont E%sT 1974
1044 Zone America/Toronto -5:17:32 - LMT 1895
1045 -5:00 Canada E%sT 1919
1046 -5:00 Toronto E%sT 1942 Feb 9 2:00s
1047 -5:00 Canada E%sT 1946
1048 -5:00 Toronto E%sT 1974
1050 Zone America/Thunder_Bay -5:57:00 - LMT 1895
1053 -5:00 Canada E%sT 1970
1054 -5:00 Mont E%sT 1973
1057 Zone America/Nipigon -5:53:04 - LMT 1895
1058 -5:00 Canada E%sT 1940 Sep 29
1059 -5:00 1:00 EDT 1942 Feb 9 2:00s
1061 Zone America/Rainy_River -6:17:56 - LMT 1895
1062 -6:00 Canada C%sT 1940 Sep 29
1063 -6:00 1:00 CDT 1942 Feb 9 2:00s
1069 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
1070 Rule Winn 1916 only - Apr 23 0:00 1:00 D
1071 Rule Winn 1916 only - Sep 17 0:00 0 S
1072 Rule Winn 1918 only - Apr 14 2:00 1:00 D
1073 Rule Winn 1918 only - Oct 31 2:00 0 S
1074 Rule Winn 1937 only - May 16 2:00 1:00 D
1075 Rule Winn 1937 only - Sep 26 2:00 0 S
1076 Rule Winn 1942 only - Feb 9 2:00 1:00 W # War
1077 Rule Winn 1945 only - Aug 14 23:00u 1:00 P # Peace
1078 Rule Winn 1945 only - Sep lastSun 2:00 0 S
1079 Rule Winn 1946 only - May 12 2:00 1:00 D
1080 Rule Winn 1946 only - Oct 13 2:00 0 S
1081 Rule Winn 1947 1949 - Apr lastSun 2:00 1:00 D
1082 Rule Winn 1947 1949 - Sep lastSun 2:00 0 S
1083 Rule Winn 1950 only - May 1 2:00 1:00 D
1084 Rule Winn 1950 only - Sep 30 2:00 0 S
1085 Rule Winn 1951 1960 - Apr lastSun 2:00 1:00 D
1086 Rule Winn 1951 1958 - Sep lastSun 2:00 0 S
1087 Rule Winn 1959 only - Oct lastSun 2:00 0 S
1088 Rule Winn 1960 only - Sep lastSun 2:00 0 S
1089 Rule Winn 1963 only - Apr lastSun 2:00 1:00 D
1090 Rule Winn 1963 only - Sep 22 2:00 0 S
1091 Rule Winn 1966 1986 - Apr lastSun 2:00 1:00 D
1092 Rule Winn 1966 1986 - Oct lastSun 2:00 0 S
1093 Rule Winn 1987 max - Apr Sun>=1 2:00 1:00 D
1094 # From Paul Eggert (2000-10-02):
1095 # INMS (2000-09-12) says that, since 1988 at least, Manitoba switches from
1096 # DST at 03:00 local time. For now, assume it started in 1987.
1097 Rule Winn 1987 max - Oct lastSun 2:00s 0 S
1098 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1099 Zone America/Winnipeg -6:28:36 - LMT 1887 Jul 16
1105 # From Mark Brader (2003-07-26):
1106 # The first actual adoption of DST in Canada was at the municipal
1107 # level. As the [Toronto] Star put it (1912-06-07), "While people
1108 # elsewhere have long been talking of legislation to save daylight,
1109 # the city of Moose Jaw [Saskatchewan] has acted on its own hook."
1110 # DST in Moose Jaw began on Saturday, 1912-06-01 (no time mentioned:
1111 # presumably late evening, as below), and would run until "the end of
1112 # the summer". The discrepancy between municipal time and railroad
1115 # From Paul Eggert (2003-07-27):
1116 # Willett (1914-03) notes that DST "has been in operation ... in the
1117 # City of Moose Jaw, Saskatchewan, for one year."
1119 # From Paul Eggert (2000-10-02):
1120 # Shanks writes that since 1970 most of this region has been like Regina.
1121 # Some western towns (e.g. Swift Current) switched from MST/MDT to CST in 1972.
1122 # Other western towns (e.g. Lloydminster) are like Edmonton.
1123 # Matthews and Vincent (1998) write that Denare Beach and Creighton
1124 # are like Winnipeg, in violation of Saskatchewan law.
1126 # From W. Jones <jones@skdad.usask.ca> (1992-11-06):
1127 # The. . .below is based on information I got from our law library, the
1128 # provincial archives, and the provincial Community Services department.
1129 # A precise history would require digging through newspaper archives, and
1130 # since you didn't say what you wanted, I didn't bother.
1132 # Saskatchewan is split by a time zone meridian (105W) and over the years
1133 # the boundary became pretty ragged as communities near it reevaluated
1134 # their affiliations in one direction or the other. In 1965 a provincial
1135 # referendum favoured legislating common time practices.
1137 # On 15 April 1966 the Time Act (c. T-14, Revised Statutes of
1138 # Saskatchewan 1978) was proclaimed, and established that the eastern
1139 # part of Saskatchewan would use CST year round, that districts in
1140 # northwest Saskatchewan would by default follow CST but could opt to
1141 # follow Mountain Time rules (thus 1 hour difference in the winter and
1142 # zero in the summer), and that districts in southwest Saskatchewan would
1143 # by default follow MT but could opt to follow CST.
1145 # It took a few years for the dust to settle (I know one story of a town
1146 # on one time zone having its school in another, such that a mom had to
1147 # serve her family lunch in two shifts), but presently it seems that only
1148 # a few towns on the border with Alberta (e.g. Lloydminster) follow MT
1149 # rules any more; all other districts appear to have used CST year round
1150 # since sometime in the 1960s.
1152 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
1153 Rule Regina 1918 only - Apr 14 2:00 1:00 D
1154 Rule Regina 1918 only - Oct 31 2:00 0 S
1155 Rule Regina 1930 1934 - May Sun>=1 0:00 1:00 D
1156 Rule Regina 1930 1934 - Oct Sun>=1 0:00 0 S
1157 Rule Regina 1937 1941 - Apr Sun>=8 0:00 1:00 D
1158 Rule Regina 1937 only - Oct Sun>=8 0:00 0 S
1159 Rule Regina 1938 only - Oct Sun>=1 0:00 0 S
1160 Rule Regina 1939 1941 - Oct Sun>=8 0:00 0 S
1161 Rule Regina 1942 only - Feb 9 2:00 1:00 W # War
1162 Rule Regina 1945 only - Aug 14 23:00u 1:00 P # Peace
1163 Rule Regina 1945 only - Sep lastSun 2:00 0 S
1164 Rule Regina 1946 only - Apr Sun>=8 2:00 1:00 D
1165 Rule Regina 1946 only - Oct Sun>=8 2:00 0 S
1166 Rule Regina 1947 1957 - Apr lastSun 2:00 1:00 D
1167 Rule Regina 1947 1957 - Sep lastSun 2:00 0 S
1168 Rule Regina 1959 only - Apr lastSun 2:00 1:00 D
1169 Rule Regina 1959 only - Oct lastSun 2:00 0 S
1171 Rule Swift 1957 only - Apr lastSun 2:00 1:00 D
1172 Rule Swift 1957 only - Oct lastSun 2:00 0 S
1173 Rule Swift 1959 1961 - Apr lastSun 2:00 1:00 D
1174 Rule Swift 1959 only - Oct lastSun 2:00 0 S
1175 Rule Swift 1960 1961 - Sep lastSun 2:00 0 S
1176 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1177 Zone America/Regina -6:58:36 - LMT 1905 Sep
1178 -7:00 Regina M%sT 1960 Apr lastSun 2:00
1180 Zone America/Swift_Current -7:11:20 - LMT 1905 Sep
1181 -7:00 Canada M%sT 1946 Apr lastSun 2:00
1182 -7:00 Regina M%sT 1950
1183 -7:00 Swift M%sT 1972 Apr lastSun 2:00
1189 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
1190 Rule Edm 1918 1919 - Apr Sun>=8 2:00 1:00 D
1191 Rule Edm 1918 only - Oct 31 2:00 0 S
1192 Rule Edm 1919 only - May 27 2:00 0 S
1193 Rule Edm 1920 1923 - Apr lastSun 2:00 1:00 D
1194 Rule Edm 1920 only - Oct lastSun 2:00 0 S
1195 Rule Edm 1921 1923 - Sep lastSun 2:00 0 S
1196 Rule Edm 1942 only - Feb 9 2:00 1:00 W # War
1197 Rule Edm 1945 only - Aug 14 23:00u 1:00 P # Peace
1198 Rule Edm 1945 only - Sep lastSun 2:00 0 S
1199 Rule Edm 1947 only - Apr lastSun 2:00 1:00 D
1200 Rule Edm 1947 only - Sep lastSun 2:00 0 S
1201 Rule Edm 1967 only - Apr lastSun 2:00 1:00 D
1202 Rule Edm 1967 only - Oct lastSun 2:00 0 S
1203 Rule Edm 1969 only - Apr lastSun 2:00 1:00 D
1204 Rule Edm 1969 only - Oct lastSun 2:00 0 S
1205 Rule Edm 1972 1986 - Apr lastSun 2:00 1:00 D
1206 Rule Edm 1972 max - Oct lastSun 2:00 0 S
1207 Rule Edm 1987 max - Apr Sun>=1 2:00 1:00 D
1208 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1209 Zone America/Edmonton -7:33:52 - LMT 1906 Sep
1215 # From Paul Eggert (2000-10-02):
1216 # Shanks writes that since 1970 most of this region has been like Vancouver.
1217 # Dawson Creek uses MST. Much of east BC is like Edmonton.
1218 # Matthews and Vincent (1998) write that Creston is like Dawson Creek.
1220 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
1221 Rule Vanc 1918 only - Apr 14 2:00 1:00 D
1222 Rule Vanc 1918 only - Oct 31 2:00 0 S
1223 Rule Vanc 1942 only - Feb 9 2:00 1:00 W # War
1224 Rule Vanc 1945 only - Aug 14 23:00u 1:00 P # Peace
1225 Rule Vanc 1945 only - Sep 30 2:00 0 S
1226 Rule Vanc 1946 1986 - Apr lastSun 2:00 1:00 D
1227 Rule Vanc 1946 only - Oct 13 2:00 0 S
1228 Rule Vanc 1947 1961 - Sep lastSun 2:00 0 S
1229 Rule Vanc 1962 max - Oct lastSun 2:00 0 S
1230 Rule Vanc 1987 max - Apr Sun>=1 2:00 1:00 D
1231 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1232 Zone America/Vancouver -8:12:28 - LMT 1884
1234 Zone America/Dawson_Creek -8:00:56 - LMT 1884
1235 -8:00 Canada P%sT 1947
1236 -8:00 Vanc P%sT 1972 Aug 30 2:00
1240 # Northwest Territories, Nunavut, Yukon
1242 # From Paul Eggert (1999-10-29):
1243 # Dawson switched to PST in 1973. Inuvik switched to MST in 1979.
1244 # Mathew Englander <mathew@io.org> (1996-10-07) gives the following refs:
1245 # * 1967. Paragraph 28(34)(g) of the Interpretation Act, S.C. 1967-68,
1246 # c. 7 defines Yukon standard time as UTC-9. This is still valid;
1247 # see Interpretation Act, R.S.C. 1985, c. I-21, s. 35(1).
1248 # * C.O. 1973/214 switched Yukon to PST on 1973-10-28 00:00.
1249 # * O.I.C. 1980/02 established DST.
1250 # * O.I.C. 1987/056 changed DST to Apr firstSun 2:00 to Oct lastSun 2:00.
1251 # Shanks says Yukon's 1973-10-28 switch was at 2:00; go with Englander.
1253 # From Rives McDow (1999-09-04):
1254 # Nunavut ... moved ... to incorporate the whole territory into one time zone.
1255 # <a href="http://www.nunatsiaq.com/nunavut/nvt90903_13.html">
1256 # Nunavut moves to single time zone Oct. 31
1259 # From Antoine Leca (1999-09-06):
1260 # We then need to create a new timezone for the Kitikmeot region of Nunavut
1261 # to differentiate it from the Yellowknife region.
1263 # From Paul Eggert (1999-09-20):
1264 # <a href="http://www.nunavut.com/basicfacts/english/basicfacts_1territory.html">
1265 # Basic Facts: The New Territory
1266 # </a> (1999) reports that Pangnirtung operates on eastern time,
1267 # and that Coral Harbour does not observe DST. We don't know when
1268 # Pangnirtung switched to eastern time; we'll guess 1995.
1269 # We'll ignore the claim about Coral Harbour for now,
1270 # since we have no further info.
1272 # From Rives McDow (1999-11-08):
1273 # On October 31, when the rest of Nunavut went to Central time,
1274 # Pangnirtung wobbled. Here is the result of their wobble:
1276 # The following businesses and organizations in Pangnirtung use Central Time:
1278 # First Air, Power Corp, Nunavut Construction, Health Center, RCMP,
1279 # Eastern Arctic National Parks, A & D Specialist
1281 # The following businesses and organizations in Pangnirtung use Eastern Time:
1283 # Hamlet office, All other businesses, Both schools, Airport operator
1285 # This has made for an interesting situation there, which warranted the news.
1286 # No one there that I spoke with seems concerned, or has plans to
1287 # change the local methods of keeping time, as it evidently does not
1288 # really interfere with any activities or make things difficult locally.
1289 # They plan to celebrate New Year's turn-over twice, one hour apart,
1290 # so it appears that the situation will last at least that long.
1291 # The Nunavut Intergovernmental Affairs hopes that they will "come to
1292 # their senses", but the locals evidently don't see any problem with
1293 # the current state of affairs.
1295 # From Michaela Rodrigue, writing in the
1296 # <a href="http://www.nunatsiaq.com/archives/nunavut991130/nvt91119_17.html">
1297 # Nunatsiaq News (1999-11-19)</a>:
1298 # Clyde River, Pangnirtung and Sanikiluaq now operate with two time zones,
1299 # central - or Nunavut time - for government offices, and eastern time
1300 # for municipal offices and schools.... Igloolik [was similar but then]
1301 # made the switch to central time on Saturday, Nov. 6.
1303 # From Paul Eggert (2000-10-02):
1304 # Matthews and Vincent (1998) say the following, but we lack histories
1305 # for these potential new Zones.
1307 # The Canadian Forces station at Alert uses Eastern Time while the
1308 # handful of residents at the Eureka weather station [in the Central
1309 # zone] skip daylight savings. Baffin Island, which is crossed by the
1310 # Central, Eastern and Atlantic Time zones only uses Eastern Time.
1311 # Gjoa Haven, Taloyoak and Pelly Bay all use Mountain instead of
1312 # Central Time and Southampton Island [in the Central zone] is not
1313 # required to use daylight savings.
1316 # <a href="http://www.nunatsiaq.com/archives/nunavut001130/nvt21110_02.html">
1317 # Nunavut now has two time zones
1318 # </a> (2000-11-10):
1319 # The Nunavut government would allow its employees in Kugluktuk and
1320 # Cambridge Bay to operate on central time year-round, putting them
1321 # one hour behind the rest of Nunavut for six months during the winter.
1322 # At the end of October the two communities had rebelled against
1323 # Nunavut's unified time zone, refusing to shift to eastern time with
1324 # the rest of the territory for the winter. Cambridge Bay remained on
1325 # central time, while Kugluktuk, even farther west, reverted to
1326 # mountain time, which they had used before the advent of Nunavut's
1327 # unified time zone in 1999.
1329 # From Rives McDow (2001-01-20), quoting the Nunavut government:
1330 # The preceding decision came into effect at midnight, Saturday Nov 4, 2000.
1332 # From Paul Eggert (2000-12-04):
1333 # Let's just keep track of the official times for now.
1335 # From Rives McDow (2001-03-07):
1336 # The premier of Nunavut has issued a ministerial statement advising
1337 # that effective 2001-04-01, the territory of Nunavut will revert
1338 # back to three time zones (mountain, central, and eastern). Of the
1339 # cities in Nunavut, Coral Harbor is the only one that I know of that
1340 # has said it will not observe dst, staying on EST year round. I'm
1341 # checking for more info, and will get back to you if I come up with
1343 # [Also see <http://www.nunatsiaq.com/nunavut/nvt10309_06.html> (2001-03-09).]
1345 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
1346 Rule NT_YK 1918 only - Apr 14 2:00 1:00 D
1347 Rule NT_YK 1918 only - Oct 27 2:00 0 S
1348 Rule NT_YK 1919 only - May 25 2:00 1:00 D
1349 Rule NT_YK 1919 only - Nov 1 0:00 0 S
1350 Rule NT_YK 1942 only - Feb 9 2:00 1:00 W # War
1351 Rule NT_YK 1945 only - Aug 14 23:00u 1:00 P # Peace
1352 Rule NT_YK 1945 only - Sep 30 2:00 0 S
1353 Rule NT_YK 1965 only - Apr lastSun 0:00 2:00 DD
1354 Rule NT_YK 1965 only - Oct lastSun 2:00 0 S
1355 Rule NT_YK 1980 1986 - Apr lastSun 2:00 1:00 D
1356 Rule NT_YK 1980 max - Oct lastSun 2:00 0 S
1357 Rule NT_YK 1987 max - Apr Sun>=1 2:00 1:00 D
1358 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1359 Zone America/Pangnirtung -4:22:56 - LMT 1884
1360 -4:00 NT_YK A%sT 1995 Apr Sun>=1 2:00
1361 -5:00 Canada E%sT 1999 Oct 31 2:00
1362 -6:00 Canada C%sT 2000 Oct 29 2:00
1364 Zone America/Iqaluit -4:33:52 - LMT 1884 # Frobisher Bay before 1987
1365 -5:00 NT_YK E%sT 1999 Oct 31 2:00
1366 -6:00 Canada C%sT 2000 Oct 29 2:00
1368 Zone America/Rankin_Inlet -6:08:40 - LMT 1884
1369 -6:00 NT_YK C%sT 2000 Oct 29 2:00
1370 -5:00 - EST 2001 Apr 1 3:00
1372 Zone America/Cambridge_Bay -7:00:20 - LMT 1884
1373 -7:00 NT_YK M%sT 1999 Oct 31 2:00
1374 -6:00 Canada C%sT 2000 Oct 29 2:00
1375 -5:00 - EST 2000 Nov 5 0:00
1376 -6:00 - CST 2001 Apr 1 3:00
1378 Zone America/Yellowknife -7:37:24 - LMT 1884
1380 Zone America/Inuvik -8:54:00 - LMT 1884
1381 -8:00 NT_YK P%sT 1979 Apr lastSun 2:00
1383 Zone America/Whitehorse -9:00:12 - LMT 1900 Aug 20
1384 -9:00 NT_YK Y%sT 1966 Jul 1 2:00
1386 Zone America/Dawson -9:17:40 - LMT 1900 Aug 20
1387 -9:00 NT_YK Y%sT 1973 Oct 28 0:00
1391 ###############################################################################
1395 # From Paul Eggert (2001-03-05):
1396 # The Investigation and Analysis Service of the
1397 # Mexican Library of Congress (MLoC) has published a
1398 # <a href="http://www.cddhcu.gob.mx/bibliot/publica/inveyana/polisoc/horver/">
1399 # history of Mexican local time (in Spanish)
1402 # Here are the discrepancies between Shanks and the MLoC.
1403 # (In all cases we go with the MLoC.)
1404 # Shanks reports that Baja was at -8:00 in 1922/1923.
1405 # Shanks says the 1930 transition in Baja was 1930-11-16.
1406 # Shanks reports no DST during summer 1931.
1407 # Shanks reports a transition at 1032-03-30 23:00, not 1932-04-01.
1408 # Shanks does not report transitions for Baja in 1945 or 1948.
1409 # Shanks reports southern Mexico transitions on 1981-12-01, not 12-23.
1410 # Shanks says Quintana Roo switched to -6:00 on 1982-12-02, and to -5:00
1411 # on 1997-10-26 at 02:00.
1413 # From Gwillim Law (2001-02-20):
1414 # There are some other discrepancies between the Decrees page and the
1415 # tz database. I think they can best be explained by supposing that
1416 # the researchers who prepared the Decrees page failed to find some of
1417 # the relevant documents.
1419 # From Paul Eggert (2000-07-26):
1420 # Shanks gives 1942-04-01 instead of 1942-04-24, and omits the 1981
1421 # and 1988 DST experiments. Go with spin.com.mx.
1423 # From Alan Perry <alan.perry@eng.sun.com> (1996-02-15):
1424 # A guy from our Mexico subsidiary finally found the Presidential Decree
1425 # outlining the timezone changes in Mexico.
1427 # ------------- Begin Forwarded Message -------------
1429 # I finally got my hands on the Official Presidential Decree that sets up the
1430 # rules for the DST changes. The rules are:
1432 # 1. The country is divided in 3 timezones:
1433 # - Baja California Norte (the Mexico/BajaNorte TZ)
1434 # - Baja California Sur, Nayarit, Sinaloa and Sonora (the Mexico/BajaSur TZ)
1435 # - The rest of the country (the Mexico/General TZ)
1437 # 2. From the first Sunday in April at 2:00 AM to the last Sunday in October
1438 # at 2:00 AM, the times in each zone are as follows:
1443 # 3. The rest of the year, the times are as follows:
1448 # The Decree was published in Mexico's Official Newspaper on January 4th.
1450 # -------------- End Forwarded Message --------------
1451 # From Paul Eggert (1996-06-12):
1452 # For an English translation of the decree, see
1453 # <a href="http://mexico-travel.com/extra/timezone_eng.html">
1454 # ``Diario Oficial: Time Zone Changeover'' (1996-01-04).
1457 # From Rives McDow (1998-10-08):
1458 # The State of Quintana Roo has reverted back to central STD and DST times
1459 # (i.e. UTC -0600 and -0500 as of 1998-08-02).
1461 # From Rives McDow (2000-01-10):
1462 # Effective April 4, 1999 at 2:00 AM local time, Sonora changed to the time
1463 # zone 5 hours from the International Date Line, and will not observe daylight
1464 # savings time so as to stay on the same time zone as the southern part of
1465 # Arizona year round.
1467 # From Jesper Norgaard, translating
1468 # <http://www.reforma.com/nacional/articulo/064327/> (2001-01-17):
1469 # In Oaxaca, the 55.000 teachers from the Section 22 of the National
1470 # Syndicate of Education Workers, refuse to apply daylight saving each
1471 # year, so that the more than 10,000 schools work at normal hour the
1474 # From Gwillim Law (2001-01-19):
1475 # <http://www.reforma.com/negocios_y_dinero/articulo/064481/> ... says
1477 # January 17, 2000 - The Energy Secretary, Ernesto Martens, announced
1478 # that Summer Time will be reduced from seven to five months, starting
1480 # <http://www.publico.com.mx/scripts/texto3.asp?action=pagina&pag=21&pos=p&secc=naci&date=01/17/2001>
1481 # [translated], says "summer time will ... take effect on the first Sunday
1482 # in May, and end on the last Sunday of September.
1484 # From Arthur David Olson (2001-01-25):
1485 # The 2001-01-24 traditional Washington Post contained the page one
1486 # story "Timely Issue Divides Mexicans."...
1487 # http://www.washingtonpost.com/wp-dyn/articles/A37383-2001Jan23.html
1488 # ... Mexico City Mayor Lopez Obrador "...is threatening to keep
1489 # Mexico City and its 20 million residents on a different time than
1490 # the rest of the country..." In particular, Lopez Obrador would abolish
1491 # observation of Daylight Saving Time.
1493 # <a href="http://www.conae.gob.mx/ahorro/decretohorver2001.html#decre">
1494 # Official statute published by the Energy Department
1495 # </a> (2001-02-01) shows Baja and Chihauhua as still using US DST rules,
1496 # and Sonora with no DST. This was reported by Jesper Norgaard (2001-02-03).
1498 # From Paul Eggert (2001-03-03):
1500 # <a href="http://www.latimes.com/news/nation/20010303/t000018766.html">
1501 # James F. Smith writes in today's LA Times
1503 # * Sonora will continue to observe standard time.
1504 # * Last week Mexico City's mayor Andres Manuel Lopez Obrador decreed that
1505 # the Federal District will not adopt DST.
1506 # * 4 of 16 district leaders announced they'll ignore the decree.
1507 # * The decree does not affect federal-controlled facilities including
1508 # the airport, banks, hospitals, and schools.
1510 # For now we'll assume that the Federal District will bow to federal rules.
1512 # From Jesper Norgaard (2001-04-01):
1513 # I found some references to the Mexican application of daylight
1514 # saving, which modifies what I had already sent you, stating earlier
1515 # that a number of northern Mexican states would go on daylight
1516 # saving. The modification reverts this to only cover Baja California
1517 # (Norte), while all other states (except Sonora, who has no daylight
1518 # saving all year) will follow the original decree of president
1519 # Vicente Fox, starting daylight saving May 6, 2001 and ending
1520 # September 30, 2001.
1521 # References: "Diario de Monterrey" <www.diariodemonterrey.com/index.asp>
1522 # Palabra <http://palabra.infosel.com/010331/primera/ppri3101.pdf> (2001-03-31)
1524 # From Reuters (2001-09-04):
1525 # Mexico's Supreme Court on Tuesday declared that daylight savings was
1526 # unconstitutional in Mexico City, creating the possibility the
1527 # capital will be in a different time zone from the rest of the nation
1528 # next year.... The Supreme Court's ruling takes effect at 2:00
1529 # a.m. (0800 GMT) on Sept. 30, when Mexico is scheduled to revert to
1530 # standard time. "This is so residents of the Federal District are not
1531 # subject to unexpected time changes," a statement from the court said.
1533 # From Jesper Norgaard Welen (2002-03-12):
1534 # ... consulting my local grocery store(!) and my coworkers, they all insisted
1535 # that a new decision had been made to reinstate US style DST in Mexico....
1536 # http://www.conae.gob.mx/ahorro/horaver2001_m1_2002.html (2002-02-20)
1537 # confirms this. Sonora as usual is the only state where DST is not applied.
1539 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
1540 Rule Mexico 1939 only - Feb 5 0:00 1:00 D
1541 Rule Mexico 1939 only - Jun 25 0:00 0 S
1542 Rule Mexico 1940 only - Dec 9 0:00 1:00 D
1543 Rule Mexico 1941 only - Apr 1 0:00 0 S
1544 Rule Mexico 1943 only - Dec 16 0:00 1:00 W # War
1545 Rule Mexico 1944 only - May 1 0:00 0 S
1546 Rule Mexico 1950 only - Feb 12 0:00 1:00 D
1547 Rule Mexico 1950 only - Jul 30 0:00 0 S
1548 Rule Mexico 1996 2000 - Apr Sun>=1 2:00 1:00 D
1549 Rule Mexico 1996 2000 - Oct lastSun 2:00 0 S
1550 Rule Mexico 2001 only - May Sun>=1 2:00 1:00 D
1551 Rule Mexico 2001 only - Sep lastSun 2:00 0 S
1552 Rule Mexico 2002 max - Apr Sun>=1 2:00 1:00 D
1553 Rule Mexico 2002 max - Oct lastSun 2:00 0 S
1554 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1556 Zone America/Cancun -5:47:04 - LMT 1922 Jan 1 0:12:56
1557 -6:00 - CST 1981 Dec 23
1558 -5:00 Mexico E%sT 1998 Aug 2 2:00
1561 Zone America/Merida -5:58:28 - LMT 1922 Jan 1 0:01:32
1562 -6:00 - CST 1981 Dec 23
1563 -5:00 - EST 1982 Dec 2
1565 # Coahuila, Durango, Nuevo Leon, Tamaulipas
1566 Zone America/Monterrey -6:41:16 - LMT 1921 Dec 31 23:18:44
1571 Zone America/Mexico_City -6:36:36 - LMT 1922 Jan 1 0:23:24
1572 -7:00 - MST 1927 Jun 10 23:00
1573 -6:00 - CST 1930 Nov 15
1574 -7:00 - MST 1931 May 1 23:00
1575 -6:00 - CST 1931 Oct
1576 -7:00 - MST 1932 Apr 1
1577 -6:00 Mexico C%sT 2001 Sep 30 02:00
1578 -6:00 - CST 2002 Feb 20
1581 Zone America/Chihuahua -7:04:20 - LMT 1921 Dec 31 23:55:40
1582 -7:00 - MST 1927 Jun 10 23:00
1583 -6:00 - CST 1930 Nov 15
1584 -7:00 - MST 1931 May 1 23:00
1585 -6:00 - CST 1931 Oct
1586 -7:00 - MST 1932 Apr 1
1588 -6:00 Mexico C%sT 1998
1589 -6:00 - CST 1998 Apr Sun>=1 3:00
1592 Zone America/Hermosillo -7:23:52 - LMT 1921 Dec 31 23:36:08
1593 -7:00 - MST 1927 Jun 10 23:00
1594 -6:00 - CST 1930 Nov 15
1595 -7:00 - MST 1931 May 1 23:00
1596 -6:00 - CST 1931 Oct
1597 -7:00 - MST 1932 Apr 1
1598 -6:00 - CST 1942 Apr 24
1599 -7:00 - MST 1949 Jan 14
1601 -7:00 Mexico M%sT 1999
1603 # Baja California Sur, Nayarit, Sinaloa
1604 Zone America/Mazatlan -7:05:40 - LMT 1921 Dec 31 23:54:20
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
1610 -6:00 - CST 1942 Apr 24
1611 -7:00 - MST 1949 Jan 14
1615 Zone America/Tijuana -7:48:04 - LMT 1922 Jan 1 0:11:56
1617 -8:00 - PST 1927 Jun 10 23:00
1618 -7:00 - MST 1930 Nov 15
1619 -8:00 - PST 1931 Apr 1
1620 -8:00 1:00 PDT 1931 Sep 30
1621 -8:00 - PST 1942 Apr 24
1622 -8:00 1:00 PWT 1945 Nov 12
1623 -8:00 - PST 1948 Apr 5
1624 -8:00 1:00 PDT 1949 Jan 14
1629 -8:00 Mexico P%sT 2001
1630 -8:00 US P%sT 2002 Feb 20
1632 # From Paul Eggert (2001-03-05):
1633 # Formerly there was an America/Ensenada zone, which differed from
1634 # America/Tijuana only in that it did not observe DST from 1976
1635 # through 1995. This was as per Shanks. However, Guy Harris reports
1636 # that the 1987 OAG says "Only Ensenada, Mexicale, San Felipe and
1637 # Tijuana observe DST," which contradicts Shanks but does imply that
1638 # DST-observance was a town-by-town matter back then. This concerns
1639 # data after 1970 so most likely there should be at least one Zone
1640 # other than America/Tijuana for Baja, but it's not clear yet what its
1641 # name or contents should be.
1646 ###############################################################################
1649 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1650 Zone America/Anguilla -4:12:16 - LMT 1912 Mar 2
1653 # Antigua and Barbuda
1654 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1655 Zone America/Antigua -4:07:12 - LMT 1912 Mar 2
1660 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
1661 Rule Bahamas 1964 max - Oct lastSun 2:00 0 S
1662 Rule Bahamas 1964 1986 - Apr lastSun 2:00 1:00 D
1663 Rule Bahamas 1987 max - Apr Sun>=1 2:00 1:00 D
1664 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1665 Zone America/Nassau -5:09:24 - LMT 1912 Mar 2
1669 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
1670 Rule Barb 1977 only - Jun 12 2:00 1:00 D
1671 Rule Barb 1977 1978 - Oct Sun>=1 2:00 0 S
1672 Rule Barb 1978 1980 - Apr Sun>=15 2:00 1:00 D
1673 Rule Barb 1979 only - Sep 30 2:00 0 S
1674 Rule Barb 1980 only - Sep 25 2:00 0 S
1675 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1676 Zone America/Barbados -3:58:28 - LMT 1924 # Bridgetown
1677 -3:58:28 - BMT 1932 # Bridgetown Mean Time
1681 # Whitman entirely disagrees with Shanks; go with Shanks.
1682 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
1683 Rule Belize 1918 1942 - Oct Sun>=2 0:00 0:30 HD
1684 Rule Belize 1919 1943 - Feb Sun>=9 0:00 0 S
1685 Rule Belize 1973 only - Dec 5 0:00 1:00 D
1686 Rule Belize 1974 only - Feb 9 0:00 0 S
1687 Rule Belize 1982 only - Dec 18 0:00 1:00 D
1688 Rule Belize 1983 only - Feb 12 0:00 0 S
1689 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1690 Zone America/Belize -5:52:48 - LMT 1912 Apr
1694 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1695 Zone Atlantic/Bermuda -4:19:04 - LMT 1930 Jan 1 2:00 # Hamilton
1696 -4:00 - AST 1974 Apr 28 2:00
1700 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1701 Zone America/Cayman -5:25:32 - LMT 1890 # Georgetown
1702 -5:07:12 - KMT 1912 Feb # Kingston Mean Time
1706 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
1707 Rule CR 1979 1980 - Feb lastSun 0:00 1:00 D
1708 Rule CR 1979 1980 - Jun Sun>=1 0:00 0 S
1709 Rule CR 1991 1992 - Jan Sat>=15 0:00 1:00 D
1710 # IATA SSIM (1991-09) says the following was at 1:00; go with Shanks.
1711 Rule CR 1991 only - Jul 1 0:00 0 S
1712 Rule CR 1992 only - Mar 15 0:00 0 S
1713 # There are too many San Joses elsewhere, so we'll use `Costa Rica'.
1714 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1715 Zone America/Costa_Rica -5:36:20 - LMT 1890 # San Jose
1716 -5:36:20 - SJMT 1921 Jan 15 # San Jose Mean Time
1719 # no information; probably like America/Costa_Rica
1723 # From Arthur David Olson (1999-03-29):
1724 # The 1999-03-28 exhibition baseball game held in Havana, Cuba, between
1725 # the Cuban National Team and the Baltimore Orioles was carried live on
1726 # the Orioles Radio Network, including affiliate WTOP in Washington, DC.
1727 # During the game, play-by-play announcer Jim Hunter noted that
1728 # "We'll be losing two hours of sleep...Cuba switched to Daylight Saving
1729 # Time today." (The "two hour" remark referred to losing one hour of
1730 # sleep on 1999-03-28--when the announcers were in Cuba as it switched
1731 # to DST--and one more hour on 1999-04-04--when the announcers will have
1732 # returned to Baltimore, which switches on that date.)
1734 # From Evert van der Veer via Steffen Thorsen (2004-10-28):
1735 # Cuba is not going back to standard time this year.
1736 # From Paul Eggert (2004-10-28):
1737 # http://www.granma.cu/ingles/2004/septiembre/juev30/41medid-i.html
1738 # says that it's due to a problem at the Antonio Guiteras
1739 # thermoelectric plant, and says "This October there will be no return
1740 # to normal hours (after daylight saving time)".
1741 # For now, let's assume that it's a one-year temporary measure.
1743 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
1744 Rule Cuba 1928 only - Jun 10 0:00 1:00 D
1745 Rule Cuba 1928 only - Oct 10 0:00 0 S
1746 Rule Cuba 1940 1942 - Jun Sun>=1 0:00 1:00 D
1747 Rule Cuba 1940 1942 - Sep Sun>=1 0:00 0 S
1748 Rule Cuba 1945 1946 - Jun Sun>=1 0:00 1:00 D
1749 Rule Cuba 1945 1946 - Sep Sun>=1 0:00 0 S
1750 Rule Cuba 1965 only - Jun 1 0:00 1:00 D
1751 Rule Cuba 1965 only - Sep 30 0:00 0 S
1752 Rule Cuba 1966 only - May 29 0:00 1:00 D
1753 Rule Cuba 1966 only - Oct 2 0:00 0 S
1754 Rule Cuba 1967 only - Apr 8 0:00 1:00 D
1755 Rule Cuba 1967 1968 - Sep Sun>=8 0:00 0 S
1756 Rule Cuba 1968 only - Apr 14 0:00 1:00 D
1757 Rule Cuba 1969 1977 - Apr lastSun 0:00 1:00 D
1758 Rule Cuba 1969 1971 - Oct lastSun 0:00 0 S
1759 Rule Cuba 1972 1974 - Oct 8 0:00 0 S
1760 Rule Cuba 1975 1977 - Oct lastSun 0:00 0 S
1761 Rule Cuba 1978 only - May 7 0:00 1:00 D
1762 Rule Cuba 1978 1990 - Oct Sun>=8 0:00 0 S
1763 Rule Cuba 1979 1980 - Mar Sun>=15 0:00 1:00 D
1764 Rule Cuba 1981 1985 - May Sun>=5 0:00 1:00 D
1765 Rule Cuba 1986 1989 - Mar Sun>=14 0:00 1:00 D
1766 Rule Cuba 1990 1997 - Apr Sun>=1 0:00 1:00 D
1767 Rule Cuba 1991 1995 - Oct Sun>=8 0:00s 0 S
1768 Rule Cuba 1996 only - Oct 6 0:00s 0 S
1769 Rule Cuba 1997 only - Oct 12 0:00s 0 S
1770 Rule Cuba 1998 1999 - Mar lastSun 0:00s 1:00 D
1771 Rule Cuba 1998 2003 - Oct lastSun 0:00s 0 S
1772 Rule Cuba 2000 max - Apr Sun>=1 0:00s 1:00 D
1773 Rule Cuba 2005 max - Oct lastSun 0:00s 0 S
1775 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1776 Zone America/Havana -5:29:28 - LMT 1890
1777 -5:29:36 - HMT 1925 Jul 19 12:00 # Havana MT
1781 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1782 Zone America/Dominica -4:05:36 - LMT 1911 Jul 1 0:01 # Roseau
1785 # Dominican Republic
1787 # From Steffen Thorsen (2000-10-30):
1788 # Enrique Morales reported to me that the Dominican Republic has changed the
1789 # time zone to Eastern Standard Time as of Sunday 29 at 2 am....
1790 # http://www.listin.com.do/antes/261000/republica/princi.html
1792 # From Paul Eggert (2000-12-04):
1793 # That URL (2000-10-26, in Spanish) says they planned to use US-style DST.
1795 # From Rives McDow (2000-12-01):
1796 # Dominican Republic changed its mind and presidential decree on Tuesday,
1797 # November 28, 2000, with a new decree. On Sunday, December 3 at 1:00 AM the
1798 # Dominican Republic will be reverting to 8 hours from the International Date
1799 # Line, and will not be using DST in the foreseeable future. The reason they
1800 # decided to use DST was to be in synch with Puerto Rico, who was also going
1801 # to implement DST. When Puerto Rico didn't implement DST, the president
1802 # decided to revert.
1805 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
1806 Rule DR 1966 only - Oct 30 0:00 1:00 D
1807 Rule DR 1967 only - Feb 28 0:00 0 S
1808 Rule DR 1969 1973 - Oct lastSun 0:00 0:30 HD
1809 Rule DR 1970 only - Feb 21 0:00 0 S
1810 Rule DR 1971 only - Jan 20 0:00 0 S
1811 Rule DR 1972 1974 - Jan 21 0:00 0 S
1812 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1813 Zone America/Santo_Domingo -4:39:36 - LMT 1890
1814 -4:40 - SDMT 1933 Apr 1 12:00 # S. Dom. MT
1815 -5:00 DR E%sT 1974 Oct 27
1816 -4:00 - AST 2000 Oct 29 02:00
1817 -5:00 US E%sT 2000 Dec 3 01:00
1821 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
1822 Rule Salv 1987 1988 - May Sun>=1 0:00 1:00 D
1823 Rule Salv 1987 1988 - Sep lastSun 0:00 0 S
1824 # There are too many San Salvadors elsewhere, so use America/El_Salvador
1825 # instead of America/San_Salvador.
1826 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1827 Zone America/El_Salvador -5:56:48 - LMT 1921 # San Salvador
1831 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1832 Zone America/Grenada -4:07:00 - LMT 1911 Jul # St George's
1836 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1837 Zone America/Guadeloupe -4:06:08 - LMT 1911 Jun 8 # Pointe a Pitre
1841 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
1842 Rule Guat 1973 only - Nov 25 0:00 1:00 D
1843 Rule Guat 1974 only - Feb 24 0:00 0 S
1844 Rule Guat 1983 only - May 21 0:00 1:00 D
1845 Rule Guat 1983 only - Sep 22 0:00 0 S
1846 Rule Guat 1991 only - Mar 23 0:00 1:00 D
1847 Rule Guat 1991 only - Sep 7 0:00 0 S
1848 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1849 Zone America/Guatemala -6:02:04 - LMT 1918 Oct 5
1853 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
1854 Rule Haiti 1983 only - May 8 0:00 1:00 D
1855 Rule Haiti 1984 1987 - Apr lastSun 0:00 1:00 D
1856 Rule Haiti 1983 1987 - Oct lastSun 0:00 0 S
1857 # Shanks says AT is 2:00, but IATA SSIM (1991/1997) says 1:00s. Go with IATA.
1858 Rule Haiti 1988 1997 - Apr Sun>=1 1:00s 1:00 D
1859 Rule Haiti 1988 1997 - Oct lastSun 1:00s 0 S
1860 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1861 Zone America/Port-au-Prince -4:49:20 - LMT 1890
1862 -4:49 - PPMT 1917 Jan 24 12:00 # P-a-P MT
1866 # Shanks says 1921 Jan 1; go with Whitman's more precise Apr 1.
1867 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1868 Zone America/Tegucigalpa -5:48:52 - LMT 1921 Apr
1871 # Great Swan I ceded by US to Honduras in 1972
1875 # From Bob Devine (1988-01-28):
1878 # From U. S. Naval Observatory (1989-01-19):
1879 # JAMAICA 5 H BEHIND UTC
1882 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1883 Zone America/Jamaica -5:07:12 - LMT 1890 # Kingston
1884 -5:07:12 - KMT 1912 Feb # Kingston Mean Time
1885 -5:00 - EST 1974 Apr 28 2:00
1890 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1891 Zone America/Martinique -4:04:20 - LMT 1890 # Fort-de-France
1892 -4:04:20 - FFMT 1911 May # Fort-de-France MT
1893 -4:00 - AST 1980 Apr 6
1894 -4:00 1:00 ADT 1980 Sep 28
1898 # From Paul Eggert (1997-08-31):
1899 # Recent volcanic eruptions have forced evacuation of Plymouth, the capital.
1900 # Luckily, Olveston, the current de facto capital, has the same longitude.
1901 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1902 Zone America/Montserrat -4:08:52 - LMT 1911 Jul 1 0:01 # Olveston
1907 # From Steffen Thorsen (1998-12-29):
1908 # Nicaragua seems to be back at -6:00 but I have not been able to find when
1909 # they changed from -5:00.
1911 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
1912 Rule Nic 1979 1980 - Mar Sun>=16 0:00 1:00 D
1913 Rule Nic 1979 1980 - Jun Mon>=23 0:00 0 S
1914 Rule Nic 1992 only - Jan 1 4:00 1:00 D
1915 Rule Nic 1992 only - Sep 24 0:00 0 S
1916 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1917 Zone America/Managua -5:45:08 - LMT 1890
1918 -5:45:12 - MMT 1934 Jun 23 # Managua Mean Time?
1919 -6:00 - CST 1973 May
1920 -5:00 - EST 1975 Feb 16
1921 -6:00 Nic C%sT 1993 Jan 1 4:00
1922 -5:00 - EST 1998 Dec
1926 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1927 Zone America/Panama -5:18:08 - LMT 1890
1928 -5:19:36 - CMT 1908 Apr 22 # Colon Mean Time
1932 # There are too many San Juans elsewhere, so we'll use `Puerto_Rico'.
1933 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1934 Zone America/Puerto_Rico -4:24:25 - LMT 1899 Mar 28 12:00 # San Juan
1935 -4:00 - AST 1942 May 3
1936 -4:00 1:00 AWT 1945 Sep 30 2:00
1940 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1941 Zone America/St_Kitts -4:10:52 - LMT 1912 Mar 2 # Basseterre
1945 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1946 Zone America/St_Lucia -4:04:00 - LMT 1890 # Castries
1947 -4:04:00 - CMT 1912 # Castries Mean Time
1950 # St Pierre and Miquelon
1951 # There are too many St Pierres elsewhere, so we'll use `Miquelon'.
1952 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1953 Zone America/Miquelon -3:44:40 - LMT 1911 May 15 # St Pierre
1954 -4:00 - AST 1980 May
1955 -3:00 - PMST 1987 # Pierre & Miquelon Time
1958 # St Vincent and the Grenadines
1959 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1960 Zone America/St_Vincent -4:04:56 - LMT 1890 # Kingstown
1961 -4:04:56 - KMT 1912 # Kingstown Mean Time
1965 # From Paul Eggert (1998-08-06):
1966 # Shanks says they use US DST rules, but IATA SSIM (1991/1998)
1967 # says they switch at midnight. Go with IATA SSIM.
1968 # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
1969 Rule TC 1979 1986 - Apr lastSun 0:00 1:00 D
1970 Rule TC 1979 max - Oct lastSun 0:00 0 S
1971 Rule TC 1987 max - Apr Sun>=1 0:00 1:00 D
1972 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1973 Zone America/Grand_Turk -4:44:32 - LMT 1890
1974 -5:07:12 - KMT 1912 Feb # Kingston Mean Time
1978 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1979 Zone America/Tortola -4:18:28 - LMT 1911 Jul # Road Town
1983 # Zone NAME GMTOFF RULES FORMAT [UNTIL]
1984 Zone America/St_Thomas -4:19:44 - LMT 1911 Jul # Charlotte Amalie