1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
|
# $OpenBSD: northamerica,v 1.13 2001/03/28 13:33:44 millert Exp $
# @(#)northamerica 7.56
# also includes Central America and the Caribbean
# This data is by no means authoritative; if you think you know better,
# go ahead and edit the file (and please send any changes to
# tz@elsie.nci.nih.gov for general use in the future).
# From Paul Eggert <eggert@twinsun.com> (1999-03-22):
# A reliable and entertaining source about time zones is
# Derek Howse, Greenwich time and longitude, Philip Wilson Publishers (1997).
###############################################################################
# United States
# From Paul Eggert (1999-03-31):
# Howse writes (pp 121-125) that time zones were invented by
# Professor Charles Ferdinand Dowd (1825-1904),
# Principal of Temple Grove Ladies' Seminary (Saratoga Springs, NY).
# His pamphlet ``A System of National Time for Railroads'' (1870)
# was the result of his proposals at the Convention of Railroad Trunk Lines
# in New York City (1869-10). His 1870 proposal was based on Washington, DC,
# but in 1872-05 he moved the proposed origin to Greenwich.
# His proposal was adopted by the railroads on 1883-11-18 at 12:00,
# and the most of the country soon followed suit.
# From Paul Eggert <eggert@twinsun.com> (1995-12-19):
# A good source for time zone historical data in the US is
# Thomas G. Shanks, The American Atlas (5th edition),
# San Diego: ACS Publications, Inc. (1991).
# Make sure you have the errata sheet; the book is somewhat useless without it.
# It is the source for the US and Puerto Rico entries below.
# From Paul Eggert (2001-03-06):
# Daylight Saving Time was first suggested as a joke by Benjamin Franklin
# in his whimsical essay ``An Economical Project for Diminishing the Cost
# of Light'' published in the Journal de Paris (1784-04-26).
# Not everyone is happy with the results:
#
# I don't really care how time is reckoned so long as there is some
# agreement about it, but I object to being told that I am saving
# daylight when my reason tells me that I am doing nothing of the kind.
# I even object to the implication that I am wasting something
# valuable if I stay in bed after the sun has risen. As an admirer
# of moonlight I resent the bossy insistence of those who want to
# reduce my time for enjoying it. At the back of the Daylight Saving
# scheme I detect the bony, blue-fingered hand of Puritanism, eager
# to push people into bed earlier, and get them up earlier, to make
# them healthy, wealthy and wise in spite of themselves.
#
# -- Robertson Davies, The Diary of Samuel Marchbanks (1947), XIX, Sunday
#
# For more about the first ten years of DST in the United States, see
# Robert Garland's <a href="http://www.clpgh.org/exhibit/dst.html">
# Ten years of daylight saving from the Pittsburgh standpoint
# (Carnegie Library of Pittsburgh, 1927)</a>.
#
# Shanks says that DST was called "War Time" in the US in 1918 and 1919.
# However, DST was imposed by the Standard Time Act of 1918, which
# was the first nationwide legal time standard, and apparently
# time was just called "Standard Time" or "Daylight Saving Time".
# From Arthur David Olson:
# US Daylight Saving Time ended on the last Sunday of *October* in 1974.
# See, for example, the front page of the Saturday, 1974-10-26
# and Sunday, 1974-10-27 editions of the Washington Post.
# From Arthur David Olson:
# Before the Uniform Time Act of 1966 took effect in 1967, observance of
# Daylight Saving Time in the US was by local option, except during wartime.
# From Arthur David Olson (2000-09-25):
# Last night I heard part of a rebroadcast of a 1945 Arch Oboler radio drama.
# In the introduction, Oboler spoke of "Eastern Peace Time."
# An AltaVista search turned up
# <a href="http://rowayton.org/rhs/hstaug45.html">:
# "When the time is announced over the radio now, it is 'Eastern Peace
# Time' instead of the old familiar 'Eastern War Time.' Peace is wonderful."
# </a> (August 1945) by way of confirmation.
# From Joseph Gallant <notquite@hotmail.com>, citing
# George H. Douglas, _The Early Days of Radio Broadcasting_ (1987):
# At 7 P.M. (Eastern War Time) [on 1945-08-14], the networks were set
# to switch to London for Atlee's address, but the American people
# never got to hear his speech live. According to one press account,
# CBS' Bob Trout was first to announce the word of Japan's surrender,
# but a few seconds later, NBC, ABC and Mutual also flashed the word
# of surrender, all of whom interrupting the bells of Big Ben in
# London which were to precede Mr. Atlee's speech.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule US 1918 1919 - Mar lastSun 2:00 1:00 D
Rule US 1918 1919 - Oct lastSun 2:00 0 S
Rule US 1942 only - Feb 9 2:00 1:00 W # War
Rule US 1945 only - Aug 14 23:00u 1:00 P # Peace
Rule US 1945 only - Sep 30 2:00 0 S
Rule US 1967 max - Oct lastSun 2:00 0 S
Rule US 1967 1973 - Apr lastSun 2:00 1:00 D
Rule US 1974 only - Jan 6 2:00 1:00 D
Rule US 1975 only - Feb 23 2:00 1:00 D
Rule US 1976 1986 - Apr lastSun 2:00 1:00 D
Rule US 1987 max - Apr Sun>=1 2:00 1:00 D
# <a href="http://thomas.loc.gov/cgi-bin/bdquery/z?d106:h.r.00177:">
# H.R.177
# </a> (introduced 1999-01-06) would change April to March in the above rule.
# From Bob Devine (1988-01-28):
# ...Alaska (and Hawaii) had the timezone names changed in 1967.
# old new
# Pacific Standard Time(PST) -same-
# Yukon Standard Time(YST) -same-
# Central Alaska S.T. (CAT) Alaska-Hawaii St[an]dard Time (AHST)
# Nome Standard Time (NT) Bering Standard Time (BST)
#
# ...Alaska's timezone lines were redrawn in 1983 to give only 2 tz.
# The YST zone now covers nearly all of the state, AHST just part
# of the Aleutian islands. No DST.
# From Paul Eggert (1995-12-19):
# The tables below use `NST', not `NT', for Nome Standard Time.
# I invented `CAWT' for Central Alaska War Time.
# From U. S. Naval Observatory (1989-01-19):
# USA EASTERN 5 H BEHIND UTC NEW YORK, WASHINGTON
# USA EASTERN 4 H BEHIND UTC APR 3 - OCT 30
# USA CENTRAL 6 H BEHIND UTC CHICAGO, HOUSTON
# USA CENTRAL 5 H BEHIND UTC APR 3 - OCT 30
# USA MOUNTAIN 7 H BEHIND UTC DENVER
# USA MOUNTAIN 6 H BEHIND UTC APR 3 - OCT 30
# USA PACIFIC 8 H BEHIND UTC L.A., SAN FRANCISCO
# USA PACIFIC 7 H BEHIND UTC APR 3 - OCT 30
# USA ALASKA STD 9 H BEHIND UTC MOST OF ALASKA (AKST)
# USA ALASKA STD 8 H BEHIND UTC APR 3 - OCT 30 (AKDT)
# USA ALEUTIAN 10 H BEHIND UTC ISLANDS WEST OF 170W
# USA - " - 9 H BEHIND UTC APR 3 - OCT 30
# USA HAWAII 10 H BEHIND UTC
# USA BERING 11 H BEHIND UTC SAMOA, MIDWAY
# From Arthur David Olson (1989-01-21):
# The above dates are for 1988.
# Note the "AKST" and "AKDT" abbreviations, the claim that there's
# no DST in Samoa, and the claim that there is DST in Alaska and the
# Aleutians.
# From Arthur David Olson (1988-02-13):
# Legal standard time zone names, from United States Code (1982 Edition and
# Supplement III), Title 15, Chapter 6, Section 260 and forward. First, names
# up to 1967-04-01 (when most provisions of the Uniform Time Act of 1966
# took effect), as explained in sections 263 and 261:
# (none)
# United States standard eastern time
# United States standard mountain time
# United States standard central time
# United States standard Pacific time
# (none)
# United States standard Alaska time
# (none)
# Next, names from 1967-04-01 until 1983-11-30 (the date for
# public law 98-181):
# Atlantic standard time
# eastern standard time
# central standard time
# mountain standard time
# Pacific standard time
# Yukon standard time
# Alaska-Hawaii standard time
# Bering standard time
# And after 1983-11-30:
# Atlantic standard time
# eastern standard time
# central standard time
# mountain standard time
# Pacific standard time
# Alaska standard time
# Hawaii-Aleutian standard time
# Samoa standard time
# The law doesn't give abbreviations.
#
# From Paul Eggert (1995-12-19):
# Shanks uses 1983-10-30, not 1983-11-30, for the 1983 transitions.
# Go with Shanks.
#
# From Paul Eggert (2000-01-08), following a heads-up from Rives McDow:
# Public law 106-564 (2000-12-23) introduced the abbreviation
# "Chamorro Standard Time" for time in Guam and the Northern Marianas.
# See the file "australasia".
# From Ryan Alessi of the Thousand Oaks Star (2001-02-15) via Rives McDow:
# Brad Sherman, D-Sherman Oaks, introduced a bill in Congress on
# Wednesday that could have California operating on Denver time as
# early as this summer.... The options include keeping
# daylight-saving time all year long, or setting clocks back two hours
# -- instead of just one -- during the existing daylight-saving time.
# US Eastern time, represented by New York
# Connecticut, Delaware, District of Columbia, most of Florida,
# Georgia, far southeastern Indiana, eastern Kentucky, Maine,
# Maryland, Massachusetts, New Hampshire, New Jersey, New York, North
# Carolina, Ohio, Pennsylvania, Rhode Island, South Carolina, eastern
# Tennessee, Vermont, Virginia, West Virginia
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER
Rule NYC 1920 only - Mar lastSun 2:00 1:00 D
Rule NYC 1920 only - Oct lastSun 2:00 0 S
Rule NYC 1921 1966 - Apr lastSun 2:00 1:00 D
Rule NYC 1921 1954 - Sep lastSun 2:00 0 S
Rule NYC 1955 1966 - Oct lastSun 2:00 0 S
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone America/New_York -4:56:02 - LMT 1883 Nov 18 12:00
-5:00 US E%sT 1920
-5:00 NYC E%sT 1942
-5:00 US E%sT 1946
-5:00 NYC E%sT 1967
-5:00 US E%sT
# US Central time, represented by Chicago
# Alabama, Arkansas, Florida panhandle, Illinois, western Indiana
# corners, Iowa, most of Kansas, western Kentucky, Louisiana,
# Minnesota, Mississippi, Missouri, eastern Nebraska, eastern North
# Dakota, Oklahoma, eastern South Dakota, western Tennessee, most of
# Texas, Wisconsin
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER
Rule Chicago 1920 only - Jun 13 2:00 1:00 D
Rule Chicago 1920 1921 - Oct lastSun 2:00 0 S
Rule Chicago 1921 only - Mar lastSun 2:00 1:00 D
Rule Chicago 1922 1966 - Apr lastSun 2:00 1:00 D
Rule Chicago 1922 1954 - Sep lastSun 2:00 0 S
Rule Chicago 1955 1966 - Oct lastSun 2:00 0 S
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone America/Chicago -5:50:36 - LMT 1883 Nov 18 12:00
-6:00 US C%sT 1920
-6:00 Chicago C%sT 1936 Mar 1 2:00
-5:00 - EST 1936 Nov 15 2:00
-6:00 Chicago C%sT 1942
-6:00 US C%sT 1946
-6:00 Chicago C%sT 1967
-6:00 US C%sT
# US Mountain time, represented by Denver
#
# Colorado, southern Idaho, far western Kansas, Montana, western
# Nebraska, New Mexico, southwestern North Dakota, far eastern Oregon,
# western South Dakota, far western Texas (El Paso County, Hudspeth County,
# and Pine Springs and Nickel Creek in Culberson County), Utah, Wyoming
#
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER
Rule Denver 1920 1921 - Mar lastSun 2:00 1:00 D
Rule Denver 1920 only - Oct lastSun 2:00 0 S
Rule Denver 1921 only - May 22 2:00 0 S
Rule Denver 1965 1966 - Apr lastSun 2:00 1:00 D
Rule Denver 1965 1966 - Oct lastSun 2:00 0 S
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone America/Denver -6:59:56 - LMT 1883 Nov 18 12:00
-7:00 US M%sT 1920
-7:00 Denver M%sT 1942
-7:00 US M%sT 1946
-7:00 Denver M%sT 1967
-7:00 US M%sT
# US Pacific time, represented by Los Angeles
#
# California, northern Idaho, Nevada, most of Oregon, and Washington
#
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER
Rule CA 1948 only - Mar 14 2:00 1:00 D
Rule CA 1949 only - Jan 1 2:00 0 S
Rule CA 1950 1966 - Apr lastSun 2:00 1:00 D
Rule CA 1950 1961 - Sep lastSun 2:00 0 S
Rule CA 1962 1966 - Oct lastSun 2:00 0 S
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone America/Los_Angeles -7:52:58 - LMT 1883 Nov 18 12:00
-8:00 US P%sT 1946
-8:00 CA P%sT 1967
-8:00 US P%sT
# Alaska
# AK%sT is the modern abbreviation for -9:00 per USNO.
#
# From Paul Eggert (1995-12-19):
# Howse writes that Alaska switched from the Julian to the Gregorian calendar,
# and from east-of-GMT to west-of-GMT days, when the US bought it from Russia.
# This was on 1867-10-18. We omit this transition, since we can't represent
# changes from Julian to Gregorian.
#
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone America/Juneau -8:57:41 - LMT 1900 Aug 20 12:00
-8:00 - PST 1942
-8:00 US P%sT 1946
-8:00 - PST 1969
-8:00 US P%sT 1983 Oct 30 2:00
-9:00 US AK%sT
Zone America/Yakutat -9:18:55 - LMT 1900 Aug 20 12:00
-9:00 - YST 1942
-9:00 US Y%sT 1946
-9:00 - YST 1969
-9:00 US Y%sT 1983 Oct 30 2:00
-9:00 US AK%sT
Zone America/Anchorage -9:59:36 - LMT 1900 Aug 20 12:00
-10:00 - CAT 1942
-10:00 US CAT/CAWT 1946
-10:00 - CAT 1967 Apr
-10:00 - AHST 1969
-10:00 US AH%sT 1983 Oct 30 2:00
-9:00 US AK%sT
Zone America/Nome -11:01:38 - LMT 1900 Aug 20 12:00
-11:00 - NST 1942
-11:00 US N%sT 1946
-11:00 - NST 1967 Apr
-11:00 - BST 1969
-11:00 US B%sT 1983 Oct 30 2:00
-9:00 US AK%sT
Zone America/Adak -11:46:38 - LMT 1900 Aug 20 12:00
-11:00 - NST 1942
-11:00 US N%sT 1946
-11:00 - NST 1967 Apr
-11:00 - BST 1969
-11:00 US B%sT 1983 Oct 30 2:00
-10:00 US HA%sT
# Shanks writes that part of southwest Alaska (e.g. Aniak)
# switched from -11:00 to -10:00 on 1968-09-22 at 02:00,
# and another part (e.g. Akiak) made the same switch five weeks later.
# These switches don't quite make our 1970 cutoff.
# Hawaii
#
# From Arthur David Olson:
# And then there's Hawaii.
# DST was observed for one day in 1933;
# standard time was changed by half an hour in 1947;
# it's always standard as of 1986.
#
# From Paul Eggert:
# Shanks says the 1933 experiment lasted for three weeks. Go with Shanks.
#
Zone Pacific/Honolulu -10:31:26 - LMT 1900 Jan 1 12:00
-10:30 - HST 1933 Apr 30 2:00
-10:30 1:00 HDT 1933 May 21 2:00
-10:30 US H%sT 1947 Jun 8 2:00
-10:00 - HST
# Now we turn to US areas that have diverged from the consensus since 1970.
# Arizona mostly uses MST.
Zone America/Phoenix -7:28:18 - LMT 1883 Nov 18 12:00
-7:00 US M%sT 1944 Jan 1 00:01
-7:00 - MST 1944 Mar 17 00:01
-7:00 US M%sT 1944 Oct 1 00:01
-7:00 - MST 1967
-7:00 US M%sT 1968
-7:00 - MST
# From Arthur David Olson (1988-02-13):
# A writer from the Inter Tribal Council of Arizona, Inc.,
# notes in private correspondence dated 12/28/87 that "Presently, only the
# Navajo Nation participates in the Daylight Saving Time policy, due to its
# large size and location in three states." (The "only" means that other
# tribal nations don't use DST.)
Link America/Denver America/Shiprock
# Southern Idaho and eastern Oregon switched four weeks late in 1974.
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone America/Boise -7:44:49 - LMT 1883 Nov 18 12:00
-8:00 US P%sT 1923 May 13 2:00
-7:00 US M%sT 1974
-7:00 - MST 1974 Feb 3 2:00
-7:00 US M%sT
# Indiana
#
# For a map of Indiana's time zone regions, see:
# <a href="http://www.mccsc.edu/time.html">
# What time is it in Indiana?
# </a> (1999-04-06)
#
# From Paul Eggert (1995-12-19):
# Indiana generally observes either EST all year, or CST/CDT,
# but areas near Cincinnati and Louisville use those cities' timekeeping
# and in 1969 and 1970 the whole state observed daylight time;
# and there are other exceptions as noted below.
# Shanks partitions Indiana into 345 regions, each with its own time history,
# and writes ``Even newspaper reports present contradictory information.''
# Fortunately, most of the complexity occurred before our cutoff date of 1970.
#
# Since 1970, EST-only Indiana has been like America/Indianapolis,
# with exceptions noted below for Crawford, Starke, and Switzerland counties.
# The parts of Indiana not listed below have been like America/Chicago,
# America/Louisville, or America/New_York.
#
# Other than Indianapolis, the Indiana place names are so nondescript
# that they would be ambiguous if we left them at the `America' level.
# So we reluctantly put them all in a subdirectory `America/Indiana'.
#
# Most of EST-only Indiana last observed DST in 1970.
# From Paul Eggert (2001-03-06), following a tip by Markus Kuhn:
# Pam Belluck reported in the New York Times (2001-01-31) that the
# Indiana Legislature is considering a bill to adopt DST statewide.
# Her article mentioned Vevay, whose post office observes a different
# time zone than Danner's Hardware across the street.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER
Rule Indianapolis 1941 only - Jun 22 2:00 1:00 D
Rule Indianapolis 1941 1954 - Sep lastSun 2:00 0 S
Rule Indianapolis 1946 1954 - Apr lastSun 2:00 1:00 D
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone America/Indianapolis -5:44:38 - LMT 1883 Nov 18 12:00
-6:00 US C%sT 1920
-6:00 Indianapolis C%sT 1942
-6:00 US C%sT 1946
-6:00 Indianapolis C%sT 1955 Apr 24 2:00
-5:00 - EST 1957 Sep 29 2:00
-6:00 - CST 1958 Apr 27 2:00
-5:00 - EST 1969
-5:00 US E%sT 1971
-5:00 - EST
Link America/Indianapolis America/Indiana/Indianapolis
#
# Part of Crawford County, Indiana, last observed DST in 1975,
# and left its clocks alone in 1974.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER
Rule Marengo 1951 only - Apr lastSun 2:00 1:00 D
Rule Marengo 1951 only - Sep lastSun 2:00 0 S
Rule Marengo 1954 1960 - Apr lastSun 2:00 1:00 D
Rule Marengo 1954 1960 - Sep lastSun 2:00 0 S
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone America/Indiana/Marengo -5:45:23 - LMT 1883 Nov 18 12:00
-6:00 US C%sT 1951
-6:00 Marengo C%sT 1961 Apr 30 2:00
-5:00 - EST 1969
-5:00 US E%sT 1974 Jan 6 2:00
-6:00 1:00 CDT 1974 Oct 27 2:00
-5:00 US E%sT 1976
-5:00 - EST
#
# Starke County, Indiana
# From Arthur David Olson (1991-10-28):
# An article on page A3 of the Sunday, 1991-10-27 Washington Post
# notes that Starke County switched from Central time to Eastern time as of
# 1991-10-27.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER
Rule Starke 1947 1961 - Apr lastSun 2:00 1:00 D
Rule Starke 1947 1954 - Sep lastSun 2:00 0 S
Rule Starke 1955 1956 - Oct lastSun 2:00 0 S
Rule Starke 1957 1958 - Sep lastSun 2:00 0 S
Rule Starke 1959 1961 - Oct lastSun 2:00 0 S
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone America/Indiana/Knox -5:46:30 - LMT 1883 Nov 18 12:00
-6:00 US C%sT 1947
-6:00 Starke C%sT 1962 Apr 29 2:00
-5:00 - EST 1963 Oct 27 2:00
-6:00 US C%sT 1991 Oct 27 2:00
-5:00 - EST
#
# Switzerland County, Indiana, last observed DST in 1972.
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone America/Indiana/Vevay -5:40:16 - LMT 1883 Nov 18 12:00
-6:00 US C%sT 1954 Apr 25 2:00
-5:00 - EST 1969
-5:00 US E%sT 1973
-5:00 - EST
# Part of Kentucky left its clocks alone in 1974.
# This also includes a part of Indiana immediately adjacent to Louisville.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER
Rule Louisville 1921 only - May 1 2:00 1:00 D
Rule Louisville 1921 only - Sep 1 2:00 0 S
Rule Louisville 1941 1961 - Apr lastSun 2:00 1:00 D
Rule Louisville 1941 only - Sep lastSun 2:00 0 S
Rule Louisville 1946 only - Jun 2 2:00 0 S
Rule Louisville 1950 1955 - Sep lastSun 2:00 0 S
Rule Louisville 1956 1960 - Oct lastSun 2:00 0 S
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone America/Louisville -5:43:02 - LMT 1883 Nov 18 12:00
-6:00 US C%sT 1921
-6:00 Louisville C%sT 1942
-6:00 US C%sT 1946
-6:00 Louisville C%sT 1961 Jul 23 2:00
-5:00 - EST 1968
-5:00 US E%sT 1974 Jan 6 2:00
-6:00 1:00 CDT 1974 Oct 27 2:00
-5:00 US E%sT
Link America/Louisville America/Kentucky/Louisville
#
# Wayne, Clinton, and Russell Counties, Kentucky
#
# From
# <a href="http://www.lake-cumberland.com/life/archive/news990129time.shtml">
# Lake Cumberland LIFE
# </a> (1999-01-29) via WKYM-101.7:
# Clinton County has joined Wayne County in asking the DoT to change from
# the Central to the Eastern time zone.... The Wayne County government made
# the same request in December. And while Russell County officials have not
# taken action, the majority of respondents to a poll conducted there in
# August indicated they would like to change to "fast time" also.
# The three Lake Cumberland counties are the farthest east of any U.S.
# location in the Central time zone.
#
# From Rich Wales (2000-08-29):
# After prolonged debate, and despite continuing deep differences of opinion,
# Wayne County (central Kentucky) is switching from Central (-0600) to Eastern
# (-0500) time. They won't "fall back" this year. See Sara Shipley,
# The difference an hour makes, Nando Times (2000-08-29 15:33 -0400).
Zone America/Kentucky/Monticello -5:39:24 - LMT 1883 Nov 18 12:00
-6:00 US C%sT 1946
-6:00 - CST 1968
-6:00 US C%sT 2000 Oct 29 2:00
-5:00 US E%sT
# From Rives McDow (2000-08-30):
# Here ... are all the changes in the US since 1985.
# Kearny County, KS (put all of county on central;
# previously split between MST and CST) ... 1990-10
# Starke County, IN (from CST to EST) ... 1991-10
# Oliver County, ND (from MST to CST) ... 1992-10
# West Wendover, NV (from PST TO MST) ... 1999-10
# Wayne County, KY (from CST to EST) ... 2000-10
# There is another change in the offing; Mercer County, ND is looking
# to change from MT to CT. It is possible that two other ND counties
# (Sioux and Morton) will look to change also. If made, the earliest
# a change would be effective is October 2001.
#
# From Paul Eggert (2000-10-02):
# FIXME: I haven't yet had time to incorporate all the above changes.
# Michigan
#
# From Bob Devine (1988-01-28):
# Michigan didn't observe DST from 1968 to 1973.
#
# From Paul Eggert (1999-03-31):
# Shanks writes that Michigan started using standard time on 1885-09-18,
# but Howse writes (pp 124-125, referring to Popular Astronomy, 1901-01)
# that Detroit kept
#
# local time until 1900 when the City Council decreed that clocks should
# be put back twenty-eight minutes to Central Standard Time. Half the
# city obeyed, half refused. After considerable debate, the decision
# was rescinded and the city reverted to Sun time. A derisive offer to
# erect a sundial in front of the city hall was referred to the
# Committee on Sewers. Then, in 1905, Central time was adopted
# by city vote.
#
# This story is too entertaining to be false, so go with Howse over Shanks.
#
# From Paul Eggert (2001-03-06):
# Garland (1927) writes ``Cleveland and Detroit advanced their clocks
# one hour in 1914.'' This change is not in Shanks. We have no more
# info, so omit this for now.
#
# Most of Michigan observed DST from 1973 on, but was a bit late in 1975.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER
Rule Detroit 1948 only - Apr lastSun 2:00 1:00 D
Rule Detroit 1948 only - Sep lastSun 2:00 0 S
Rule Detroit 1967 only - Jun 14 2:00 1:00 D
Rule Detroit 1967 only - Oct lastSun 2:00 0 S
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone America/Detroit -5:32:11 - LMT 1905
-6:00 - CST 1915 May 15 2:00
-5:00 - EST 1942
-5:00 US E%sT 1946
-5:00 Detroit E%sT 1973
-5:00 US E%sT 1975
-5:00 - EST 1975 Apr 27 2:00
-5:00 US E%sT
#
# The Michigan border with Wisconsin switched from EST to CST/CDT in 1973.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER
Rule Menominee 1946 only - Apr lastSun 2:00 1:00 D
Rule Menominee 1946 only - Sep lastSun 2:00 0 S
Rule Menominee 1966 only - Apr lastSun 2:00 1:00 D
Rule Menominee 1966 only - Oct lastSun 2:00 0 S
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone America/Menominee -5:50:27 - LMT 1885 Sep 18 12:00
-6:00 US C%sT 1946
-6:00 Menominee C%sT 1969 Apr 27 2:00
-5:00 - EST 1973 Apr 29 2:00
-6:00 US C%sT
# Navassa
# claimed by US under the provisions of the 1856 Guano Islands Act
# also claimed by Haiti
# occupied 1857/1900 by the Navassa Phosphate Co
# US lighthouse 1917/1997-01
# currently uninhabited
# see Mark Fineman, ``An Isle Rich in Guano and Discord'',
# _Los Angeles Times_ (1998-11-10), A1, A10; it cites
# Jimmy Skaggs, _The Great Guano Rush_ (1994).
# Old names, for S5 users
# Link LINK-FROM LINK-TO
Link America/New_York EST5EDT
Link America/Chicago CST6CDT
Link America/Denver MST7MDT
Link America/Los_Angeles PST8PDT
Link America/Indianapolis EST
Link America/Phoenix MST
Link Pacific/Honolulu HST
################################################################################
# From Paul Eggert <eggert@twinsun.com> (1999-10-29):
# A good source for time zone historical data outside the US is
# Thomas G. Shanks, The International Atlas (5th edition),
# San Diego: ACS Publications, Inc. (1999).
#
# Gwillim Law <Gwil_Law@bridge-point.com> writes that a good source
# for recent time zone data is the International Air Transport
# Association's Standard Schedules Information Manual (IATA SSIM),
# published semiannually. Law sent in several helpful summaries
# of the IATA's data after 1990.
#
# Except where otherwise noted, Shanks is the source for entries through 1990,
# and IATA SSIM is the source for entries after 1990.
#
# Another source occasionally used is Edward W. Whitman, World Time Differences,
# Whitman Publishing Co, 2 Niagara Av, Ealing, London (undated), which
# I found in the UCLA library.
#
# See the `europe' file for Greenland.
# Canada
# From Alain LaBont<e'> <ALB@immedia.ca> (1994-11-14):
# I post here the time zone abbreviations standardized in Canada
# for both English and French in the CAN/CSA-Z234.4-89 standard....
#
# UTC Standard time Daylight savings time
# offset French English French English
# -2:30 - - HAT NDT
# -3 - - HAA ADT
# -3:30 HNT NST - -
# -4 HNA AST HAE EDT
# -5 HNE EST HAC CDT
# -6 HNC CST HAR MDT
# -7 HNR MST HAP PDT
# -8 HNP PST HAY YDT
# -9 HNY YST - -
#
# HN: Heure Normale ST: Standard Time
# HA: Heure Avanc<e'>e DT: Daylight saving Time
#
# A: de l'Atlantique Atlantic
# C: du Centre Central
# E: de l'Est Eastern
# M: Mountain
# N: Newfoundland
# P: du Pacifique Pacific
# R: des Rocheuses
# T: de Terre-Neuve
# Y: du Yukon Yukon
#
# From Paul Eggert <eggert@twinsun.com> (1994-11-22):
# Alas, this sort of thing must be handled by localization software.
# Unless otherwise specified, the data for Canada are all from Shanks.
# From Paul Eggert (2000-10-02):
# H. David Matthews and Mary Vincent's map
# <a href="http://www.canadiangeographic.ca/SO98/geomap.htm">
# "It's about TIME", _Canadian Geographic_ (September-October 1998)
# </a> contains detailed boundaries for regions observing nonstandard
# time and daylight saving time arrangements in Canada circa 1998.
#
# INMS, the Institute for National Measurement Standards in Ottawa, has
# <a href="http://www.nrc.ca/inms/time/tze.html">
# information about standard and daylight saving time zones in Canada.
# </a> (updated periodically).
# Its unofficial information is often taken from Matthews and Vincent.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Canada 1918 only - Apr 14 2:00 1:00 D
Rule Canada 1918 only - Oct 31 2:00 0 S
Rule Canada 1942 only - Feb 9 2:00 1:00 W
Rule Canada 1945 only - Sep 30 2:00 0 S
Rule Canada 1974 1986 - Apr lastSun 2:00 1:00 D
Rule Canada 1974 max - Oct lastSun 2:00 0 S
Rule Canada 1987 max - Apr Sun>=1 2:00 1:00 D
# Newfoundland (and far southeast Labrador)
# From Paul Eggert (2000-10-02):
# Matthews and Vincent (1998) write that Labrador should use NST/NDT,
# but the only part of Labrador that follows the rules is the
# southeast corner, including Port Hope Simpson and Mary's Harbour,
# but excluding, say, Black Tickle.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule StJohns 1917 1918 - Apr Sun>=8 2:00 1:00 D
Rule StJohns 1917 only - Sep 17 2:00 0 S
Rule StJohns 1918 only - Oct 31 2:00 0 S
# Whitman gives 1919 Apr 5 and 1920 Apr 5; go with Shanks.
Rule StJohns 1919 only - May 5 23:00 1:00 D
Rule StJohns 1919 only - Aug 12 23:00 0 S
# For 1931-1935 Whitman gives Apr same date; go with Shanks.
Rule StJohns 1920 1935 - May Sun>=1 23:00 1:00 D
Rule StJohns 1920 1935 - Oct lastSun 23:00 0 S
# For 1936-1941 Shanks gives May Mon>=9 and Oct Mon>=2; go with Whitman.
Rule StJohns 1936 1941 - May Sun>=8 0:00 1:00 D
Rule StJohns 1936 1941 - Oct Sun>=1 0:00 0 S
# Shanks gives 1942 May 11 - 1945 Sep 30; go with Whitman.
Rule StJohns 1942 only - Mar 1 0:00 1:00 W
Rule StJohns 1942 only - Dec 31 0:00 0 S
Rule StJohns 1943 only - May 30 0:00 1:00 W
Rule StJohns 1943 only - Sep 5 0:00 0 S
Rule StJohns 1944 only - Jul 10 0:00 1:00 W
Rule StJohns 1944 only - Sep 2 0:00 0 S
Rule StJohns 1945 only - Jan 1 0:00 1:00 W
Rule StJohns 1945 only - Oct 7 2:00 0 S
# For 1946-9 Whitman gives May 5,4,9,1 - Oct 1,5,3,2, and for 1950 he gives
# Apr 30 - Sep 24; go with Shanks.
Rule StJohns 1946 1950 - May Sun>=8 2:00 1:00 D
Rule StJohns 1946 1950 - Oct Sun>=2 2:00 0 S
Rule StJohns 1951 1986 - Apr lastSun 2:00 1:00 D
Rule StJohns 1951 1959 - Sep lastSun 2:00 0 S
Rule StJohns 1960 1986 - Oct lastSun 2:00 0 S
# From Paul Eggert (2000-10-02):
# INMS (2000-09-12) says that, since 1988 at least, Newfoundland switches
# at 00:01 local time. For now, assume it started in 1987.
Rule StJohns 1987 only - Apr Sun>=1 0:01 1:00 D
Rule StJohns 1987 max - Oct lastSun 0:01 0 S
Rule StJohns 1988 only - Apr Sun>=1 0:01 2:00 DD
Rule StJohns 1989 max - Apr Sun>=1 0:01 1:00 D
# St John's has an apostrophe, but Posix file names can't have apostrophes.
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone America/St_Johns -3:30:52 - LMT 1884
-3:30:52 StJohns N%sT 1935 Mar 30
-3:30 StJohns N%sT
# most of east Labrador
# The name `Happy Valley-Goose Bay' is too long; use `Goose Bay'.
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone America/Goose_Bay -4:01:40 - LMT 1884 # Happy Valley-Goose Bay
-3:30:52 StJohns NST 1919
-3:30:52 - NST 1935 Mar 30
-3:30 - NST 1936
-3:30 StJohns N%sT 1966 Mar 15 2:00
-4:00 StJohns A%sT
# west Labrador, New Brunswick, Nova Scotia, Prince Edward I
# From Paul Eggert (1996-06-12):
# Shanks writes that since 1970 most of this region has been like Halifax.
# Many locales did not observe peacetime DST until 1972;
# Glace Bay, NS is the largest that we know of.
# Shanks also writes that Liverpool, NS was the only town in Canada to observe
# DST in 1971 but not 1970; for now we'll assume this is a typo.
# From Paul Eggert (2000-10-02):
# INMS (2000-09-12) says that, since 1988 at least, New Brunswick switches
# at 00:01 local time. FIXME: verify and create a new Zone for this.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Halifax 1916 only - Apr 1 0:00 1:00 D
Rule Halifax 1916 only - Oct 1 0:00 0 S
Rule Halifax 1918 only - Apr 14 2:00 1:00 D
Rule Halifax 1918 only - Oct 31 2:00 0 S
Rule Halifax 1920 only - May 9 0:00 1:00 D
Rule Halifax 1920 only - Aug 29 0:00 0 S
Rule Halifax 1921 only - May 6 0:00 1:00 D
Rule Halifax 1921 1922 - Sep 5 0:00 0 S
Rule Halifax 1922 only - Apr 30 0:00 1:00 D
Rule Halifax 1923 1925 - May Sun>=1 0:00 1:00 D
Rule Halifax 1923 only - Sep 4 0:00 0 S
Rule Halifax 1924 only - Sep 15 0:00 0 S
Rule Halifax 1925 only - Sep 28 0:00 0 S
Rule Halifax 1926 only - May 16 0:00 1:00 D
Rule Halifax 1926 only - Sep 13 0:00 0 S
Rule Halifax 1927 only - May 1 0:00 1:00 D
Rule Halifax 1927 only - Sep 26 0:00 0 S
Rule Halifax 1928 1931 - May Sun>=8 0:00 1:00 D
Rule Halifax 1928 only - Sep 9 0:00 0 S
Rule Halifax 1929 only - Sep 3 0:00 0 S
Rule Halifax 1930 only - Sep 15 0:00 0 S
Rule Halifax 1931 1932 - Sep Mon>=24 0:00 0 S
Rule Halifax 1933 only - Apr 30 0:00 1:00 D
Rule Halifax 1933 only - Oct 2 0:00 0 S
Rule Halifax 1934 only - May 20 0:00 1:00 D
Rule Halifax 1934 only - Sep 16 0:00 0 S
Rule Halifax 1935 only - Jun 2 0:00 1:00 D
Rule Halifax 1935 only - Sep 30 0:00 0 S
Rule Halifax 1936 only - Jun 1 0:00 1:00 D
Rule Halifax 1936 only - Sep 14 0:00 0 S
Rule Halifax 1937 1938 - May Sun>=1 0:00 1:00 D
Rule Halifax 1937 1941 - Sep Mon>=24 0:00 0 S
Rule Halifax 1939 only - May 28 0:00 1:00 D
Rule Halifax 1940 1941 - May Sun>=1 0:00 1:00 D
Rule Halifax 1942 only - Feb 9 2:00 1:00 W
Rule Halifax 1945 1959 - Sep lastSun 2:00 0 S
Rule Halifax 1946 1959 - Apr lastSun 2:00 1:00 D
Rule Halifax 1962 1986 - Apr lastSun 2:00 1:00 D
Rule Halifax 1962 max - Oct lastSun 2:00 0 S
Rule Halifax 1987 max - Apr Sun>=1 2:00 1:00 D
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone America/Halifax -4:14:24 - LMT 1902 Jun 15
-4:00 Halifax A%sT
Zone America/Glace_Bay -3:59:48 - LMT 1902 Jun 15
-4:00 Canada A%sT 1953
-4:00 Halifax A%sT 1954
-4:00 - AST 1972
-4:00 Halifax A%sT
# Ontario, Quebec
# From Paul Eggert (1996-06-12):
# Shanks writes that since 1970 most of this region has been like Montreal.
# Thunder Bay skipped DST in 1973.
# Many smaller locales did not observe peacetime DST until 1974;
# Nipigon (EST) and Rainy River (CST) are the largest that we know of.
# Far west Ontario is like Winnipeg; far east Quebec is like Halifax.
# From Paul Eggert (1997-10-17):
# msb@sq.com writes that an article in the 1997-10-14 Toronto Star
# says that Atikokan, Ontario currently does not observe DST,
# but will vote on 11-10 whether to use EST/EDT.
# He also writes that the
# <a href="http://www.gov.on.ca/MBS/english/publications/statregs/conttext.html">
# Ontario Time Act (1990, Chapter T.9)
# </a>
# says that Ontario east of 90W uses EST/EDT, and west of 90W uses CST/CDT.
# Officially Atikokan is therefore on CST/CDT, and most likely this report
# concerns a non-official time observed as a matter of local practice.
# For what it's worth, Shanks says that Atikokan has agreed with
# Rainy River ever since standard time was introduced.
# From Paul Eggert (2000-10-02):
# Matthews and Vincent (1998) write that Atikokan, Pickle Lake, and
# New Osnaburgh observe CST all year, that Big Trout Lake observes
# CST/CDT, and that Upsala and Shebandowan observe EST/EDT, all in
# violation of the official Ontario rules.
# They also write that Quebec east of the -63 meridian is supposed to
# observe AST, but residents as far east as Natashquan use EST/EDT,
# and residents east of Natashquan use AST.
# We probably need Zones for far east Quebec and for Atikokan,
# but we don't know when their practices started.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Mont 1917 only - Mar 25 2:00 1:00 D
Rule Mont 1917 only - Apr 24 0:00 0 S
Rule Mont 1918 only - Apr 14 2:00 1:00 D
Rule Mont 1918 only - Oct 31 2:00 0 S
Rule Mont 1919 only - Mar 31 2:30 1:00 D
Rule Mont 1919 only - Oct 25 2:30 0 S
Rule Mont 1920 only - May 2 2:30 1:00 D
Rule Mont 1920 only - Oct 3 2:30 0 S
Rule Mont 1921 only - May 1 2:00 1:00 D
Rule Mont 1921 only - Oct 2 2:30 0 S
Rule Mont 1922 only - Apr 30 2:00 1:00 D
Rule Mont 1922 only - Oct 1 2:30 0 S
Rule Mont 1924 only - May 17 2:00 1:00 D
Rule Mont 1924 1926 - Sep lastSun 2:30 0 S
Rule Mont 1925 1926 - May Sun>=1 2:00 1:00 D
Rule Mont 1927 only - May 1 0:00 1:00 D
Rule Mont 1927 1932 - Sep Sun>=25 0:00 0 S
Rule Mont 1928 1931 - Apr Sun>=25 0:00 1:00 D
Rule Mont 1932 only - May 1 0:00 1:00 D
Rule Mont 1933 1940 - Apr Sun>=24 0:00 1:00 D
Rule Mont 1933 only - Oct 1 0:00 0 S
Rule Mont 1934 1939 - Sep Sun>=24 0:00 0 S
Rule Mont 1945 1948 - Sep lastSun 2:00 0 S
Rule Mont 1946 1986 - Apr lastSun 2:00 1:00 D
Rule Mont 1949 1950 - Oct lastSun 2:00 0 S
Rule Mont 1951 1956 - Sep lastSun 2:00 0 S
Rule Mont 1957 max - Oct lastSun 2:00 0 S
Rule Mont 1987 max - Apr Sun>=1 2:00 1:00 D
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone America/Montreal -4:54:16 - LMT 1884
-5:00 Mont E%sT
Zone America/Thunder_Bay -5:57:00 - LMT 1895
-5:00 Canada E%sT 1970
-5:00 Mont E%sT 1973
-5:00 - EST 1974
-5:00 Canada E%sT
Zone America/Nipigon -5:53:04 - LMT 1895
-5:00 Canada E%sT
Zone America/Rainy_River -6:17:56 - LMT 1895
-6:00 Canada C%sT
# Manitoba
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Winn 1916 only - Apr 23 0:00 1:00 D
Rule Winn 1916 only - Sep 17 0:00 0 S
Rule Winn 1918 only - Apr 14 2:00 1:00 D
Rule Winn 1918 only - Oct 31 2:00 0 S
Rule Winn 1937 only - May 16 2:00 1:00 D
Rule Winn 1937 only - Sep 26 2:00 0 S
Rule Winn 1942 only - Feb 9 2:00 1:00 W
Rule Winn 1945 only - Sep lastSun 2:00 0 S
Rule Winn 1946 only - May 12 2:00 1:00 D
Rule Winn 1946 only - Oct 13 2:00 0 S
Rule Winn 1947 1949 - Apr lastSun 2:00 1:00 D
Rule Winn 1947 1949 - Sep lastSun 2:00 0 S
Rule Winn 1950 only - May 1 2:00 1:00 D
Rule Winn 1950 only - Sep 30 2:00 0 S
Rule Winn 1951 1960 - Apr lastSun 2:00 1:00 D
Rule Winn 1951 1958 - Sep lastSun 2:00 0 S
Rule Winn 1959 only - Oct lastSun 2:00 0 S
Rule Winn 1960 only - Sep lastSun 2:00 0 S
Rule Winn 1963 only - Apr lastSun 2:00 1:00 D
Rule Winn 1963 only - Sep 22 2:00 0 S
Rule Winn 1966 1986 - Apr lastSun 2:00 1:00 D
Rule Winn 1966 1986 - Oct lastSun 2:00 0 S
Rule Winn 1987 max - Apr Sun>=1 2:00 1:00 D
# From Paul Eggert (2000-10-02):
# INMS (2000-09-12) says that, since 1988 at least, Manitoba switches from
# DST at 03:00 local time. For now, assume it started in 1987.
Rule Winn 1987 max - Oct lastSun 2:00s 0 S
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone America/Winnipeg -6:28:36 - LMT 1887 Jul 16
-6:00 Winn C%sT
# Saskatchewan
# From Paul Eggert (2000-10-02):
# Shanks writes that since 1970 most of this region has been like Regina.
# Some western towns (e.g. Swift Current) switched from MST/MDT to CST in 1972.
# Other western towns (e.g. Lloydminster) are like Edmonton.
# Matthews and Vincent (1998) write that Denare Beach and Creighton
# are like Winnipeg, in violation of Saskatchewan law.
# From W. Jones <jones@skdad.usask.ca> (1992-11-06):
# The. . .below is based on information I got from our law library, the
# provincial archives, and the provincial Community Services department.
# A precise history would require digging through newspaper archives, and
# since you didn't say what you wanted, I didn't bother.
#
# Saskatchewan is split by a time zone meridian (105W) and over the years
# the boundary became pretty ragged as communities near it reevaluated
# their affiliations in one direction or the other. In 1965 a provincial
# referendum favoured legislating common time practices.
#
# On 15 April 1966 the Time Act (c. T-14, Revised Statutes of
# Saskatchewan 1978) was proclaimed, and established that the eastern
# part of Saskatchewan would use CST year round, that districts in
# northwest Saskatchewan would by default follow CST but could opt to
# follow Mountain Time rules (thus 1 hour difference in the winter and
# zero in the summer), and that districts in southwest Saskatchewan would
# by default follow MT but could opt to follow CST.
#
# It took a few years for the dust to settle (I know one story of a town
# on one time zone having its school in another, such that a mom had to
# serve her family lunch in two shifts), but presently it seems that only
# a few towns on the border with Alberta (e.g. Lloydminster) follow MT
# rules any more; all other districts appear to have used CST year round
# since sometime in the 1960s.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Regina 1918 only - Apr 14 2:00 1:00 D
Rule Regina 1918 only - Oct 31 2:00 0 S
Rule Regina 1930 1934 - May Sun>=1 0:00 1:00 D
Rule Regina 1930 1934 - Oct Sun>=1 0:00 0 S
Rule Regina 1937 1941 - Apr Sun>=8 0:00 1:00 D
Rule Regina 1937 only - Oct Sun>=8 0:00 0 S
Rule Regina 1938 only - Oct Sun>=1 0:00 0 S
Rule Regina 1939 1941 - Oct Sun>=8 0:00 0 S
Rule Regina 1942 only - Feb 9 2:00 1:00 W
Rule Regina 1945 only - Sep lastSun 2:00 0 S
Rule Regina 1946 only - Apr Sun>=8 2:00 1:00 D
Rule Regina 1946 only - Oct Sun>=8 2:00 0 S
Rule Regina 1947 1959 - Apr lastSun 2:00 1:00 D
Rule Regina 1947 1958 - Sep lastSun 2:00 0 S
Rule Regina 1959 only - Oct lastSun 2:00 0 S
#
Rule Swift 1957 only - Apr lastSun 2:00 1:00 D
Rule Swift 1957 only - Oct lastSun 2:00 0 S
Rule Swift 1959 1961 - Apr lastSun 2:00 1:00 D
Rule Swift 1959 only - Oct lastSun 2:00 0 S
Rule Swift 1960 1961 - Sep lastSun 2:00 0 S
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone America/Regina -6:58:36 - LMT 1905 Sep
-7:00 Regina M%sT 1960 Apr lastSun 2:00
-6:00 - CST
Zone America/Swift_Current -7:11:20 - LMT 1905 Sep
-7:00 Canada M%sT 1946 Apr lastSun 2:00
-7:00 Regina M%sT 1950
-7:00 Swift M%sT 1972 Apr lastSun 2:00
-6:00 - CST
# Alberta
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Edm 1918 1919 - Apr Sun>=8 2:00 1:00 D
Rule Edm 1918 only - Oct 31 2:00 0 S
Rule Edm 1919 only - May 27 2:00 0 S
Rule Edm 1920 1923 - Apr lastSun 2:00 1:00 D
Rule Edm 1920 only - Oct lastSun 2:00 0 S
Rule Edm 1921 1923 - Sep lastSun 2:00 0 S
Rule Edm 1942 only - Feb 9 2:00 1:00 W
Rule Edm 1945 only - Sep lastSun 2:00 0 S
Rule Edm 1947 only - Apr lastSun 2:00 1:00 D
Rule Edm 1947 only - Sep lastSun 2:00 0 S
Rule Edm 1967 only - Apr lastSun 2:00 1:00 D
Rule Edm 1967 only - Oct lastSun 2:00 0 S
Rule Edm 1969 only - Apr lastSun 2:00 1:00 D
Rule Edm 1969 only - Oct lastSun 2:00 0 S
Rule Edm 1972 1986 - Apr lastSun 2:00 1:00 D
Rule Edm 1972 max - Oct lastSun 2:00 0 S
Rule Edm 1987 max - Apr Sun>=1 2:00 1:00 D
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone America/Edmonton -7:33:52 - LMT 1906 Sep
-7:00 Edm M%sT
# British Columbia
# From Paul Eggert (2000-10-02):
# Shanks writes that since 1970 most of this region has been like Vancouver.
# Dawson Creek uses MST. Much of east BC is like Edmonton.
# Matthews and Vincent (1998) write that Creston is like Dawson Creek.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Vanc 1918 only - Apr 14 2:00 1:00 D
Rule Vanc 1918 only - Oct 31 2:00 0 S
Rule Vanc 1942 only - Feb 9 2:00 1:00 W
Rule Vanc 1945 only - Sep 30 2:00 0 S
Rule Vanc 1946 1986 - Apr lastSun 2:00 1:00 D
Rule Vanc 1946 only - Oct 13 2:00 0 S
Rule Vanc 1947 1961 - Sep lastSun 2:00 0 S
Rule Vanc 1962 max - Oct lastSun 2:00 0 S
Rule Vanc 1987 max - Apr Sun>=1 2:00 1:00 D
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone America/Vancouver -8:12:28 - LMT 1884
-8:00 Vanc P%sT
Zone America/Dawson_Creek -8:00:56 - LMT 1884
-8:00 Canada P%sT 1947
-8:00 Vanc P%sT 1972 Aug 30 2:00
-7:00 - MST
# Northwest Territories, Nunavut, Yukon
# From Paul Eggert (1999-10-29):
# Dawson switched to PST in 1973. Inuvik switched to MST in 1979.
# Mathew Englander <mathew@io.org> (1996-10-07) gives the following refs:
# * 1967. Paragraph 28(34)(g) of the Interpretation Act, S.C. 1967-68,
# c. 7 defines Yukon standard time as UTC-9. This is still valid;
# see Interpretation Act, R.S.C. 1985, c. I-21, s. 35(1).
# * C.O. 1973/214 switched Yukon to PST on 1973-10-28 00:00.
# * O.I.C. 1980/02 established DST.
# * O.I.C. 1987/056 changed DST to Apr firstSun 2:00 to Oct lastSun 2:00.
# Shanks says Yukon's 1973-10-28 switch was at 2:00; go with Englander.
# From Rives McDow (1999-09-04):
# Nunavut ... moved ... to incorporate the whole territory into one time zone.
# <a href="http://www.nunatsiaq.com/nunavut/nvt90903_13.html">
# Nunavut moves to single time zone Oct. 31
# </a>
#
# From Antoine Leca (1999-09-06):
# We then need to create a new timezone for the Kitikmeot region of Nunavut
# to differentiate it from the Yellowknife region.
# From Paul Eggert (1999-09-20):
# <a href="http://www.nunavut.com/basicfacts/english/basicfacts_1territory.html">
# Basic Facts: The New Territory
# </a> (1999) reports that Pangnirtung operates on Eastern time,
# and that Coral Harbour does not observe DST. We don't know when
# Pangnirtung switched to Eastern time; we'll guess 1995.
# We'll ignore the claim about Coral Harbour for now,
# since we have no further info.
# From Rives McDow (1999-11-08):
# On October 31, when the rest of Nunavut went to Central time,
# Pangnirtung wobbled. Here is the result of their wobble:
#
# The following businesses and organizations in Pangnirtung use Central Time:
#
# First Air, Power Corp, Nunavut Construction, Health Center, RCMP,
# Eastern Arctic National Parks, A & D Specialist
#
# The following businesses and organizations in Pangnirtung use Eastern Time:
#
# Hamlet office, All other businesses, Both schools, Airport operator
#
# This has made for an interesting situation there, which warranted the news.
# No one there that I spoke with seems concerned, or has plans to
# change the local methods of keeping time, as it evidently does not
# really interfere with any activities or make things difficult locally.
# They plan to celebrate New Year's turn-over twice, one hour apart,
# so it appears that the situation will last at least that long.
# The Nunavut Intergovernmental Affairs hopes that they will "come to
# their senses", but the locals evidently don't see any problem with
# the current state of affairs.
# From Michaela Rodrigue, writing in the
# <a href="http://www.nunatsiaq.com/archives/nunavut991130/nvt91119_17.html">
# Nunatsiaq News (1999-11-19)</a>:
# Clyde River, Pangnirtung and Sanikiluaq now operate with two time zones,
# central - or Nunavut time - for government offices, and eastern time
# for municipal offices and schools.... Igloolik [was similar but then]
# made the switch to central time on Saturday, Nov. 6.
# From Paul Eggert (2000-10-02):
# Matthews and Vincent (1998) say the following, but we lack histories
# for these potential new Zones.
#
# The Canadian Forces station at Alert uses Eastern Time while the
# handful of residents at the Eureka weather station [in the Central
# zone] skip daylight savings. Baffin Island, which is crossed by the
# Central, Eastern and Atlantic Time zones only uses Eastern Time.
# Gjoa Haven, Taloyoak and Pelly Bay all use Mountain instead of
# Central Time and Southampton Island [in the Central zone] is not
# required to use daylight savings.
# From
# <a href="http://www.nunatsiaq.com/archives/nunavut001130/nvt21110_02.html">
# Nunavut now has two time zones
# </a> (2000-11-10):
# The Nunavut government would allow its employees in Kugluktuk and
# Cambridge Bay to operate on central time year-round, putting them
# one hour behind the rest of Nunavut for six months during the winter.
# At the end of October the two communities had rebelled against
# Nunavut's unified time zone, refusing to shift to eastern time with
# the rest of the territory for the winter. Cambridge Bay remained on
# central time, while Kugluktuk, even farther west, reverted to
# mountain time, which they had used before the advent of Nunavut's
# unified time zone in 1999.
#
# From Rives McDow (2001-01-20), quoting the Nunavut government:
# The preceding decision came into effect at midnight, Saturday Nov 4, 2000.
# From Paul Eggert (2000-12-04):
# Let's just keep track of the official times for now.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule NT_YK 1918 only - Apr 14 2:00 1:00 D
Rule NT_YK 1918 only - Oct 27 2:00 0 S
Rule NT_YK 1919 only - May 25 2:00 1:00 D
Rule NT_YK 1919 only - Nov 1 0:00 0 S
Rule NT_YK 1942 only - Feb 9 2:00 1:00 W
Rule NT_YK 1945 only - Sep 30 2:00 0 S
Rule NT_YK 1965 only - Apr lastSun 0:00 2:00 DD
Rule NT_YK 1965 only - Oct lastSun 2:00 0 S
Rule NT_YK 1980 1986 - Apr lastSun 2:00 1:00 D
Rule NT_YK 1980 max - Oct lastSun 2:00 0 S
Rule NT_YK 1987 max - Apr Sun>=1 2:00 1:00 D
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone America/Pangnirtung -4:22:56 - LMT 1884
-4:00 NT_YK A%sT 1995 Apr Sun>=1 2:00
-5:00 Canada E%sT 1999 Oct 31 2:00
-6:00 Canada C%sT 2000 Oct 29 2:00
-5:00 - EST
Zone America/Iqaluit -4:33:52 - LMT 1884 # Frobisher Bay before 1987
-5:00 NT_YK E%sT 1999 Oct 31 2:00
-6:00 Canada C%sT 2000 Oct 29 2:00
-5:00 - EST
Zone America/Rankin_Inlet -6:08:40 - LMT 1884
-6:00 NT_YK C%sT 2000 Oct 29 2:00
-5:00 - EST
Zone America/Cambridge_Bay -7:00:20 - LMT 1884
-7:00 NT_YK M%sT 1999 Oct 31 2:00
-6:00 Canada C%sT 2000 Oct 29 2:00
-5:00 - EST 2000 Nov 5 0:00
-6:00 Canada C%sT
Zone America/Yellowknife -7:37:24 - LMT 1884
-7:00 NT_YK M%sT
Zone America/Inuvik -8:54:00 - LMT 1884
-8:00 NT_YK P%sT 1979 Apr lastSun 2:00
-7:00 NT_YK M%sT
Zone America/Whitehorse -9:00:12 - LMT 1900 Aug 20
-9:00 NT_YK Y%sT 1966 Jul 1 2:00
-8:00 NT_YK P%sT
Zone America/Dawson -9:17:40 - LMT 1900 Aug 20
-9:00 NT_YK Y%sT 1973 Oct 28 0:00
-8:00 NT_YK P%sT
###############################################################################
# Mexico
# From Paul Eggert (2001-03-05):
# The Investigation and Analysis Service of the
# Mexican Library of Congress (MLoC) has published a
# <a href="http://www.cddhcu.gob.mx/bibliot/publica/inveyana/polisoc/horver/">
# history of Mexican local time (in Spanish)
# </a>.
#
# Here are the discrepancies between Shanks and the MLoC.
# (In all cases we go with the MLoC.)
# Shanks reports that Baja was at -8:00 in 1922/1923.
# Shanks says the 1930 transition in Baja was 1930-11-16.
# Shanks reports no DST during summer 1931.
# Shanks reports a transition at 1032-03-30 23:00, not 1932-04-01.
# Shanks does not report transitions for Baja in 1945 or 1948.
# Shanks reports southern Mexico transitions on 1981-12-01, not 12-23.
# Shanks says Quintana Roo switched to -6:00 on 1982-12-02, and to -5:00
# on 1997-10-26 at 02:00.
# From Gwillim Law (2001-02-20):
# There are some other discrepancies between the Decrees page and the
# tz database. I think they can best be explained by supposing that
# the researchers who prepared the Decrees page failed to find some of
# the relevant documents.
# From Paul Eggert (2000-07-26):
# Shanks gives 1942-04-01 instead of 1942-04-24, and omits the 1981
# and 1988 DST experiments. Go with spin.com.mx.
# From Alan Perry <alan.perry@eng.sun.com> (1996-02-15):
# A guy from our Mexico subsidiary finally found the Presidential Decree
# outlining the timezone changes in Mexico.
#
# ------------- Begin Forwarded Message -------------
#
# I finally got my hands on the Official Presidential Decree that sets up the
# rules for the DST changes. The rules are:
#
# 1. The country is divided in 3 timezones:
# - Baja California Norte (the Mexico/BajaNorte TZ)
# - Baja California Sur, Nayarit, Sinaloa and Sonora (the Mexico/BajaSur TZ)
# - The rest of the country (the Mexico/General TZ)
#
# 2. From the first Sunday in April at 2:00 AM to the last Sunday in October
# at 2:00 AM, the times in each zone are as follows:
# BajaNorte: GMT+7
# BajaSur: GMT+6
# General: GMT+5
#
# 3. The rest of the year, the times are as follows:
# BajaNorte: GMT+8
# BajaSur: GMT+7
# General: GMT+6
#
# The Decree was published in Mexico's Official Newspaper on January 4th.
#
# -------------- End Forwarded Message --------------
# From Paul Eggert (1996-06-12):
# For an English translation of the decree, see
# <a href="http://mexico-travel.com/extra/timezone_eng.html">
# ``Diario Oficial: Time Zone Changeover'' (1996-01-04).
# </a>
# From Rives McDow (1998-10-08):
# The State of Quintana Roo has reverted back to central STD and DST times
# (i.e. UTC -0600 and -0500 as of 1998-08-02).
# From Rives McDow (2000-01-10):
# Effective April 4, 1999 at 2:00 AM local time, Sonora changed to the time
# zone 5 hours from the International Date Line, and will not observe daylight
# savings time so as to stay on the same time zone as the southern part of
# Arizona year round.
# From Jesper Norgaard, translating
# <http://www.reforma.com/nacional/articulo/064327/> (2001-01-17):
# In Oaxaca, the 55.000 teachers from the Section 22 of the National
# Syndicate of Education Workers, refuse to apply daylight saving each
# year, so that the more than 10,000 schools work at normal hour the
# whole year.
# From Gwillim Law (2001-01-19):
# <http://www.reforma.com/negocios_y_dinero/articulo/064481/> ... says
# (translated):...
# January 17, 2000 - The Energy Secretary, Ernesto Martens, announced
# that Summer Time will be reduced from seven to five months, starting
# this year....
# <http://www.publico.com.mx/scripts/texto3.asp?action=pagina&pag=21&pos=p&secc=naci&date=01/17/2001>
# [translated], says "summer time will ... take effect on the first Sunday
# in May, and end on the last Sunday of September.
# From Arthur David Olson (2001-01-25):
# The 2001-01-24 traditional Washington Post contained the page one
# story "Timely Issue Divides Mexicans."...
# http://www.washingtonpost.com/wp-dyn/articles/A37383-2001Jan23.html
# ... Mexico City Mayor Lopez Obrador "...is threatening to keep
# Mexico City and its 20 million residents on a different time than
# the rest of the country..." In particular, Lopez Obrador would abolish
# observation of Daylight Saving Time.
# <a href="http://www.conae.gob.mx/ahorro/decretohorver2001.html#decre">
# Official statute published by the Energy Department
# </a> (2001-02-01) shows Baja and Chihauhua as still using US DST rules,
# and Sonora with no DST. This was reported by Jesper Norgaard (2001-02-03).
# From Paul Eggert (2001-03-03):
#
# <a href="http://www.latimes.com/news/nation/20010303/t000018766.html">
# James F. Smith writes in today's LA Times
# </a>
# * Sonora will continue to observe standard time.
# * Border states including Baja California, Chihuahua, and Nuevo Leon
# will use US rules,
# * Last week Mexico City's mayor Andres Manuel Lopez Obrador decreed that
# the Federal District will not adopt DST.
# * 4 of 16 district leaders announced they'll ignore the decree.
# * The decree does not affect federal-controlled facilities including
# the airport, banks, hospitals, and schools.
#
# For now we'll assume that the Federal District will bow to federal rules
# and that border states and Durango will stick with US rules.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Mexico 1939 only - Feb 5 0:00 1:00 D
Rule Mexico 1939 only - Jun 25 0:00 0 S
Rule Mexico 1940 only - Dec 9 0:00 1:00 D
Rule Mexico 1941 only - Apr 1 0:00 0 S
Rule Mexico 1943 only - Dec 16 0:00 1:00 W
Rule Mexico 1944 only - May 1 0:00 0 S
Rule Mexico 1950 only - Feb 12 0:00 1:00 D
Rule Mexico 1950 only - Jul 30 0:00 0 S
Rule Mexico 1996 2000 - Apr Sun>=1 2:00 1:00 D
Rule Mexico 1996 2000 - Oct lastSun 2:00 0 S
Rule Mexico 2001 max - May Sun>=1 2:00 1:00 D
Rule Mexico 2001 max - Sep lastSun 2:00 0 S
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
# Quintana Roo
Zone America/Cancun -5:47:04 - LMT 1922 Jan 1 0:12:56
-6:00 - CST 1981 Dec 23
-5:00 Mexico E%sT 1998 Aug 2 2:00
-6:00 Mexico C%sT
# Campeche, Yucatan
Zone America/Merida -5:58:28 - LMT 1922 Jan 1 0:01:32
-6:00 - CST 1981 Dec 23
-5:00 - EST 1982 Dec 2
-6:00 Mexico C%sT
# Coahuila, Durango, Nuevo Leon, Tamaulipas
Zone America/Monterrey -6:41:16 - LMT 1921 Dec 31 23:18:44
-6:00 - CST 1988
-6:00 US C%sT 1989
-6:00 Mexico C%sT 2001
-6:00 US C%sT
# Central Mexico
Zone America/Mexico_City -6:36:36 - LMT 1922 Jan 1 0:23:24
-7:00 - MST 1927 Jun 10 23:00
-6:00 - CST 1930 Nov 15
-7:00 - MST 1931 May 1 23:00
-6:00 - CST 1931 Oct
-7:00 - MST 1932 Apr 1
-6:00 Mexico C%sT
# Chihuahua
Zone America/Chihuahua -7:04:20 - LMT 1921 Dec 31 23:55:40
-7:00 - MST 1927 Jun 10 23:00
-6:00 - CST 1930 Nov 15
-7:00 - MST 1931 May 1 23:00
-6:00 - CST 1931 Oct
-7:00 - MST 1932 Apr 1
-6:00 - CST 1996
-6:00 Mexico C%sT 1998
-6:00 - CST 1998 Apr Sun>=1 3:00
-7:00 Mexico M%sT 2001
-7:00 US M%sT
# Sonora
Zone America/Hermosillo -7:23:52 - LMT 1921 Dec 31 23:36:08
-7:00 - MST 1927 Jun 10 23:00
-6:00 - CST 1930 Nov 15
-7:00 - MST 1931 May 1 23:00
-6:00 - CST 1931 Oct
-7:00 - MST 1932 Apr 1
-6:00 - CST 1942 Apr 24
-7:00 - MST 1949 Jan 14
-8:00 - PST 1970
-7:00 Mexico M%sT 1999
-7:00 - MST
# Baja California Sur, Nayarit, Sinaloa
Zone America/Mazatlan -7:05:40 - LMT 1921 Dec 31 23:54:20
-7:00 - MST 1927 Jun 10 23:00
-6:00 - CST 1930 Nov 15
-7:00 - MST 1931 May 1 23:00
-6:00 - CST 1931 Oct
-7:00 - MST 1932 Apr 1
-6:00 - CST 1942 Apr 24
-7:00 - MST 1949 Jan 14
-8:00 - PST 1970
-7:00 Mexico M%sT
# Baja California
Zone America/Tijuana -7:48:04 - LMT 1922 Jan 1 0:11:56
-7:00 - MST 1924
-8:00 - PST 1927 Jun 10 23:00
-7:00 - MST 1930 Nov 15
-8:00 - PST 1931 Apr 1
-8:00 1:00 PDT 1931 Sep 30
-8:00 - PST 1942 Apr 24
-8:00 1:00 PWT 1945 Nov 12
-8:00 - PST 1948 Apr 5
-8:00 1:00 PDT 1949 Jan 14
-8:00 - PST 1954
-8:00 CA P%sT 1961
-8:00 - PST 1976
-8:00 US P%sT 1996
-8:00 Mexico P%sT 2001
-8:00 US P%sT
# From Paul Eggert (2001-03-05):
# Formerly there was an America/Ensenada zone, which differed from
# America/Tijuana only in that it did not observe DST from 1976
# through 1995. This was as per Shanks. However, Guy Harris reports
# that the 1987 OAG says "Only Ensenada, Mexicale, San Felipe and
# Tijuana observe DST," which contradicts Shanks but does imply that
# DST-observance was a town-by-town matter back then. This concerns
# data after 1970 so most likely there should be at least one Zone
# other than America/Tijuana for Baja, but it's not clear yet what its
# name or contents should be.
#
# Revillagigedo Is
# no information
###############################################################################
# Anguilla
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone America/Anguilla -4:12:16 - LMT 1912 Mar 2
-4:00 - AST
# Antigua and Barbuda
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone America/Antigua -4:07:12 - LMT 1912 Mar 2
-5:00 - EST 1951
-4:00 - AST
# Bahamas
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Bahamas 1964 max - Oct lastSun 2:00 0 S
Rule Bahamas 1964 1986 - Apr lastSun 2:00 1:00 D
Rule Bahamas 1987 max - Apr Sun>=1 2:00 1:00 D
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone America/Nassau -5:09:24 - LMT 1912 Mar 2
-5:00 Bahamas E%sT
# Barbados
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Barb 1977 only - Jun 12 2:00 1:00 D
Rule Barb 1977 1978 - Oct Sun>=1 2:00 0 S
Rule Barb 1978 1980 - Apr Sun>=15 2:00 1:00 D
Rule Barb 1979 only - Sep 30 2:00 0 S
Rule Barb 1980 only - Sep 25 2:00 0 S
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone America/Barbados -3:58:28 - LMT 1924 # Bridgetown
-3:58:28 - BMT 1932 # Bridgetown Mean Time
-4:00 Barb A%sT
# Belize
# Whitman entirely disagrees with Shanks; go with Shanks.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Belize 1918 1942 - Oct Sun>=2 0:00 0:30 HD
Rule Belize 1919 1943 - Feb Sun>=9 0:00 0 S
Rule Belize 1973 only - Dec 5 0:00 1:00 D
Rule Belize 1974 only - Feb 9 0:00 0 S
Rule Belize 1982 only - Dec 18 0:00 1:00 D
Rule Belize 1983 only - Feb 12 0:00 0 S
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone America/Belize -5:52:48 - LMT 1912 Apr
-6:00 Belize C%sT
# Bermuda
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone Atlantic/Bermuda -4:19:04 - LMT 1930 Jan 1 2:00 # Hamilton
-4:00 - AST 1974 Apr 28 2:00
-4:00 Bahamas A%sT
# Cayman Is
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone America/Cayman -5:25:32 - LMT 1890 # Georgetown
-5:07:12 - KMT 1912 Feb # Kingston Mean Time
-5:00 - EST
# Costa Rica
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule CR 1979 1980 - Feb lastSun 0:00 1:00 D
Rule CR 1979 1980 - Jun Sun>=1 0:00 0 S
Rule CR 1991 1992 - Jan Sat>=15 0:00 1:00 D
# IATA SSIM (1991-09) says the following was at 1:00; go with Shanks.
Rule CR 1991 only - Jul 1 0:00 0 S
Rule CR 1992 only - Mar 15 0:00 0 S
# There are too many San Joses elsewhere, so we'll use `Costa Rica'.
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone America/Costa_Rica -5:36:20 - LMT 1890 # San Jose
-5:36:20 - SJMT 1921 Jan 15 # San Jose Mean Time
-6:00 CR C%sT
# Coco
# no information; probably like America/Costa_Rica
# Cuba
# From Arthur David Olson (1999-03-29):
# The 1999-03-28 exhibition baseball game held in Havana, Cuba, between
# the Cuban National Team and the Baltimore Orioles was carried live on
# the Orioles Radio Network, including affiliate WTOP in Washington, DC.
# During the game, play-by-play announcer Jim Hunter noted that
# "We'll be losing two hours of sleep...Cuba switched to Daylight Saving
# Time today." (The "two hour" remark referred to losing one hour of
# sleep on 1999-03-28--when the announcers were in Cuba as it switched
# to DST--and one more hour on 1999-04-04--when the announcers will have
# returned to Baltimore, which switches on that date.)
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Cuba 1928 only - Jun 10 0:00 1:00 D
Rule Cuba 1928 only - Oct 10 0:00 0 S
Rule Cuba 1940 1942 - Jun Sun>=1 0:00 1:00 D
Rule Cuba 1940 1942 - Sep Sun>=1 0:00 0 S
Rule Cuba 1945 1946 - Jun Sun>=1 0:00 1:00 D
Rule Cuba 1945 1946 - Sep Sun>=1 0:00 0 S
Rule Cuba 1965 only - Jun 1 0:00 1:00 D
Rule Cuba 1965 only - Sep 30 0:00 0 S
Rule Cuba 1966 only - May 29 0:00 1:00 D
Rule Cuba 1966 only - Oct 2 0:00 0 S
Rule Cuba 1967 only - Apr 8 0:00 1:00 D
Rule Cuba 1967 1968 - Sep Sun>=8 0:00 0 S
Rule Cuba 1968 only - Apr 14 0:00 1:00 D
Rule Cuba 1969 1977 - Apr lastSun 0:00 1:00 D
Rule Cuba 1969 1971 - Oct lastSun 0:00 0 S
Rule Cuba 1972 1974 - Oct 8 0:00 0 S
Rule Cuba 1975 1977 - Oct lastSun 0:00 0 S
Rule Cuba 1978 only - May 7 0:00 1:00 D
Rule Cuba 1978 1990 - Oct Sun>=8 0:00 0 S
Rule Cuba 1979 1980 - Mar Sun>=15 0:00 1:00 D
Rule Cuba 1981 1985 - May Sun>=5 0:00 1:00 D
Rule Cuba 1986 1989 - Mar Sun>=14 0:00 1:00 D
Rule Cuba 1990 1997 - Apr Sun>=1 0:00 1:00 D
Rule Cuba 1991 1995 - Oct Sun>=8 0:00s 0 S
Rule Cuba 1996 only - Oct 6 0:00s 0 S
Rule Cuba 1997 only - Oct 12 0:00s 0 S
Rule Cuba 1998 1999 - Mar lastSun 0:00s 1:00 D
Rule Cuba 1998 max - Oct lastSun 0:00s 0 S
Rule Cuba 2000 max - Apr Sun>=1 0:00s 1:00 D
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone America/Havana -5:29:28 - LMT 1890
-5:29:36 - HMT 1925 Jul 19 12:00 # Havana MT
-5:00 Cuba C%sT
# Dominica
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone America/Dominica -4:05:36 - LMT 1911 Jul 1 0:01 # Roseau
-4:00 - AST
# Dominican Republic
# From Steffen Thorsen (2000-10-30):
# Enrique Morales reported to me that the Dominican Republic has changed the
# time zone to Eastern Standard Time as of Sunday 29 at 2 am....
# http://www.listin.com.do/antes/261000/republica/princi.html
# From Paul Eggert (2000-12-04):
# That URL (2000-10-26, in Spanish) says they planned to use US-style DST.
# From Rives McDow (2000-12-01):
# Dominican Republic changed its mind and presidential decree on Tuesday,
# November 28, 2000, with a new decree. On Sunday, December 3 at 1:00 AM the
# Dominican Republic will be reverting to 8 hours from the International Date
# Line, and will not be using DST in the foreseeable future. The reason they
# decided to use DST was to be in synch with Puerto Rico, who was also going
# to implement DST. When Puerto Rico didn't implement DST, the president
# decided to revert.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule DR 1966 only - Oct 30 0:00 1:00 D
Rule DR 1967 only - Feb 28 0:00 0 S
Rule DR 1969 1973 - Oct lastSun 0:00 0:30 HD
Rule DR 1970 only - Feb 21 0:00 0 S
Rule DR 1971 only - Jan 20 0:00 0 S
Rule DR 1972 1974 - Jan 21 0:00 0 S
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone America/Santo_Domingo -4:39:36 - LMT 1890
-4:40 - SDMT 1933 Apr 1 12:00 # S. Dom. MT
-5:00 DR E%sT 1974 Oct 27
-4:00 - AST 2000 Oct 29 02:00
-5:00 US E%sT 2000 Dec 3 01:00
-4:00 - AST
# El Salvador
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Salv 1987 1988 - May Sun>=1 0:00 1:00 D
Rule Salv 1987 1988 - Sep lastSun 0:00 0 S
# There are too many San Salvadors elsewhere, so we'll use `El Salvador'.
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone America/El_Salvador -5:56:48 - LMT 1921 # San Salvador
-6:00 Salv C%sT
# Grenada
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone America/Grenada -4:07:00 - LMT 1911 Jul # St George's
-4:00 - AST
# Guadeloupe
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone America/Guadeloupe -4:06:08 - LMT 1911 Jun 8 # Pointe a Pitre
-4:00 - AST
# Guatemala
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Guat 1973 only - Nov 25 0:00 1:00 D
Rule Guat 1974 only - Feb 24 0:00 0 S
Rule Guat 1983 only - May 21 0:00 1:00 D
Rule Guat 1983 only - Sep 22 0:00 0 S
Rule Guat 1991 only - Mar 23 0:00 1:00 D
Rule Guat 1991 only - Sep 7 0:00 0 S
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone America/Guatemala -6:02:04 - LMT 1918 Oct 5
-6:00 Guat C%sT
# Haiti
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Haiti 1983 only - May 8 0:00 1:00 D
Rule Haiti 1984 1987 - Apr lastSun 0:00 1:00 D
Rule Haiti 1983 1987 - Oct lastSun 0:00 0 S
# Shanks says AT is 2:00, but IATA SSIM (1991/1997) says 1:00s. Go with IATA.
Rule Haiti 1988 1997 - Apr Sun>=1 1:00s 1:00 D
Rule Haiti 1988 1997 - Oct lastSun 1:00s 0 S
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone America/Port-au-Prince -4:49:20 - LMT 1890
-4:49 - PPMT 1917 Jan 24 12:00 # P-a-P MT
-5:00 Haiti E%sT
# Honduras
# Shanks says 1921 Jan 1; go with Whitman's more precise Apr 1.
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone America/Tegucigalpa -5:48:52 - LMT 1921 Apr
-6:00 Salv C%sT
#
# Great Swan I ceded by US to Honduras in 1972
# Jamaica
# From Bob Devine (1988-01-28):
# Follows US rules.
# From U. S. Naval Observatory (1989-01-19):
# JAMAICA 5 H BEHIND UTC
# From Shanks:
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone America/Jamaica -5:07:12 - LMT 1890 # Kingston
-5:07:12 - KMT 1912 Feb # Kingston Mean Time
-5:00 - EST 1974 Apr 28 2:00
-5:00 US E%sT 1984
-5:00 - EST
# Martinique
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone America/Martinique -4:04:20 - LMT 1890 # Fort-de-France
-4:04 - FFMT 1911 May # Fort-de-France MT
-4:00 - AST 1980 Apr 6
-4:00 1:00 ADT 1980 Sep 28
-4:00 - AST
# Montserrat
# From Paul Eggert (1997-08-31):
# Recent volcanic eruptions have forced evacuation of Plymouth, the capital.
# Luckily, Olveston, the current de facto capital, has the same longitude.
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone America/Montserrat -4:08:52 - LMT 1911 Jul 1 0:01 # Olveston
-4:00 - AST
# Nicaragua
#
# From Steffen Thorsen (1998-12-29):
# Nicaragua seems to be back at -6:00 but I have not been able to find when
# they changed from -5:00.
#
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Nic 1979 1980 - Mar Sun>=16 0:00 1:00 D
Rule Nic 1979 1980 - Jun Mon>=23 0:00 0 S
Rule Nic 1992 only - Jan 1 4:00 1:00 D
Rule Nic 1992 only - Sep 24 0:00 0 S
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone America/Managua -5:45:08 - LMT 1890
-5:45 - MMT 1934 Jun 23 # Managua Mean Time
-6:00 - CST 1973 May
-5:00 - EST 1975 Feb 16
-6:00 Nic C%sT 1993 Jan 1 4:00
-5:00 - EST 1998 Dec
-6:00 - CST
# Panama
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone America/Panama -5:18:08 - LMT 1890
-5:20 - PMT 1908 Apr 22 # Panama Mean Time
-5:00 - EST
# Puerto Rico
# There are too many San Juans elsewhere, so we'll use `Puerto_Rico'.
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone America/Puerto_Rico -4:24:25 - LMT 1899 Mar 28 12:00 # San Juan
-4:00 - AST 1942 May 3
-4:00 1:00 AWT 1945 Sep 30 2:00
-4:00 - AST
# St Kitts-Nevis
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone America/St_Kitts -4:10:52 - LMT 1912 Mar 2 # Basseterre
-4:00 - AST
# St Lucia
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone America/St_Lucia -4:04:00 - LMT 1890 # Castries
-4:04 - CMT 1912 # Castries Mean Time
-4:00 - AST
# St Pierre and Miquelon
# There are too many St Pierres elsewhere, so we'll use `Miquelon'.
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone America/Miquelon -3:44:40 - LMT 1911 May 15 # St Pierre
-4:00 - AST 1980 May
-3:00 Mont PM%sT # Pierre & Miquelon Time
# St Vincent and the Grenadines
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone America/St_Vincent -4:04:56 - LMT 1890 # Kingstown
-4:04:56 - KMT 1912 # Kingstown Mean Time
-4:00 - AST
# Turks and Caicos
# From Paul Eggert (1998-08-06):
# Shanks says they use US DST rules, but IATA SSIM (1991/1998)
# says they switch at midnight. Go with IATA SSIM.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule TC 1979 1986 - Apr lastSun 0:00 1:00 D
Rule TC 1979 max - Oct lastSun 0:00 0 S
Rule TC 1987 max - Apr Sun>=1 0:00 1:00 D
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone America/Grand_Turk -4:44:32 - LMT 1890
-5:07:12 - KMT 1912 Feb # Kingston Mean Time
-5:00 TC E%sT
# British Virgin Is
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone America/Tortola -4:18:28 - LMT 1911 Jul # Road Town
-4:00 - AST
# Virgin Is
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone America/St_Thomas -4:19:44 - LMT 1911 Jul # Charlotte Amalie
-4:00 - AST
|