1 News for the tz database
3 Release 2021a - 2021-01-24 10:54:57 -0800
5 Changes to future timestamps
7 South Sudan changes from +03 to +02 on 2021-02-01 at 00:00.
8 (Thanks to Steffen Thorsen.)
11 Release 2020f - 2020-12-29 00:17:46 -0800
13 Change to build procedure
15 'make rearguard_tarballs' no longer generates a bad rearguard.zi,
16 fixing a 2020e bug. (Problem reported by Deborah Goldsmith.)
19 Release 2020e - 2020-12-22 15:14:34 -0800
22 Volgograd switches to Moscow time on 2020-12-27 at 02:00.
24 Changes to future timestamps
26 Volgograd changes time zone from +04 to +03 on 2020-12-27 at 02:00.
27 (Thanks to Alexander Krivenyshev and Stepan Golosunov.)
29 Changes to past timestamps
31 Correct many pre-1986 transitions, fixing entries originally
32 derived from Shanks. The fixes include:
33 - Australia: several 1917 through 1971 transitions
34 - Bahamas: several 1941 through 1945 transitions
35 - Bermuda: several 1917 through 1956 transitions
36 - Belize: several 1942 through 1968 transitions
37 - Ghana: several 1915 through 1956 transitions
38 - Israel and Palestine: several 1940 through 1985 transitions
39 - Kenya and adjacent: several 1908 through 1960 transitions
40 - Nigeria and adjacent: correcting LMT in Lagos, and several 1905
41 through 1919 transitions
42 - Seychelles: the introduction of standard time in 1907, not 1906
43 - Vanuatu: DST in 1973-1974, and a corrected 1984 transition
46 Because of the Australia change, Australia/Currie (King Island) is
47 no longer needed, as it is identical to Australia/Hobart for all
48 timestamps since 1970 and was therefore created by mistake.
49 Australia/Currie has been moved to the 'backward' file and its
50 corrected data moved to the 'backzone' file.
52 Changes to past time zone abbreviations and DST flags
54 To better match legislation in Turks and Caicos, the 2015 shift to
55 year-round observance of -04 is now modeled as AST throughout before
56 returning to Eastern Time with US DST in 2018, rather than as
57 maintaining EDT until 2015-11-01. (Thanks to P Chan.)
59 Changes to documentation
61 The zic man page now documents zic's coalescing of transitions
62 when a zone falls back just before DST springs forward.
65 Release 2020d - 2020-10-21 11:24:13 -0700
68 Palestine ends DST earlier than predicted, on 2020-10-24.
70 Changes to past and future timestamps
72 Palestine ends DST on 2020-10-24 at 01:00, instead of 2020-10-31
73 as previously predicted (thanks to Sharef Mustafa.) Its
74 2019-10-26 fall-back was at 00:00, not 01:00 (thanks to Steffen
75 Thorsen.) Its 2015-10-23 transition was at 01:00 not 00:00, and
76 its spring 2020 transition was on March 28 at 00:00, not March 27
77 (thanks to Pierre Cashon.) This affects Asia/Gaza and
78 Asia/Hebron. Assume future spring and fall transitions will be on
79 the Saturday preceding the last Sunday of March and October,
83 Release 2020c - 2020-10-16 11:15:53 -0700
86 Fiji starts DST later than usual, on 2020-12-20.
88 Changes to future timestamps
90 Fiji will start DST on 2020-12-20, instead of 2020-11-08 as
91 previously predicted. DST will still end on 2021-01-17.
92 (Thanks to Raymond Kumar and Alan Mintz.) Assume for now that
93 the later-than-usual start date is a one-time departure from the
96 Changes to build procedure
98 Rearguard tarballs now contain an empty file pacificnew.
99 Some older downstream software expects this file to exist.
100 (Problem reported by Mike Cullinan.)
103 Release 2020b - 2020-10-06 18:35:04 -0700
106 Revised predictions for Morocco's changes starting in 2023.
107 Canada's Yukon changes to -07 on 2020-11-01, not 2020-03-08.
108 Macquarie Island has stayed in sync with Tasmania since 2011.
109 Casey, Antarctica is at +08 in winter and +11 in summer.
110 zic no longer supports -y, nor the TYPE field of Rules.
112 Changes to future timestamps
114 Morocco's spring-forward after Ramadan is now predicted to occur
115 no sooner than two days after Ramadan, instead of one day.
116 (Thanks to Milamber.) The first altered prediction is for 2023,
117 now predicted to spring-forward on April 30 instead of April 23.
119 Changes to past and future timestamps
121 Casey Station, Antarctica has been using +08 in winter and +11 in
122 summer since 2018. The most recent transition from +08 to +11 was
123 2020-10-04 00:01. Also, Macquarie Island has been staying in
124 sync with Tasmania since 2011. (Thanks to Steffen Thorsen.)
126 Changes to past and future time zone abbreviations and DST flags
128 Canada's Yukon, represented by America/Whitehorse and
129 America/Dawson, changes its time zone rules from -08/-07 to
130 permanent -07 on 2020-11-01, not on 2020-03-08 as 2020a had it.
131 This change affects only the time zone abbreviation (MST vs PDT)
132 and daylight saving flag for the period between the two dates.
133 (Thanks to Andrew G. Smith.)
135 Changes to past timestamps
137 Correct several transitions for Hungary for 1918/1983.
138 For example, the 1983-09-25 fall-back was at 01:00, not 03:00.
139 (Thanks to Géza Nyáry.) Also, the 1890 transition to standard
140 time was on 11-01, not 10-01 (thanks to Michael Deckers).
142 The 1891 French transition was on March 16, not March 15. The
143 1911-03-11 French transition was at midnight, not a minute later.
144 Monaco's transitions were on 1892-06-01 and 1911-03-29, not
145 1891-03-15 and 1911-03-11. (Thanks to Michael Deckers.)
149 Support for zic's long-obsolete '-y YEARISTYPE' option has been
150 removed and, with it, so has support for the TYPE field in Rule
151 lines, which is now reserved for compatibility with earlier zic.
152 These features were previously deprecated in release 2015f.
153 (Thanks to Tim Parenti.)
155 zic now defaults to '-b slim' instead of to '-b fat'.
157 zic's new '-l -' and '-p -' options uninstall any existing
158 localtime and posixrules files, respectively.
160 The undocumented and ineffective tzsetwall function has been
163 Changes to build procedure
165 The Makefile now defaults POSIXRULES to '-', so the posixrules
166 feature (obsolete as of 2019b) is no longer installed by default.
168 Changes to documentation and commentary
170 The long-obsolete files pacificnew, systemv, and yearistype.sh have
171 been removed from the distribution. (Thanks to Tim Parenti.)
174 Release 2020a - 2020-04-23 16:03:47 -0700
177 Morocco springs forward on 2020-05-31, not 2020-05-24.
178 Canada's Yukon advanced to -07 year-round on 2020-03-08.
179 America/Nuuk renamed from America/Godthab.
180 zic now supports expiration dates for leap second lists.
182 Changes to future timestamps
184 Morocco's second spring-forward transition in 2020 will be May 31,
185 not May 24 as predicted earlier. (Thanks to Semlali Naoufal.)
186 Adjust future-year predictions to use the first Sunday after the
187 day after Ramadan, not the first Sunday after Ramadan.
189 Canada's Yukon, represented by America/Whitehorse and
190 America/Dawson, advanced to -07 year-round, beginning with its
191 spring-forward transition on 2020-03-08, and will not fall back on
192 2020-11-01. Although a government press release calls this
193 "permanent Pacific Daylight Saving Time", we prefer MST for
194 consistency with nearby Dawson Creek, Creston, and Fort Nelson.
195 (Thanks to Tim Parenti.)
197 Changes to past timestamps
199 Shanghai observed DST in 1919. (Thanks to Phake Nick.)
201 Changes to timezone identifiers
203 To reflect current usage in English better, America/Godthab has
204 been renamed to America/Nuuk. A backwards-compatibility link
205 remains for the old name.
209 localtime.c no longer mishandles timestamps after the last
210 transition in a TZif file with leap seconds and with daylight
211 saving time transitions projected into the indefinite future.
212 For example, with TZ='America/Los_Angeles' with leap seconds,
213 zdump formerly reported a DST transition on 2038-03-14
214 from 01:59:32.999... to 02:59:33 instead of the correct transition
215 from 01:59:59.999... to 03:00:00.
217 zic -L now supports an Expires line in the leapseconds file, and
218 truncates the TZif output accordingly. This propagates leap
219 second expiration information into the TZif file, and avoids the
220 abovementioned localtime.c bug as well as similar bugs present in
221 many client implementations. If no Expires line is present, zic
222 -L instead truncates the TZif output based on the #expires comment
223 present in leapseconds files distributed by tzdb 2018f and later;
224 however, this usage is obsolescent. For now, the distributed
225 leapseconds file has an Expires line that is commented out, so
226 that the file can be fed to older versions of zic which ignore the
227 commented-out line. Future tzdb distributions are planned to
228 contain a leapseconds file with an Expires line.
230 The configuration macros HAVE_TZNAME and USG_COMPAT should now be
231 set to 1 if the system library supports the feature, and 2 if not.
232 As before, these macros are nonzero if tzcode should support the
233 feature, zero otherwise.
235 The configuration macro ALTZONE now has the same values with the
236 same meaning as HAVE_TZNAME and USG_COMPAT.
238 The code's defense against CRLF in leap-seconds.list is now
239 portable to POSIX awk. (Problem reported by Deborah Goldsmith.)
241 Although the undocumented tzsetwall function is not changed in
242 this release, it is now deprecated in preparation for removal in
243 future releases. Due to POSIX requirements, tzsetwall has not
244 worked for some time. Any code that uses it should instead use
245 tzalloc(NULL) or, if portability trumps thread-safety, should
246 unset the TZ environment variable.
248 Changes to commentary
250 The Îles-de-la-Madeleine and the Listuguj reserve are noted as
251 following America/Halifax, and comments about Yukon's "south" and
252 "north" have been corrected to say "east" and "west". (Thanks to
256 Release 2019c - 2019-09-11 08:59:48 -0700
259 Fiji observes DST from 2019-11-10 to 2020-01-12.
260 Norfolk Island starts observing Australian-style DST.
262 Changes to future timestamps
264 Fiji's next DST transitions will be 2019-11-10 and 2020-01-12
265 instead of 2019-11-03 and 2020-01-19. (Thanks to Raymond Kumar.)
266 Adjust future guesses accordingly.
268 Norfolk Island will observe Australian-style DST starting in
269 spring 2019. The first transition is on 2019-10-06. (Thanks to
270 Kyle Czech and Michael Deckers.)
272 Changes to past timestamps
274 Many corrections to time in Turkey from 1940 through 1985.
275 (Thanks to Oya Vulaş via Alois Treindl, and to Kıvanç Yazan.)
277 The Norfolk Island 1975-03-02 transition was at 02:00 standard
278 time, not 02:00 DST. (Thanks to Michael Deckers.)
280 South Korea observed DST from 1948 through 1951. Although this
281 info was supposed to appear in release 2014j, a typo inadvertently
282 suppressed the change. (Thanks to Alois Treindl.)
284 Detroit observed DST in 1967 and 1968 following the US DST rules,
285 except that its 1967 DST began on June 14 at 00:01. (Thanks to
286 Alois Treindl for pointing out that the old data entries were
289 Fix several errors in pre-1970 transitions in Perry County, IN.
290 (Thanks to Alois Triendl for pointing out the 1967/9 errors.)
292 Edmonton did not observe DST in 1967 or 1969. In 1946 Vancouver
293 ended DST on 09-29 not 10-13, and Vienna ended DST on 10-07 not
294 10-06. In 1945 Königsberg (now Kaliningrad) switched from +01/+02
295 to +02/+03 on 04-10 not 01-01, and its +02/+03 is abbreviated
296 EET/EEST, not CET/CEST. (Thanks to Alois Triendl.) In 1946
297 Königsberg switched to +03 on 04-07 not 01-01.
299 In 1946 Louisville switched from CST to CDT on 04-28 at 00:01, not
300 01-01 at 00:00. (Thanks to Alois Treindl and Michael Deckers.)
301 Also, it switched from CST to CDT on 1950-04-30, not 1947-04-27.
303 The 1892-05-01 transition in Brussels was at 00:17:30, not at noon.
304 (Thanks to Michael Deckers.)
306 Changes to past time zone abbreviations and DST flags
308 Hong Kong Winter Time, observed from 1941-10-01 to 1941-12-25,
309 is now flagged as DST and is abbreviated HKWT not HKT.
313 leapseconds.awk now relies only on its input data, rather than
314 also relying on its comments. (Inspired by code from Dennis
315 Ferguson and Chris Woodbury.)
317 The code now defends against CRLFs in leap-seconds.list.
318 (Thanks to Brian Inglis and Chris Woodbury.)
320 Changes to documentation and commentary
322 theory.html discusses leap seconds. (Thanks to Steve Summit.)
324 Nashville's newspapers dueled about the time of day in the 1950s.
325 (Thanks to John Seigenthaler.)
327 Liechtenstein observed Swiss DST in 1941/2.
328 (Thanks to Alois Treindl.)
331 Release 2019b - 2019-07-01 00:09:53 -0700
334 Brazil no longer observes DST.
335 'zic -b slim' outputs smaller TZif files; please try it out.
336 Palestine's 2019 spring-forward transition was on 03-29, not 03-30.
338 Changes to future timestamps
340 Brazil has canceled DST and will stay on standard time indefinitely.
341 (Thanks to Steffen Thorsen, Marcus Diniz, and Daniel Soares de
344 Predictions for Morocco now go through 2087 instead of 2037, to
345 work around a problem on newlib when using TZif files output by
346 zic 2019a or earlier. (Problem reported by David Gauchard.)
348 Changes to past and future timestamps
350 Palestine's 2019 spring transition was 03-29 at 00:00, not 03-30
351 at 01:00. (Thanks to Sharef Mustafa and Even Scharning.) Guess
352 future transitions to be March's last Friday at 00:00.
354 Changes to past timestamps
356 Hong Kong's 1941-06-15 spring-forward transition was at 03:00, not
357 03:30. Its 1945 transition from JST to HKT was on 11-18 at 02:00,
358 not 09-15 at 00:00. In 1946 its spring-forward transition was on
359 04-21 at 00:00, not the previous day at 03:30. From 1946 through
360 1952 its fall-back transitions occurred at 04:30, not at 03:30.
361 In 1947 its fall-back transition was on 11-30, not 12-30.
364 Changes to past time zone abbreviations
366 Italy's 1866 transition to Rome Mean Time was on December 12, not
367 September 22. This affects only the time zone abbreviation for
368 Europe/Rome between those dates. (Thanks to Stephen Trainor and
371 Changes affecting metadata only
373 Add info about the Crimea situation in zone1970.tab and zone.tab.
374 (Problem reported by Serhii Demediuk.)
378 zic's new -b option supports a way to control data bloat and to
379 test for year-2038 bugs in software that reads TZif files.
380 'zic -b fat' and 'zic -b slim' generate larger and smaller output;
381 for example, changing from fat to slim shrinks the Europe/London
382 file from 3648 to 1599 bytes, saving about 56%. Fat and slim
383 files represent the same set of timestamps and use the same TZif
384 format as documented in tzfile(5) and in Internet RFC 8536.
385 Fat format attempts to work around bugs or incompatibilities in
386 older software, notably software that mishandles 64-bit TZif data
387 or uses obsolete TZ strings like "EET-2EEST" that lack DST rules.
388 Slim format is more efficient and does not work around 64-bit bugs
389 or obsolete TZ strings. Currently zic defaults to fat format
390 unless you compile with -DZIC_BLOAT_DEFAULT=\"slim\"; this
391 out-of-the-box default is intended to change in future releases
392 as the buggy software often mishandles timestamps anyway.
394 zic no longer treats a set of rules ending in 2037 specially.
395 Previously, zic assumed that such a ruleset meant that future
396 timestamps could not be predicted, and therefore omitted a
397 POSIX-like TZ string in the TZif output. The old behavior is no
398 longer needed for current tzdata, and caused problems with newlib
399 when used with older tzdata (reported by David Gauchard).
401 zic no longer generates some artifact transitions. For example,
402 Europe/London no longer has a no-op transition in January 1996.
404 Changes to build procedure
406 tzdata.zi now assumes zic 2017c or later. This shrinks tzdata.zi
409 Changes to documentation and commentary
411 The Makefile now documents the POSIXRULES macro as being obsolete,
412 and similarly, zic's -p POSIXRULES option is now documented as
413 being obsolete. Although the POSIXRULES feature still exists and
414 works as before, in practice it is rarely used for its intended
415 purpose, and it does not work either in the default reference
416 implementation (for timestamps after 2037) or in common
417 implementations such as GNU/Linux (for contemporary timestamps).
418 Since POSIXRULES was designed primarily as a temporary transition
419 facility for System V platforms that died off decades ago, it is
420 being decommissioned rather than institutionalized.
422 New info on Bonin Islands and Marcus (thanks to Wakaba and Phake Nick).
425 Release 2019a - 2019-03-25 22:01:33 -0700
428 Palestine "springs forward" on 2019-03-30 instead of 2019-03-23.
429 Metlakatla "fell back" to rejoin Alaska Time on 2019-01-20 at 02:00.
431 Changes to past and future timestamps
433 Palestine will not start DST until 2019-03-30, instead of 2019-03-23 as
434 previously predicted. Adjust our prediction by guessing that spring
435 transitions will be between 24 and 30 March, which matches recent practice
436 since 2016. (Thanks to Even Scharning and Tim Parenti.)
438 Metlakatla ended its observance of Pacific standard time,
439 rejoining Alaska Time, on 2019-01-20 at 02:00. (Thanks to Ryan
440 Stanley and Tim Parenti.)
442 Changes to past timestamps
444 Israel observed DST in 1980 (08-02/09-13) and 1984 (05-05/08-25).
445 (Thanks to Alois Treindl and Isaac Starkman.)
447 Changes to time zone abbreviations
449 Etc/UCT is now a backward-compatibility link to Etc/UTC, instead
450 of being a separate zone that generates the abbreviation "UCT",
451 which nowadays is typically a typo. (Problem reported by Isiah
456 zic now has an -r option to limit the time range of output data.
457 For example, 'zic -r @1000000000' limits the output data to
458 timestamps starting 1000000000 seconds after the Epoch.
459 This helps shrink output size and can be useful for applications
460 not needing the full timestamp history, such as TZDIST truncation;
461 see Internet RFC 8536 section 5.1. (Inspired by a feature request
462 from Christopher Wong, helped along by bug reports from Wong and
465 Changes to documentation
467 Mention Internet RFC 8536 (February 2019), which documents TZif.
469 tz-link.html now cites tzdata-meta
470 <https://tzdata-meta.timtimeonline.com/>.
473 Release 2018i - 2018-12-30 11:05:43 -0800
476 São Tomé and Príncipe switches from +01 to +00 on 2019-01-01.
478 Changes to future timestamps
480 Due to a change in government, São Tomé and Príncipe switches back
481 from +01 to +00 on 2019-01-01 at 02:00. (Thanks to Vadim
482 Nasardinov and Michael Deckers.)
485 Release 2018h - 2018-12-23 17:59:32 -0800
488 Qyzylorda, Kazakhstan moved from +06 to +05 on 2018-12-21.
489 New zone Asia/Qostanay because Qostanay, Kazakhstan didn't move.
490 Metlakatla, Alaska observes PST this winter only.
491 Guess Morocco will continue to adjust clocks around Ramadan.
492 Add predictions for Iran from 2038 through 2090.
494 Changes to future timestamps
496 Guess that Morocco will continue to fall back just before and
497 spring forward just after Ramadan, the practice since 2012.
498 (Thanks to Maamar Abdelkader.) This means Morocco will observe
499 negative DST during Ramadan in main and vanguard formats, and in
500 rearguard format it stays in the +00 timezone and observes
501 ordinary DST in all months other than Ramadan. As before, extend
502 this guesswork to the year 2037. As a consequence, Morocco is
503 scheduled to observe three DST transitions in some Gregorian years
504 (e.g., 2033) due to the mismatch between the Gregorian and Islamic
507 The table of exact transitions for Iranian DST has been extended.
508 It formerly cut off before the year 2038 in a nod to 32-bit time_t.
509 It now cuts off before 2091 as there is doubt about how the Persian
510 calendar will treat 2091. This change predicts DST transitions in
511 2038-9, 2042-3, and 2046-7 to occur one day later than previously
512 predicted. As before, post-cutoff transitions are approximated.
514 Changes to past and future timestamps
516 Qyzylorda (aka Kyzylorda) oblast in Kazakhstan moved from +06 to
517 +05 on 2018-12-21. This is a zone split as Qostanay (aka
518 Kostanay) did not switch, so create a zone Asia/Qostanay.
520 Metlakatla moved from Alaska to Pacific standard time on 2018-11-04.
521 It did not change clocks that day and remains on -08 this winter.
522 (Thanks to Ryan Stanley.) It will revert to the usual Alaska
523 rules next spring, so this change affects only timestamps
524 from 2018-11-04 through 2019-03-10.
526 Change to past timestamps
528 Kwajalein's 1993-08-20 transition from -12 to +12 was at 24:00,
529 not 00:00. I transcribed the time incorrectly from Shanks.
530 (Thanks to Phake Nick.)
532 Nauru's 1979 transition was on 02-10 at 02:00, not 05-01 at 00:00.
533 (Thanks to Phake Nick.)
535 Guam observed DST irregularly from 1959 through 1977.
536 (Thanks to Phake Nick.)
538 Hong Kong observed DST in 1941 starting 06-15 (not 04-01), then on
539 10-01 changed standard time to +08:30 (not +08). Its transition
540 back to +08 after WWII was on 1945-09-15, not the previous day.
541 Its 1904-10-30 change took effect at 01:00 +08 (not 00:00 LMT).
542 (Thanks to Phake Nick, Steve Allen, and Joseph Myers.) Also,
543 its 1952 fallback was on 11-02 (not 10-25).
545 This release contains many changes to timestamps before 1946 due
546 to Japanese possession or occupation of Pacific/Chuuk,
547 Pacific/Guam, Pacific/Kosrae, Pacific/Kwajalein, Pacific/Majuro,
548 Pacific/Nauru, Pacific/Palau, and Pacific/Pohnpei.
549 (Thanks to Phake Nick.)
551 Assume that the Spanish East Indies was like the Philippines and
552 observed American time until the end of 1844. This affects
553 Pacific/Chuuk, Pacific/Kosrae, Pacific/Palau, and Pacific/Pohnpei.
555 Changes to past tm_isdst flags
557 For the recent Morocco change, the tm_isdst flag should be 1 from
558 2018-10-27 00:00 to 2018-10-28 03:00. (Thanks to Michael Deckers.)
559 Give a URL to the official decree. (Thanks to Matt Johnson.)
562 Release 2018g - 2018-10-26 22:22:45 -0700
565 Morocco switches to permanent +01 on 2018-10-28.
567 Changes to future timestamps
569 Morocco switches from +00/+01 to permanent +01 effective 2018-10-28,
570 so its clocks will not fall back as previously scheduled.
571 (Thanks to Mohamed Essedik Najd and Brian Inglis.)
575 When generating TZif files with leap seconds, zic no longer uses a
576 format that trips up older 32-bit clients, fixing a bug introduced
577 in 2018f. (Reported by Daniel Fischer.) Also, the zic workaround
578 for QTBUG-53071 now also works for TZif files with leap seconds.
580 The translator to rearguard format now rewrites the line
581 "Rule Japan 1948 1951 - Sep Sat>=8 25:00 0 S" to
582 "Rule Japan 1948 1951 - Sep Sun>=9 1:00 0 S".
583 This caters to zic before 2007 and to Oracle TZUpdater 2.2.0
584 and earlier. (Reported by Christos Zoulas.)
586 Changes to past time zone abbreviations
588 Change HDT to HWT/HPT for WWII-era abbreviations in Hawaii.
589 This reverts to 2011h, as the abbreviation change in 2011i was
592 Changes to documentation
594 tzfile.5 has new sections on interoperability issues.
597 Release 2018f - 2018-10-18 00:14:18 -0700
600 Volgograd moves from +03 to +04 on 2018-10-28.
601 Fiji ends DST 2019-01-13, not 2019-01-20.
602 Most of Chile changes DST dates, effective 2019-04-06.
604 Changes to future timestamps
606 Volgograd moves from +03 to +04 on 2018-10-28 at 02:00.
607 (Thanks to Alexander Fetisov and Stepan Golosunov.)
609 Fiji ends DST 2019-01-13 instead of the 2019-01-20 previously
610 predicted. (Thanks to Raymond Kumar.) Adjust future predictions
613 Most of Chile will end DST on the first Saturday in April at 24:00 mainland
614 time, and resume DST on the first Saturday in September at 24:00 mainland
615 time. The changes are effective from 2019-04-06, and do not affect the
616 Magallanes region modeled by America/Punta_Arenas. (Thanks to Juan Correa
617 and Tim Parenti.) Adjust future predictions accordingly.
619 Changes to past timestamps
621 The 2018-05-05 North Korea 30-minute time zone change took place
622 at 23:30 the previous day, not at 00:00 that day.
624 China's 1988 spring-forward transition was on April 17, not
625 April 10. Its DST transitions in 1986/91 were at 02:00, not 00:00.
628 Fix several issues for Macau before 1992. Macau's pre-1904 LMT
629 was off by 10 s. Macau switched to +08 in 1904 not 1912, and
630 temporarily switched to +09/+10 during World War II. Macau
631 observed DST in 1942/79, not 1961/80, and there were several
632 errors for transition times and dates. (Thanks to P Chan.)
634 The 1948-1951 fallback transitions in Japan were at 25:00 on
635 September's second Saturday, not at 24:00. (Thanks to Phake Nick.)
636 zic turns this into 01:00 on the day after September's second
637 Saturday, which is the best that POSIX or C platforms can do.
639 Incorporate 1940-1949 Asia/Shanghai DST transitions from a 2014
640 paper by Li Yu, replacing more-questionable data from Shanks.
642 Changes to time zone abbreviations
644 Use "PST" and "PDT" for Philippine time. (Thanks to Paul Goyette.)
648 zic now always generates TZif files where time type 0 is used for
649 timestamps before the first transition. This simplifies the
650 reading of TZif files and should not affect behavior of existing
651 TZif readers because the same set of time types is used; only
652 their internal indexes may have changed. This affects only the
653 legacy zones EST5EDT, CST6CDT, MST7MDT, PST8PDT, CET, MET, and
654 EET, which previously used nonzero types for these timestamps.
656 Because of the type 0 change, zic no longer outputs a dummy
657 transition at time -2**59 (before the Big Bang), as clients should
658 no longer need this to handle historical timestamps correctly.
659 This reverts a change introduced in 2013d and shrinks most TZif
660 files by a few bytes.
662 zic now supports negative time-of-day in Rule and Leap lines, e.g.,
663 "Rule X min max - Apr lastSun -6:00 1:00 -" means the transition
664 occurs at 18:00 on the Saturday before the last Sunday in April.
665 This behavior was documented in 2018a but the code did not
666 entirely match the documentation.
668 localtime.c no longer requires at least one time type in TZif
669 files that lack transitions or have a POSIX-style TZ string. This
670 future-proofs the code against possible future extensions to the
671 format that would allow TZif files with POSIX-style TZ strings and
672 without transitions or time types.
674 A read-access subscript error in localtime.c has been fixed.
675 It could occur only in TZif files with timecnt == 0, something that
676 does not happen in practice now but could happen in future versions.
678 localtime.c no longer ignores TZif POSIX-style TZ strings that
679 specify only standard time. Instead, these TZ strings now
680 override the default time type for timestamps after the last
681 transition (or for all timestamps if there are no transitions),
682 just as DST strings specifying DST have always done.
684 leapseconds.awk now outputs "#updated" and "#expires" comments,
685 and supports leap seconds at the ends of months other than June
686 and December. (Inspired by suggestions from Chris Woodbury.)
688 Changes to documentation
690 New restrictions: A Rule name must start with a character that
691 is neither an ASCII digit nor "-" nor "+", and an unquoted name
692 should not use characters in the set "!$%&'()*,/:;<=>?@[\]^`{|}~".
693 The latter restriction makes room for future extensions (a
694 possibility noted by Tom Lane).
696 tzfile.5 now documents what time types apply before the first and
697 after the last transition, if any.
699 Documentation now uses the spelling "timezone" for a TZ setting
700 that determines timestamp history, and "time zone" for a
701 geographic region currently sharing the same standard time.
703 The name "TZif" is now used for the tz binary data format.
705 tz-link.htm now mentions the A0 TimeZone Migration utilities.
706 (Thanks to Aldrin Martoq for the link.)
708 Changes to build procedure
710 New 'make' target 'rearguard_tarballs' to build the rearguard
711 tarball only. This is a convenience on platforms that lack lzip
712 if you want to build the rearguard tarball. (Problem reported by
715 tzdata.zi is now more stable from release to release. (Problem
716 noted by Tom Lane.) It is also a bit shorter.
718 tzdata.zi now can contain comment lines documenting configuration
719 information, such as which data format was selected, which input
720 files were used, and how leap seconds are treated. (Problems
721 noted by Lester Caine and Brian Inglis.) If the Makefile defaults
722 are used these comment lines are absent, for backward
723 compatibility. A redistributor intending to alter its copy of the
724 files should also append "-LABEL" to the 'version' file's first
725 line, where "LABEL" identifies the redistributor's change.
728 Release 2018e - 2018-05-01 23:42:51 -0700
732 North Korea switches back to +09 on 2018-05-05.
733 The main format uses negative DST again, for Ireland etc.
734 'make tarballs' now also builds a rearguard tarball.
735 New 's' and 'd' suffixes in SAVE columns of Rule and Zone lines.
737 Changes to past and future timestamps
739 North Korea switches back from +0830 to +09 on 2018-05-05.
740 (Thanks to Kang Seonghoon, Arthur David Olson, Seo Sanghyeon,
743 Bring back the negative-DST changes of 2018a, except be more
744 compatible with data parsers that do not support negative DST.
745 Also, this now affects historical timestamps in Namibia and the
746 former Czechoslovakia, not just Ireland. The main format now uses
747 negative DST to model timestamps in Europe/Dublin (from 1971 on),
748 Europe/Prague (1946/7), and Africa/Windhoek (1994/2017). This
749 does not affect UT offsets, only time zone abbreviations and the
750 tm_isdst flag. Also, this does not affect rearguard or vanguard
751 formats; effectively the main format now uses vanguard instead of
752 rearguard format. Data parsers that do not support negative DST
753 can still use data from the rearguard tarball described below.
755 Changes to build procedure
757 The command 'make tarballs' now also builds the tarball
758 tzdataVERSION-rearguard.tar.gz, which is like tzdataVERSION.tar.gz
759 except that it uses rearguard format intended for trailing-edge
762 Changes to data format and to code
764 The SAVE column of Rule and Zone lines can now have an 's' or 'd'
765 suffix, which specifies whether the adjusted time is standard time
766 or daylight saving time. If no suffix is given, daylight saving
767 time is used if and only if the SAVE column is nonzero; this is
768 the longstanding behavior. Although this new feature is not used
769 in tzdata, it could be used to specify the legal time in Namibia
770 1994-2017, as opposed to the popular time (see below).
772 Changes to past timestamps
774 From 1994 through 2017 Namibia observed DST in winter, not summer.
775 That is, it used negative DST, as Ireland still does. This change
776 does not affect UTC offsets; it affects only the tm_isdst flag and
777 the abbreviation used during summer, which is now CAT, not WAST.
778 Although (as noted by Michael Deckers) summer and winter time were
779 both simply called "standard time" in Namibian law, in common
780 practice winter time was considered to be DST (as noted by Stephen
781 Colebourne). The full effect of this change is only in vanguard
782 and main format; in rearguard format, the tm_isdst flag is still
783 zero in winter and nonzero in summer.
785 In 1946/7 Czechoslovakia also observed negative DST in winter.
786 The full effect of this change is only in vanguard and main
787 formats; in rearguard format, it is modeled as plain GMT without
788 daylight saving. Also, the dates of some 1944/5 DST transitions
789 in Czechoslovakia have been changed.
792 Release 2018d - 2018-03-22 07:05:46 -0700
796 Palestine starts DST a week earlier in 2018.
797 Add support for vanguard and rearguard data consumers.
798 Add subsecond precision to source data format, though not to data.
800 Changes to future timestamps
802 In 2018, Palestine starts DST on March 24, not March 31.
803 Adjust future predictions accordingly. (Thanks to Sharef Mustafa.)
805 Changes to past and future timestamps
807 Casey Station in Antarctica changed from +11 to +08 on 2018-03-11
808 at 04:00. (Thanks to Steffen Thorsen.)
810 Changes to past timestamps
812 Historical transitions for Uruguay, represented by
813 America/Montevideo, have been updated per official legal documents,
814 replacing previous data mainly originating from the inventions of
815 Shanks & Pottenger. This has resulted in adjustments ranging from
816 30 to 90 minutes in either direction over at least two dozen
817 distinct periods ranging from one day to several years in length.
818 A mere handful of pre-1991 transitions are unaffected; data since
819 then has come from more reliable contemporaneous reporting. These
820 changes affect various timestamps in 1920-1923, 1936, 1939,
821 1942-1943, 1959, 1966-1970, 1972, 1974-1980, and 1988-1990.
822 Additionally, Uruguay's pre-standard-time UT offset has been
823 adjusted westward by 7 seconds, from UT-03:44:44 to UT-03:44:51, to
824 match the location of the Observatory of the National Meteorological
825 Institute in Montevideo.
826 (Thanks to Jeremie Bonjour, Tim Parenti, and Michael Deckers.)
828 Enderbury and Kiritimati skipped New Year's Eve 1994, not
829 New Year's Day 1995. (Thanks to Kerry Shetline.)
831 Fix the 1912-01-01 transition for Portugal and its colonies.
832 This transition was at 00:00 according to the new UT offset, not
833 according to the old one. Also assume that Cape Verde switched on
834 the same date as the rest, not in 1907. This affects
835 Africa/Bissau, Africa/Sao_Tome, Asia/Macau, Atlantic/Azores,
836 Atlantic/Cape_Verde, Atlantic/Madeira, and Europe/Lisbon.
837 (Thanks to Michael Deckers.)
839 Fix an off-by-1 error for pre-1913 timestamps in Jamaica and in
842 Changes to past time zone abbreviations
844 MMT took effect in Uruguay from 1908-06-10, not 1898-06-28. There
845 is no clock change associated with the transition.
847 Changes to build procedure
849 The new DATAFORM macro in the Makefile lets the installer choose
850 among three source data formats. The idea is to lessen downstream
851 disruption when data formats are improved.
853 * DATAFORM=vanguard installs from the latest, bleeding-edge
854 format. DATAFORM=main (the default) installs from the format
855 used in the 'africa' etc. files. DATAFORM=rearguard installs
856 from a trailing-edge format. Eventually, elements of today's
857 vanguard format should move to the main format, and similarly
858 the main format's features should eventually move to the
861 * In the current version, the main and rearguard formats are
862 identical and match that of 2018c, so this change does not
863 affect default behavior. The vanguard format currently contains
864 one feature not in the main format: negative SAVE values. This
865 improves support for Ireland, which uses Irish Standard Time
866 (IST, UTC+01) in summer and GMT (UTC) in winter. tzcode has
867 supported negative SAVE values for decades, and this feature
868 should move to the main format soon. However, it will not move
869 to the rearguard format for quite some time because some
870 downstream parsers do not support it.
872 * The build procedure constructs three files vanguard.zi, main.zi,
873 and rearguard.zi, one for each format. Although the files
874 represent essentially the same data, they may have minor
875 discrepancies that users are not likely to notice. The files
876 are intended for downstream data consumers and are not
877 installed. Zoneinfo parsers that do not support negative SAVE values
878 should start using rearguard.zi, so that they will be unaffected
879 when the negative-DST feature moves from vanguard to main.
880 Bleeding-edge Zoneinfo parsers that support the new features
881 already can use vanguard.zi; in this respect, current tzcode is
884 The Makefile should now be safe for parallelized builds, and 'make
885 -j to2050new.tzs' is now much faster on a multiprocessor host
888 When built with -DSUPPRESS_TZDIR, the tzcode library no longer
889 prepends TZDIR/ to file names that do not begin with '/'. This is
890 not recommended for general use, due to its security implications.
891 (From a suggestion by Manuela Friedrich.)
895 zic now accepts subsecond precision in expressions like
896 00:19:32.13, which is approximately the legal time of the
897 Netherlands from 1835 to 1937. However, because it is
898 questionable whether the few recorded uses of non-integer offsets
899 had subsecond precision in practice, there are no plans for tzdata
900 to use this feature. (Thanks to Steve Allen for pointing out
901 the limitations of historical data in this area.)
903 The code is a bit more portable to MS-Windows. Installers can
904 compile with -DRESERVE_STD_EXT_IDS on MS-Windows platforms that
905 reserve identifiers like 'localtime'. (Thanks to Manuela
908 Changes to documentation and commentary
910 theory.html now outlines tzdb's extensions to POSIX's model for
911 civil time, and has a section "POSIX features no longer needed"
912 that lists POSIX API components that are now vestigial.
913 (From suggestions by Steve Summit.) It also better distinguishes
914 time zones from tz regions. (From a suggestion by Guy Harris.)
916 Commentary is now more consistent about using the phrase "daylight
917 saving time", to match the C name tm_isdst. Daylight saving time
918 need not occur in summer, and need not have a positive offset from
921 Commentary about historical transitions in Uruguay has been expanded
922 with links to many relevant legal documents.
923 (Thanks to Tim Parenti.)
925 Commentary now uses some non-ASCII characters with Unicode value
926 less than U+0100, as they can be useful and should work even with
927 older editors such as XEmacs.
930 Release 2018c - 2018-01-22 23:00:44 -0800
933 Revert Irish changes that relied on negative SAVE values.
937 Revert the 2018a change to Europe/Dublin. As before, this change
938 does not affect UT offsets or abbreviations; it affects only
939 whether timestamps are considered to be standard time or
940 daylight-saving time, as expressed in the tm_isdst flag of C's
941 struct tm type. This reversion is intended to be a temporary
942 workaround for problems discovered with downstream uses of
943 releases 2018a and 2018b, which implemented Irish time by using
944 negative SAVE values in the Eire rules of the 'europe' file.
945 Although negative SAVE values have been part of tzcode for many
946 years and are supported by many platforms, they were not
947 documented before 2018a and ICU and OpenJDK do not currently
948 support them. A mechanism to export data to platforms lacking
949 support for negative DST is planned to be developed before the
950 change is reapplied. (Problems reported by Deborah Goldsmith and
953 Changes to past timestamps
955 Japanese DST transitions (1948-1951) were Sundays at 00:00, not
956 Saturdays or Sundays at 02:00. (Thanks to Takayuki Nikai.)
958 Changes to build procedure
960 The build procedure now works around mawk 1.3.3's lack of support
961 for character class expressions. (Problem reported by Ohyama.)
964 Release 2018b - 2018-01-17 23:24:48 -0800
967 Fix a packaging problem in tz2018a, which was missing 'pacificnew'.
969 Changes to build procedure
971 The distribution now contains the file 'pacificnew' again.
972 This file was inadvertantly omitted in the 2018a distribution.
973 (Problem reported by Matias Fonzo.)
976 Release 2018a - 2018-01-12 22:29:21 -0800
979 São Tomé and Príncipe switched from +00 to +01.
980 Brazil's DST will now start on November's first Sunday.
981 Ireland's standard time is now in the summer, not the winter.
982 Use Debian-style installation locations, instead of 4.3BSD-style.
985 Changes to past and future timestamps
987 São Tomé and Príncipe switched from +00 to +01 on 2018-01-01 at
988 01:00. (Thanks to Steffen Thorsen and Michael Deckers.)
990 Changes to future timestamps
992 Starting in 2018 southern Brazil will begin DST on November's
993 first Sunday instead of October's third Sunday. (Thanks to
996 Changes to past timestamps
998 A discrepancy of 4 s in timestamps before 1931 in South Sudan has
999 been corrected. The 'backzone' and 'zone.tab' files did not agree
1000 with the 'africa' and 'zone1970.tab' files. (Problem reported by
1003 The abbreviation invented for Bolivia Summer Time (1931-2) is now
1004 BST instead of BOST, to be more consistent with the convention
1005 used for Latvian Summer Time (1918-9) and for British Summer Time.
1009 Change Europe/Dublin so that it observes Irish Standard Time (UT
1010 +01) in summer and GMT (as negative daylight-saving) in winter,
1011 instead of observing standard time (GMT) in winter and Irish
1012 Summer Time (UT +01) in summer. This change does not affect UT
1013 offsets or abbreviations; it affects only whether timestamps are
1014 considered to be standard time or daylight-saving time, as
1015 expressed in the tm_isdst flag of C's struct tm type.
1016 (Discrepancy noted by Derick Rethans.)
1018 Changes to build procedure
1020 The default installation locations have been changed to mostly
1021 match Debian circa 2017, instead of being designed as an add-on to
1022 4.3BSD circa 1986. This affects the Makefile macros TOPDIR,
1023 TZDIR, MANDIR, and LIBDIR. New Makefile macros TZDEFAULT, USRDIR,
1024 USRSHAREDIR, BINDIR, ZDUMPDIR, and ZICDIR let installers tailor
1025 locations more precisely. (This responds to suggestions from
1026 Brian Inglis and from Steve Summit.)
1028 The default installation procedure no longer creates the
1029 backward-compatibility link US/Pacific-New, which causes
1030 confusion during user setup (e.g., see Debian bug 815200).
1031 Use 'make BACKWARD="backward pacificnew"' to create the link
1032 anyway, for now. Eventually we plan to remove the link entirely.
1034 tzdata.zi now contains a version-number comment.
1035 (Suggested by Tom Lane.)
1037 The Makefile now quotes values like BACKWARD more carefully when
1038 passing them to the shell. (Problem reported by Zefram.)
1040 Builders no longer need to specify -DHAVE_SNPRINTF on platforms
1041 that have snprintf and use pre-C99 compilers. (Problem reported
1046 zic has a new option -t FILE that specifies the location of the
1047 file that determines local time when TZ is unset. The default for
1048 this location can be configured via the new TZDEFAULT makefile
1049 macro, which defaults to /etc/localtime.
1051 Diagnostics and commentary now distinguish UT from UTC more
1052 carefully; see theory.html for more information about UT vs UTC.
1054 zic has been ported to GCC 8's -Wstringop-truncation option.
1055 (Problem reported by Martin Sebor.)
1057 Changes to documentation and commentary
1059 The zic man page now documents the longstanding behavior that
1060 times and years can be out of the usual range, with negative times
1061 counting backwards from midnight and with year 0 preceding year 1.
1062 (Problem reported by Michael Deckers.)
1064 The theory.html file now mentions the POSIX limit of six chars
1065 per abbreviation, and lists alphabetic abbreviations used.
1067 The files tz-art.htm and tz-link.htm have been renamed to
1068 tz-art.html and tz-link.html, respectively, for consistency with
1069 other file names and to simplify web server configuration.
1072 Release 2017c - 2017-10-20 14:49:34 -0700
1075 Northern Cyprus switches from +03 to +02/+03 on 2017-10-29.
1076 Fiji ends DST 2018-01-14, not 2018-01-21.
1077 Namibia switches from +01/+02 to +02 on 2018-04-01.
1078 Sudan switches from +03 to +02 on 2017-11-01.
1079 Tonga likely switches from +13/+14 to +13 on 2017-11-05.
1080 Turks & Caicos switches from -04 to -05/-04 on 2018-11-04.
1081 A new file tzdata.zi now holds a small text copy of all data.
1082 The zic input format has been regularized slightly.
1084 Changes to future timestamps
1086 Northern Cyprus has decided to resume EU rules starting
1087 2017-10-29, thus reinstituting winter time.
1089 Fiji ends DST 2018-01-14 instead of the 2018-01-21 previously
1090 predicted. (Thanks to Dominic Fok.) Adjust future predictions
1093 Namibia will switch from +01 with DST to +02 all year on
1094 2017-09-03 at 02:00. This affects UT offsets starting 2018-04-01
1095 at 02:00. (Thanks to Steffen Thorsen.)
1097 Sudan will switch from +03 to +02 on 2017-11-01. (Thanks to Ahmed
1098 Atyya and Yahia Abdalla.) South Sudan is not switching, so
1099 Africa/Juba is no longer a link to Africa/Khartoum.
1101 Tonga has likely ended its experiment with DST, and will not
1102 adjust its clocks on 2017-11-05. Although Tonga has not announced
1103 whether it will continue to observe DST, the IATA is assuming that
1104 it will not. (Thanks to David Wade.)
1106 Turks & Caicos will switch from -04 all year to -05 with US DST on
1107 2018-03-11 at 03:00. This affects UT offsets starting 2018-11-04
1108 at 02:00. (Thanks to Steffen Thorsen.)
1110 Changes to past timestamps
1112 Namibia switched from +02 to +01 on 1994-03-21, not 1994-04-03.
1113 (Thanks to Arthur David Olson.)
1115 Detroit did not observe DST in 1967.
1117 Use railway time for Asia/Kolkata before 1941, by switching to
1118 Madras local time (UT +052110) in 1870, then to IST (UT +0530) in
1119 1906. Also, treat 1941-2's +0630 as DST, like 1942-5.
1121 Europe/Dublin's 1946 and 1947 fallback transitions occurred at
1122 02:00 standard time, not 02:00 DST. (Thanks to Michael Deckers.)
1124 Pacific/Apia and Pacific/Pago_Pago switched from Antipodean to
1125 American time in 1892, not 1879. (Thanks to Michael Deckers.)
1127 Adjust the 1867 transition in Alaska to better reflect the
1128 historical record, by changing it to occur on 1867-10-18 at 15:30
1129 Sitka time rather than at the start of 1867-10-17 local time.
1130 Although strictly speaking this is accurate only for Sitka,
1131 the rest of Alaska's blanks need to be filled in somehow.
1133 Fix off-by-one errors in UT offsets for Adak and Nome before 1867.
1134 (Thanks to Michael Deckers.)
1136 Add 7 s to the UT offset in Asia/Yangon before 1920.
1138 Changes to zone names
1140 Remove Canada/East-Saskatchewan from the 'backward' file, as it
1141 exceeded the 14-character limit and was an unused misnomer anyway.
1143 Changes to build procedure
1145 To support applications that prefer to read time zone data in text
1146 form, two zic input files tzdata.zi and leapseconds are now
1147 installed by default. The commands 'zic tzdata.zi' and 'zic -L
1148 leapseconds tzdata.zi' can reproduce the tzdata binary files
1149 without and with leap seconds, respectively. To prevent these two
1150 new files from being installed, use 'make TZDATA_TEXT=', and to
1151 suppress leap seconds from the tzdata text installation, use 'make
1152 TZDATA_TEXT=tzdata.zi'.
1154 'make BACKWARD=' now suppresses backward-compatibility names
1155 like 'US/Pacific' that are defined in the 'backward' and
1158 'make check' now works on systems that lack a UTF-8 locale,
1159 or that lack the nsgmls program. Set UTF8_LOCALE to configure
1160 the name of a UTF-8 locale, if you have one.
1162 Y2K runtime checks are no longer enabled by default. Add
1163 -DDEPRECATE_TWO_DIGIT_YEARS to CFLAGS to enable them, instead of
1164 adding -DNO_RUN_TIME_WARNINGS_ABOUT_YEAR_2000_PROBLEMS_THANK_YOU
1165 to disable them. (New name suggested by Brian Inglis.)
1167 The build procedure for zdump now works on AIX 7.1.
1168 (Problem reported by Kees Dekker.)
1172 zic and the reference runtime now reject multiple leap seconds
1173 within 28 days of each other, or leap seconds before the Epoch.
1174 As a result, support for double leap seconds, which was
1175 obsolescent and undocumented, has been removed. Double leap
1176 seconds were an error in the C89 standard; they have never existed
1177 in civil timekeeping. (Thanks to Robert Elz and Bradley White for
1178 noticing glitches in the code that uncovered this problem.)
1180 zic now warns about use of the obsolescent and undocumented -y
1181 option, and about use of the obsolescent TYPE field of Rule lines.
1183 zic now allows unambiguous abbreviations like "Sa" and "Su" for
1184 weekdays; formerly it rejected them due to a bug. Conversely, zic
1185 no longer considers non-prefixes to be abbreviations; for example,
1186 it no longer accepts "lF" as an abbreviation for "lastFriday".
1187 Also, zic warns about the undocumented usage with a "last-"
1188 prefix, e.g., "last-Fri".
1190 Similarly, zic now accepts the unambiguous abbreviation "L" for
1191 "Link" in ordinary context and for "Leap" in leap-second context.
1192 Conversely, zic no longer accepts non-prefixes such as "La" as
1193 abbreviations for words like "Leap".
1195 zic no longer accepts leap second lines in ordinary input, or
1196 ordinary lines in leap second input. Formerly, zic sometimes
1197 warned about this undocumented usage and handled it incorrectly.
1199 The new macro HAVE_TZNAME governs whether the tzname external
1200 variable is exported, instead of USG_COMPAT. USG_COMPAT now
1201 governs only the external variables "timezone" and "daylight".
1202 This change is needed because the three variables are not in the
1203 same category: although POSIX requires tzname, it specifies the
1204 other two variables as optional. Also, USG_COMPAT is now 1 or 0:
1205 if not defined, the code attempts to guess it from other macros.
1207 localtime.c and difftime.c no longer require stdio.h, and .c files
1208 other than zic.c no longer require sys/wait.h.
1210 zdump.c no longer assumes snprintf. (Reported by Jonathan Leffler.)
1212 Calculation of time_t extrema works around a bug in GCC 4.8.4
1213 (Reported by Stan Shebs and Joseph Myers.)
1215 zic.c no longer mistranslates formats of line numbers in non-English
1216 locales. (Problem reported by Benno Schulenberg.)
1218 Several minor changes have been made to the code to make it a
1219 bit easier to port to MS-Windows and Solaris. (Thanks to Kees
1220 Dekker for reporting the problems.)
1222 Changes to documentation and commentary
1224 The two new files 'theory.html' and 'calendars' contain the
1225 contents of the removed file 'Theory'. The goal is to document
1226 tzdb theory more accessibly.
1228 The zic man page now documents abbreviation rules.
1230 tz-link.htm now covers how to apply tzdata changes to clients.
1231 (Thanks to Jorge Fábregas for the AIX link.) It also mentions MySQL.
1233 The leap-seconds.list URL has been updated to something that is
1234 more reliable for tzdb. (Thanks to Tim Parenti and Brian Inglis.)
1236 Release 2017b - 2017-03-17 07:30:38 -0700
1238 Briefly: Haiti has resumed DST.
1240 Changes to past and future timestamps
1242 Haiti resumed observance of DST in 2017. (Thanks to Steffen Thorsen.)
1244 Changes to past timestamps
1246 Liberia changed from -004430 to +00 on 1972-01-07, not 1972-05-01.
1248 Use "MMT" to abbreviate Liberia's time zone before 1972, as "-004430"
1249 is one byte over the POSIX limit. (Problem reported by Derick Rethans.)
1253 The reference localtime implementation now falls back on the
1254 current US daylight-saving transition rules rather than the
1255 1987-2006 rules. This fallback occurs only when (1) the TZ
1256 environment variable has a value like "AST4ADT" that asks
1257 for daylight saving time but does not specify the rules, (2) there
1258 is no file by that name, and (3) the TZDEFRULES file cannot be
1259 loaded. (Thanks to Tom Lane.)
1262 Release 2017a - 2017-02-28 00:05:36 -0800
1264 Briefly: Southern Chile moves from -04/-03 to -03, and Mongolia
1267 Changes to future timestamps
1269 Mongolia no longer observes DST. (Thanks to Ganbold Tsagaankhuu.)
1271 Chile's Region of Magallanes moves from -04/-03 to -03 year-round.
1272 Its clocks diverge from America/Santiago starting 2017-05-13 at
1273 23:00, hiving off a new zone America/Punta_Arenas. Although the
1274 Chilean government says this change expires in May 2019, for now
1275 assume it's permanent. (Thanks to Juan Correa and Deborah
1276 Goldsmith.) This also affects Antarctica/Palmer.
1278 Changes to past timestamps
1280 Fix many entries for historical timestamps for Europe/Madrid
1281 before 1979, to agree with tables compiled by Pere Planesas of the
1282 National Astronomical Observatory of Spain. As a side effect,
1283 this changes some timestamps for Africa/Ceuta before 1929, which
1284 are probably guesswork anyway. (Thanks to Steve Allen and
1285 Pierpaolo Bernardi for the heads-ups, and to Michael Deckers for
1286 correcting the 1901 transition.)
1288 Ecuador observed DST from 1992-11-28 to 1993-02-05.
1289 (Thanks to Alois Treindl.)
1291 Asia/Atyrau and Asia/Oral were at +03 (not +04) before 1930-06-21.
1292 (Thanks to Stepan Golosunov.)
1294 Changes to past and future time zone abbreviations
1296 Switch to numeric time zone abbreviations for South America, as
1297 part of the ongoing project of removing invented abbreviations.
1298 This avoids the need to invent an abbreviation for the new Chilean
1299 new zone. Similarly, switch from invented to numeric time zone
1300 abbreviations for Afghanistan, American Samoa, the Azores,
1301 Bangladesh, Bhutan, the British Indian Ocean Territory, Brunei,
1302 Cape Verde, Chatham Is, Christmas I, Cocos (Keeling) Is, Cook Is,
1303 Dubai, East Timor, Eucla, Fiji, French Polynesia, Greenland,
1304 Indochina, Iran, Iraq, Kiribati, Lord Howe, Macquarie, Malaysia,
1305 the Maldives, Marshall Is, Mauritius, Micronesia, Mongolia,
1306 Myanmar, Nauru, Nepal, New Caledonia, Niue, Norfolk I, Palau,
1307 Papua New Guinea, the Philippines, Pitcairn, Qatar, Réunion, St
1308 Pierre & Miquelon, Samoa, Saudi Arabia, Seychelles, Singapore,
1309 Solomon Is, Tokelau, Tuvalu, Wake, Vanuatu, Wallis & Futuna, and
1310 Xinjiang; for 20-minute daylight saving time in Ghana before 1943;
1311 for half-hour daylight saving time in Belize before 1944 and in
1312 the Dominican Republic before 1975; and for Canary Islands before
1313 1946, for Guinea-Bissau before 1975, for Iceland before 1969, for
1314 Indian Summer Time before 1942, for Indonesia before around 1964,
1315 for Kenya before 1960, for Liberia before 1973, for Madeira before
1316 1967, for Namibia before 1943, for the Netherlands in 1937-9, for
1317 Pakistan before 1971, for Western Sahara before 1977, and for
1318 Zaporozhye in 1880-1924.
1320 For Alaska time from 1900 through 1967, instead of "CAT" use the
1321 abbreviation "AST", the abbreviation commonly used at the time
1322 (Atlantic Standard Time had not been standardized yet). Use "AWT"
1323 and "APT" instead of the invented abbreviations "CAWT" and "CAPT".
1325 Use "CST" and "CDT" instead of invented abbreviations for Macau
1326 before 1999 and Taiwan before 1938, and use "JST" instead of the
1327 invented abbreviation "JCST" for Japan and Korea before 1938.
1329 Change to database entry category
1331 Move the Pacific/Johnston link from 'australasia' to 'backward',
1332 since Johnston is now uninhabited.
1336 zic no longer mishandles some transitions in January 2038 when it
1337 attempts to work around Qt bug 53071. This fixes a bug affecting
1338 Pacific/Tongatapu that was introduced in zic 2016e. localtime.c
1339 now contains a workaround, useful when loading a file generated by
1340 a buggy zic. (Problem and localtime.c fix reported by Bradley
1343 zdump -i now outputs non-hour numeric time zone abbreviations
1344 without a colon, e.g., "+0530" rather than "+05:30". This agrees
1345 with zic %z and with common practice, and simplifies auditing of
1348 zdump is now buildable again with -DUSE_LTZ=0.
1349 (Problem reported by Joseph Myers.)
1351 zdump.c now always includes private.h, to avoid code duplication
1352 with private.h. (Problem reported by Kees Dekker.)
1354 localtime.c no longer mishandles early or late timestamps
1355 when TZ is set to a POSIX-style string that specifies DST.
1356 (Problem reported by Kees Dekker.)
1358 date and strftime now cause %z to generate "-0000" instead of
1359 "+0000" when the UT offset is zero and the time zone abbreviation
1362 Changes to documentation and commentary
1364 The 'Theory' file now better documents choice of historical time
1365 zone abbreviations. (Problems reported by Michael Deckers.)
1367 tz-link.htm now covers leap smearing, which is popular in clouds.
1370 Release 2016j - 2016-11-22 23:17:13 -0800
1372 Briefly: Saratov, Russia moves from +03 to +04 on 2016-12-04.
1374 Changes to future timestamps
1376 Saratov, Russia switches from +03 to +04 on 2016-12-04 at 02:00.
1377 This hives off a new zone Europe/Saratov from Europe/Volgograd.
1378 (Thanks to Yuri Konotopov and Stepan Golosunov.)
1380 Changes to past timestamps
1382 The new zone Asia/Atyrau for Atyraū Region, Kazakhstan, is like
1383 Asia/Aqtau except it switched from +05/+06 to +04/+05 in spring
1384 1999, not fall 1994. (Thanks to Stepan Golosunov.)
1386 Changes to past time zone abbreviations
1388 Asia/Gaza and Asia/Hebron now use "EEST", not "EET", to denote
1389 summer time before 1948. The old use of "EET" was a typo.
1393 zic no longer mishandles file systems that lack hard links, fixing
1394 bugs introduced in 2016g. (Problems reported by Tom Lane.)
1395 Also, when the destination already contains symbolic links, zic
1396 should now work better on systems where the 'link' system call
1397 does not follow symbolic links.
1399 Changes to documentation and commentary
1401 tz-link.htm now documents the relationship between release version
1402 numbers and development-repository commit tags. (Suggested by
1405 The 'Theory' file now documents UT.
1407 iso3166.tab now accents "Curaçao", and commentary now mentions
1408 the names "Cabo Verde" and "Czechia". (Thanks to Jiří Boháč.)
1411 Release 2016i - 2016-11-01 23:19:52 -0700
1413 Briefly: Cyprus split into two time zones on 2016-10-30, and Tonga
1414 reintroduces DST on 2016-11-06.
1416 Changes to future timestamps
1418 Pacific/Tongatapu begins DST on 2016-11-06 at 02:00, ending on
1419 2017-01-15 at 03:00. Assume future observances in Tonga will be
1420 from the first Sunday in November through the third Sunday in
1421 January, like Fiji. (Thanks to Pulu ʻAnau.) Switch to numeric
1422 time zone abbreviations for this zone.
1424 Changes to past and future timestamps
1426 Northern Cyprus is now +03 year round, causing a split in Cyprus
1427 time zones starting 2016-10-30 at 04:00. This creates a zone
1428 Asia/Famagusta. (Thanks to Even Scharning and Matt Johnson.)
1430 Antarctica/Casey switched from +08 to +11 on 2016-10-22.
1431 (Thanks to Steffen Thorsen.)
1433 Changes to past timestamps
1435 Several corrections were made for pre-1975 timestamps in Italy.
1436 These affect Europe/Malta, Europe/Rome, Europe/San_Marino, and
1439 First, the 1893-11-01 00:00 transition in Italy used the new UT
1440 offset (+01), not the old (+00:49:56). (Thanks to Michael
1443 Second, rules for daylight saving in Italy were changed to agree
1444 with Italy's National Institute of Metrological Research (INRiM)
1445 except for 1944, as follows (thanks to Pierpaolo Bernardi, Brian
1446 Inglis, and Michael Deckers):
1448 The 1916-06-03 transition was at 24:00, not 00:00.
1450 The 1916-10-01, 1919-10-05, and 1920-09-19 transitions were at
1453 The 1917-09-30 and 1918-10-06 transitions were at 24:00, not
1456 The 1944-09-17 transition was at 03:00, not 01:00. This
1457 particular change is taken from Italian law as INRiM's table,
1458 (which says 02:00) appears to have a typo here. Also, keep the
1459 1944-04-03 transition for Europe/Rome, as Rome was controlled by
1462 The 1967-1970 and 1972-1974 fallback transitions were at 01:00,
1467 The code should now be buildable on AmigaOS merely by setting the
1468 appropriate Makefile variables. (From a patch by Carsten Larsen.)
1471 Release 2016h - 2016-10-19 23:17:57 -0700
1473 Changes to future timestamps
1475 Asia/Gaza and Asia/Hebron end DST on 2016-10-29 at 01:00, not
1476 2016-10-21 at 00:00. (Thanks to Sharef Mustafa.) Predict that
1477 future fall transitions will be on the last Saturday of October
1478 at 01:00, which is consistent with predicted spring transitions
1479 on the last Saturday of March. (Thanks to Tim Parenti.)
1481 Changes to past timestamps
1483 In Turkey, transitions in 1986-1990 were at 01:00 standard time
1484 not at 02:00, and the spring 1994 transition was on March 20, not
1485 March 27. (Thanks to Kıvanç Yazan.)
1487 Changes to past and future time zone abbreviations
1489 Asia/Colombo now uses numeric time zone abbreviations like "+0530"
1490 instead of alphabetic ones like "IST" and "LKT". Various
1491 English-language sources use "IST", "LKT" and "SLST", with no
1492 working consensus. (Usage of "SLST" mentioned by Sadika
1497 zic no longer mishandles relativizing file names when creating
1498 symbolic links like /etc/localtime, when these symbolic links
1499 are outside the usual directory hierarchy. This fixes a bug
1500 introduced in 2016g. (Problem reported by Andreas Stieger.)
1502 Changes to build procedure
1504 New rules 'traditional_tarballs' and 'traditional_signatures' for
1505 building just the traditional-format distribution. (Requested by
1508 The file 'version' is now put into the tzdata tarball too.
1509 (Requested by Howard Hinnant.)
1511 Changes to documentation and commentary
1513 The 'Theory' file now has a section on interface stability.
1514 (Requested by Paul Koning.) It also mentions features like
1515 tm_zone and localtime_rz that have long been supported by the
1518 tz-link.htm has improved coverage of time zone boundaries suitable
1519 for geolocation. (Thanks to heads-ups from Evan Siroky and Matt
1522 The US commentary now mentions Allen and the "day of two noons".
1524 The Fiji commentary mentions the government's 2016-10-03 press
1525 release. (Thanks to Raymond Kumar.)
1528 Release 2016g - 2016-09-13 08:56:38 -0700
1530 Changes to future timestamps
1532 Turkey switched from EET/EEST (+02/+03) to permanent +03,
1533 effective 2016-09-07. (Thanks to Burak AYDIN.) Use "+03" rather
1534 than an invented abbreviation for the new time.
1536 New leap second 2016-12-31 23:59:60 UTC as per IERS Bulletin C 52.
1537 (Thanks to Tim Parenti.)
1539 Changes to past timestamps
1541 For America/Los_Angeles, spring-forward transition times have been
1542 corrected from 02:00 to 02:01 in 1948, and from 02:00 to 01:00 in
1545 For zones using Soviet time on 1919-07-01, transitions to UT-based
1546 time were at 00:00 UT, not at 02:00 local time. The affected
1547 zones are Europe/Kirov, Europe/Moscow, Europe/Samara, and
1548 Europe/Ulyanovsk. (Thanks to Alexander Belopolsky.)
1550 Changes to past and future time zone abbreviations
1552 The Factory zone now uses the time zone abbreviation -00 instead
1553 of a long English-language string, as -00 is now the normal way to
1554 represent an undefined time zone.
1556 Several zones in Antarctica and the former Soviet Union, along
1557 with zones intended for ships at sea that cannot use POSIX TZ
1558 strings, now use numeric time zone abbreviations instead of
1559 invented or obsolete alphanumeric abbreviations. The affected
1560 zones are Antarctica/Casey, Antarctica/Davis,
1561 Antarctica/DumontDUrville, Antarctica/Mawson, Antarctica/Rothera,
1562 Antarctica/Syowa, Antarctica/Troll, Antarctica/Vostok,
1563 Asia/Anadyr, Asia/Ashgabat, Asia/Baku, Asia/Bishkek, Asia/Chita,
1564 Asia/Dushanbe, Asia/Irkutsk, Asia/Kamchatka, Asia/Khandyga,
1565 Asia/Krasnoyarsk, Asia/Magadan, Asia/Omsk, Asia/Sakhalin,
1566 Asia/Samarkand, Asia/Srednekolymsk, Asia/Tashkent, Asia/Tbilisi,
1567 Asia/Ust-Nera, Asia/Vladivostok, Asia/Yakutsk, Asia/Yekaterinburg,
1568 Asia/Yerevan, Etc/GMT-14, Etc/GMT-13, Etc/GMT-12, Etc/GMT-11,
1569 Etc/GMT-10, Etc/GMT-9, Etc/GMT-8, Etc/GMT-7, Etc/GMT-6, Etc/GMT-5,
1570 Etc/GMT-4, Etc/GMT-3, Etc/GMT-2, Etc/GMT-1, Etc/GMT+1, Etc/GMT+2,
1571 Etc/GMT+3, Etc/GMT+4, Etc/GMT+5, Etc/GMT+6, Etc/GMT+7, Etc/GMT+8,
1572 Etc/GMT+9, Etc/GMT+10, Etc/GMT+11, Etc/GMT+12, Europe/Kaliningrad,
1573 Europe/Minsk, Europe/Samara, Europe/Volgograd, and
1574 Indian/Kerguelen. For Europe/Moscow the invented abbreviation MSM
1575 was replaced by +05, whereas MSK and MSD were kept as they are not
1576 our invention and are widely used.
1578 Changes to zone names
1580 Rename Asia/Rangoon to Asia/Yangon, with a backward compatibility link.
1581 (Thanks to David Massoud.)
1585 zic no longer generates binary files containing POSIX TZ-like
1586 strings that disagree with the local time type after the last
1587 explicit transition in the data. This fixes a bug with
1588 Africa/Casablanca and Africa/El_Aaiun in some year-2037 timestamps
1589 on the reference platform. (Thanks to Alexander Belopolsky for
1590 reporting the bug and suggesting a way forward.)
1592 If the installed localtime and/or posixrules files are symbolic
1593 links, zic now keeps them symbolic links when updating them, for
1594 compatibility with platforms like OpenSUSE where other programs
1595 configure these files as symlinks.
1597 zic now avoids hard linking to symbolic links, avoids some
1598 unnecessary mkdir and stat system calls, and uses shorter file
1601 zdump has a new -i option to generate transitions in a
1602 more-compact but still human-readable format. This option is
1603 experimental, and the output format may change in future versions.
1604 (Thanks to Jon Skeet for suggesting that an option was needed,
1605 and thanks to Tim Parenti and Chris Rovick for further comments.)
1607 Changes to build procedure
1609 An experimental distribution format is available, in addition
1610 to the traditional format which will continue to be distributed.
1611 The new format is a tarball tzdb-VERSION.tar.lz with signature
1612 file tzdb-VERSION.tar.lz.asc. It unpacks to a top-level directory
1613 tzdb-VERSION containing the code and data of the traditional
1614 two-tarball format, along with extra data that may be useful.
1615 (Thanks to Antonio Diaz Diaz, Oscar van Vlijmen, and many others
1616 for comments about the experimental format.)
1618 The release version number is now more accurate in the usual case
1619 where releases are built from a Git repository. For example, if
1620 23 commits and some working-file changes have been made since
1621 release 2016g, the version number is now something like
1622 '2016g-23-g50556e3-dirty' instead of the misleading '2016g'.
1623 Tagged releases use the same version number format as before,
1624 e.g., '2016g'. To support the more-accurate version number, its
1625 specification has moved from a line in the Makefile to a new
1626 source file 'version'.
1628 The experimental distribution contains a file to2050.tzs that
1629 contains what should be the output of 'zdump -i -c 2050' on
1630 primary zones. If this file is available, 'make check' now checks
1631 that zdump generates this output.
1633 'make check_web' now works on Fedora-like distributions.
1635 Changes to documentation and commentary
1637 tzfile.5 now documents the new restriction on POSIX TZ-like
1638 strings that is now implemented by zic.
1640 Comments now cite URLs for some 1917-1921 Russian DST decrees.
1641 (Thanks to Alexander Belopolsky.)
1643 tz-link.htm mentions JuliaTime (thanks to Curtis Vogt) and Time4J
1644 (thanks to Meno Hochschild) and ThreeTen-Extra, and its
1645 description of Java 8 has been brought up to date (thanks to
1646 Stephen Colebourne). Its description of local time on Mars has
1647 been updated to match current practice, and URLs have been updated
1648 and some obsolete ones removed.
1651 Release 2016f - 2016-07-05 16:26:51 +0200
1653 Changes affecting future timestamps
1655 The Egyptian government changed its mind on short notice, and
1656 Africa/Cairo will not introduce DST starting 2016-07-07 after all.
1657 (Thanks to Mina Samuel.)
1659 Asia/Novosibirsk switches from +06 to +07 on 2016-07-24 at 02:00.
1660 (Thanks to Stepan Golosunov.)
1662 Changes to past and future timestamps
1664 Asia/Novokuznetsk and Asia/Novosibirsk now use numeric time zone
1665 abbreviations instead of invented ones.
1667 Changes affecting past timestamps
1669 Europe/Minsk's 1992-03-29 spring-forward transition was at 02:00 not 00:00.
1670 (Thanks to Stepan Golosunov.)
1673 Release 2016e - 2016-06-14 08:46:16 -0700
1675 Changes affecting future timestamps
1677 Africa/Cairo observes DST in 2016 from July 7 to the end of October.
1678 Guess October 27 and 24:00 transitions. (Thanks to Steffen Thorsen.)
1679 For future years, guess April's last Thursday to October's last
1680 Thursday except for Ramadan.
1682 Changes affecting past timestamps
1684 Locations while uninhabited now use '-00', not 'zzz', as a
1685 placeholder time zone abbreviation. This is inspired by Internet
1686 RFC 3339 and is more consistent with numeric time zone
1687 abbreviations already used elsewhere. The change affects several
1688 arctic and antarctic locations, e.g., America/Cambridge_Bay before
1689 1920 and Antarctica/Troll before 2005.
1691 Asia/Baku's 1992-09-27 transition from +04 (DST) to +04 (non-DST) was
1692 at 03:00, not 23:00 the previous day. (Thanks to Michael Deckers.)
1696 zic now outputs a dummy transition at time 2**31 - 1 in zones
1697 whose POSIX-style TZ strings contain a '<'. This mostly works
1698 around Qt bug 53071 <https://bugreports.qt.io/browse/QTBUG-53071>.
1699 (Thanks to Zhanibek Adilbekov for reporting the Qt bug.)
1701 Changes affecting documentation and commentary
1703 tz-link.htm says why governments should give plenty of notice for
1704 time zone or DST changes, and refers to Matt Johnson's blog post.
1706 tz-link.htm mentions Tzdata for Elixir. (Thanks to Matt Johnson.)
1709 Release 2016d - 2016-04-17 22:50:29 -0700
1711 Changes affecting future timestamps
1713 America/Caracas switches from -0430 to -04 on 2016-05-01 at 02:30.
1714 (Thanks to Alexander Krivenyshev for the heads-up.)
1716 Asia/Magadan switches from +10 to +11 on 2016-04-24 at 02:00.
1717 (Thanks to Alexander Krivenyshev and Matt Johnson.)
1719 New zone Asia/Tomsk, split off from Asia/Novosibirsk. It covers
1720 Tomsk Oblast, Russia, which switches from +06 to +07 on 2016-05-29
1721 at 02:00. (Thanks to Stepan Golosunov.)
1723 Changes affecting past timestamps
1725 New zone Europe/Kirov, split off from Europe/Volgograd. It covers
1726 Kirov Oblast, Russia, which switched from +04/+05 to +03/+04 on
1727 1989-03-26 at 02:00, roughly a year after Europe/Volgograd made
1728 the same change. (Thanks to Stepan Golosunov.)
1730 Russia and nearby locations had daylight-saving transitions on
1731 1992-03-29 at 02:00 and 1992-09-27 at 03:00, instead of on
1732 1992-03-28 at 23:00 and 1992-09-26 at 23:00. (Thanks to Stepan
1735 Many corrections to historical time in Kazakhstan from 1991
1736 through 2005. (Thanks to Stepan Golosunov.) Replace Kazakhstan's
1737 invented time zone abbreviations with numeric abbreviations.
1739 Changes to commentary
1741 Mention Internet RFCs 7808 (TZDIST) and 7809 (CalDAV time zone references).
1744 Release 2016c - 2016-03-23 00:51:27 -0700
1746 Changes affecting future timestamps
1748 Azerbaijan no longer observes DST. (Thanks to Steffen Thorsen.)
1750 Chile reverts from permanent to seasonal DST. (Thanks to Juan
1751 Correa for the heads-up, and to Tim Parenti for corrections.)
1752 Guess that future transitions are August's and May's second
1753 Saturdays at 24:00 mainland time. Also, call the period from
1754 2014-09-07 through 2016-05-14 daylight saving time instead of
1755 standard time, as that seems more appropriate now.
1757 Changes affecting past timestamps
1759 Europe/Kaliningrad and Europe/Vilnius changed from +03/+04 to
1760 +02/+03 on 1989-03-26, not 1991-03-31. Europe/Volgograd changed
1761 from +04/+05 to +03/+04 on 1988-03-27, not 1989-03-26.
1762 (Thanks to Stepan Golosunov.)
1764 Changes to commentary
1766 Several updates and URLs for historical and proposed Russian changes.
1767 (Thanks to Stepan Golosunov, Matt Johnson, and Alexander Krivenyshev.)
1770 Release 2016b - 2016-03-12 17:30:14 -0800
1774 Starting with release 2016b, some data entries cause zic implementations
1775 derived from tz releases 2005j through 2015e to issue warnings like
1776 "time zone abbreviation differs from POSIX standard (+03)".
1777 These warnings should not otherwise affect zic's output and can safely be
1778 ignored on today's platforms, as the warnings refer to a restriction in
1779 POSIX.1-1988 that was removed in POSIX.1-2001. One way to suppress the
1780 warnings is to upgrade to zic derived from tz releases 2015f and later.
1782 Changes affecting future timestamps
1784 New zones Europe/Astrakhan and Europe/Ulyanovsk for Astrakhan and
1785 Ulyanovsk Oblasts, Russia, both of which will switch from +03 to +04 on
1786 2016-03-27 at 02:00 local time. They need distinct zones since their
1787 post-1970 histories disagree. New zone Asia/Barnaul for Altai Krai and
1788 Altai Republic, Russia, which will switch from +06 to +07 on the same date
1789 and local time. The Astrakhan change is already official; the others have
1790 passed the first reading in the State Duma and are extremely likely.
1791 Also, Asia/Sakhalin moves from +10 to +11 on 2016-03-27 at 02:00.
1792 (Thanks to Alexander Krivenyshev for the heads-up, and to Matt Johnson
1793 and Stepan Golosunov for followup.)
1795 As a trial of a new system that needs less information to be made up,
1796 the new zones use numeric time zone abbreviations like "+04"
1797 instead of invented abbreviations like "ASTT".
1799 Haiti will not observe DST in 2016. (Thanks to Jean Antoine via
1802 Palestine's spring-forward transition on 2016-03-26 is at 01:00, not 00:00.
1803 (Thanks to Hannah Kreitem.) Guess future transitions will be March's last
1804 Saturday at 01:00, not March's last Friday at 24:00.
1806 Changes affecting past timestamps
1808 Europe/Chisinau observed DST during 1990, and switched from +04 to
1809 +03 at 1990-05-06 02:00, instead of switching from +03 to +02.
1810 (Thanks to Stepan Golosunov.)
1812 1991 abbreviations in Europe/Samara should be SAMT/SAMST, not
1813 KUYT/KUYST. (Thanks to Stepan Golosunov.)
1817 tzselect's diagnostics and checking, and checktab.awk's checking,
1818 have been improved. (Thanks to J William Piggott.)
1820 tzcode now builds under MinGW. (Thanks to Ian Abbott and Esben Haabendal.)
1822 tzselect now tests Julian-date TZ settings more accurately.
1823 (Thanks to J William Piggott.)
1825 Changes to commentary
1827 Comments in zone tables have been improved. (Thanks to J William Piggott.)
1829 tzselect again limits its menu comments so that menus fit on a
1830 24×80 alphanumeric display.
1832 A new web page tz-how-to.html. (Thanks to Bill Seymour.)
1834 In the Theory file, the description of possible time zone abbreviations in
1835 tzdata has been cleaned up, as the old description was unclear and
1836 inconsistent. (Thanks to Alain Mouette for reporting the problem.)
1839 Release 2016a - 2016-01-26 23:28:02 -0800
1841 Changes affecting future timestamps
1843 America/Cayman will not observe daylight saving this year after all.
1844 Revert our guess that it would. (Thanks to Matt Johnson.)
1846 Asia/Chita switches from +0800 to +0900 on 2016-03-27 at 02:00.
1847 (Thanks to Alexander Krivenyshev.)
1849 Asia/Tehran now has DST predictions for the year 2038 and later,
1850 to be March 21 00:00 to September 21 00:00. This is likely better
1851 than predicting no DST, albeit off by a day every now and then.
1853 Changes affecting past and future timestamps
1855 America/Metlakatla switched from PST all year to AKST/AKDT on
1856 2015-11-01 at 02:00. (Thanks to Steffen Thorsen.)
1858 America/Santa_Isabel has been removed, and replaced with a
1859 backward compatibility link to America/Tijuana. Its contents were
1860 apparently based on a misreading of Mexican legislation.
1862 Changes affecting past timestamps
1864 Asia/Karachi's two transition times in 2002 were off by a minute.
1865 (Thanks to Matt Johnson.)
1867 Changes affecting build procedure
1869 An installer can now combine leap seconds with use of the backzone file,
1870 e.g., with 'make PACKRATDATA=backzone REDO=posix_right zones'.
1871 The old 'make posix_packrat' rule is now marked as obsolescent.
1872 (Thanks to Ian Abbott for an initial implementation.)
1874 Changes affecting documentation and commentary
1876 A new file LICENSE makes it easier to see that the code and data
1877 are mostly public-domain. (Thanks to James Knight.) The three
1878 non-public-domain files now use the current (3-clause) BSD license
1879 instead of older versions of that license.
1881 tz-link.htm mentions the BDE library (thanks to Andrew Paprocki),
1882 CCTZ (thanks to Tim Parenti), TimeJones.com, and has a new section
1883 on editing tz source files (with a mention of Sublime zoneinfo,
1884 thanks to Gilmore Davidson).
1886 The Theory and asia files now mention the 2015 book "The Global
1887 Transformation of Time, 1870-1950", and cite a couple of reviews.
1889 The America/Chicago entry now documents the informal use of US
1890 central time in Fort Pierre, South Dakota. (Thanks to Rick
1891 McDermid, Matt Johnson, and Steve Jones.)
1894 Release 2015g - 2015-10-01 00:39:51 -0700
1896 Changes affecting future timestamps
1898 Turkey's 2015 fall-back transition is scheduled for Nov. 8, not Oct. 25.
1901 Norfolk moves from +1130 to +1100 on 2015-10-04 at 02:00 local time.
1902 (Thanks to Alexander Krivenyshev.)
1904 Fiji's 2016 fall-back transition is scheduled for January 17, not 24.
1905 (Thanks to Ken Rylander.)
1907 Fort Nelson, British Columbia will not fall back on 2015-11-01. It has
1908 effectively been on MST (-0700) since it advanced its clocks on 2015-03-08.
1909 New zone America/Fort_Nelson. (Thanks to Matt Johnson.)
1911 Changes affecting past timestamps
1913 Norfolk observed DST from 1974-10-27 02:00 to 1975-03-02 02:00.
1915 Changes affecting code
1917 localtime no longer mishandles America/Anchorage after 2037.
1918 (Thanks to Bradley White for reporting the bug.)
1920 On hosts with signed 32-bit time_t, localtime no longer mishandles
1921 Pacific/Fiji after 2038-01-16 14:00 UTC.
1923 The localtime module allows the variables 'timezone', 'daylight',
1924 and 'altzone' to be in common storage shared with other modules,
1925 and declares them in case the system <time.h> does not.
1926 (Problems reported by Kees Dekker.)
1928 On platforms with tm_zone, strftime.c now assumes it is not NULL.
1929 This simplifies the code and is consistent with zdump.c.
1930 (Problem reported by Christos Zoulas.)
1932 Changes affecting documentation
1934 The tzfile man page now documents that transition times denote the
1935 starts (not the ends) of the corresponding time periods.
1936 (Ambiguity reported by Bill Seymour.)
1939 Release 2015f - 2015-08-10 18:06:56 -0700
1941 Changes affecting future timestamps
1943 North Korea switches to +0830 on 2015-08-15. (Thanks to Steffen Thorsen.)
1944 The abbreviation remains "KST". (Thanks to Robert Elz.)
1946 Uruguay no longer observes DST. (Thanks to Steffen Thorsen
1949 Changes affecting past and future timestamps
1951 Moldova starts and ends DST at 00:00 UTC, not at 01:00 UTC.
1952 (Thanks to Roman Tudos.)
1954 Changes affecting data format and code
1956 zic's '-y YEARISTYPE' option is no longer documented. The TYPE
1957 field of a Rule line should now be '-'; the old values 'even',
1958 'odd', 'uspres', 'nonpres', 'nonuspres' were already undocumented.
1959 Although the implementation has not changed, these features do not
1960 work in the default installation, they are not used in the data,
1961 and they are now considered obsolescent.
1963 zic now checks that two rules don't take effect at the same time.
1964 (Thanks to Jon Skeet and Arthur David Olson.) Constraints on
1965 simultaneity are now documented.
1967 The two characters '%z' in a zone format now stand for the UT
1968 offset, e.g., '-07' for seven hours behind UT and '+0530' for
1969 five hours and thirty minutes ahead. This better supports time
1970 zone abbreviations conforming to POSIX.1-2001 and later.
1972 Changes affecting installed data files
1974 Comments for America/Halifax and America/Glace_Bay have been improved.
1975 (Thanks to Brian Inglis.)
1977 Data entries have been simplified for Atlantic/Canary, Europe/Simferopol,
1978 Europe/Sofia, and Europe/Tallinn. This yields slightly smaller
1979 installed data files for Europe/Simferopol and Europe/Tallinn.
1980 It does not affect timestamps. (Thanks to Howard Hinnant.)
1982 Changes affecting code
1984 zdump and zic no longer warn about valid time zone abbreviations
1987 Some Visual Studio 2013 warnings have been suppressed.
1988 (Thanks to Kees Dekker.)
1990 'date' no longer sets the time of day and its -a, -d, -n and -t
1991 options have been removed. Long obsolescent, the implementation
1992 of these features had porting problems. Builders no longer need
1993 to configure HAVE_ADJTIME, HAVE_SETTIMEOFDAY, or HAVE_UTMPX_H.
1994 (Thanks to Kees Dekker for pointing out the problem.)
1996 Changes affecting documentation
1998 The Theory file mentions naming issues earlier, as these seem to be
1999 poorly publicized (thanks to Gilmore Davidson for reporting the problem).
2001 tz-link.htm mentions Time Zone Database Parser (thanks to Howard Hinnant).
2003 Mention that Herbert Samuel introduced the term "Summer Time".
2006 Release 2015e - 2015-06-13 10:56:02 -0700
2008 Changes affecting future timestamps
2010 Morocco will suspend DST from 2015-06-14 03:00 through 2015-07-19 02:00,
2011 not 06-13 and 07-18 as we had guessed. (Thanks to Milamber.)
2013 Assume Cayman Islands will observe DST starting next year, using US rules.
2014 Although it isn't guaranteed, it is the most likely.
2016 Changes affecting data format
2018 The file 'iso3166.tab' now uses UTF-8, so that its entries can better
2019 spell the names of Åland Islands, Côte d'Ivoire, and Réunion.
2021 Changes affecting code
2023 When displaying data, tzselect converts it to the current locale's
2024 encoding if the iconv command works. (Problem reported by random832.)
2026 tzselect no longer mishandles Dominica, fixing a bug introduced
2027 in Release 2014f. (Problem reported by Owen Leibman.)
2029 zic -l no longer fails when compiled with -DTZDEFAULT=\"/etc/localtime\".
2030 This fixes a bug introduced in Release 2014f.
2031 (Problem reported by Leonardo Chiquitto.)
2034 Release 2015d - 2015-04-24 08:09:46 -0700
2036 Changes affecting future timestamps
2038 Egypt will not observe DST in 2015 and will consider canceling it
2039 permanently. For now, assume no DST indefinitely.
2040 (Thanks to Ahmed Nazmy and Tim Parenti.)
2042 Changes affecting past timestamps
2044 America/Whitehorse switched from UT -09 to -08 on 1967-05-28, not
2045 1966-07-01. Also, Yukon's time zone history is documented better.
2046 (Thanks to Brian Inglis and Dennis Ferguson.)
2048 Change affecting past and future time zone abbreviations
2050 The abbreviations for Hawaii-Aleutian standard and daylight times
2051 have been changed from HAST/HADT to HST/HDT, as per US Government
2052 Printing Office style. This affects only America/Adak since 1983,
2053 as America/Honolulu was already using the new style.
2055 Changes affecting code
2057 zic has some minor performance improvements.
2060 Release 2015c - 2015-04-11 08:55:55 -0700
2062 Changes affecting future timestamps
2064 Egypt's spring-forward transition is at 24:00 on April's last Thursday,
2065 not 00:00 on April's last Friday. 2015's transition will therefore be on
2066 Thursday, April 30 at 24:00, not Friday, April 24 at 00:00. Similar fixes
2067 apply to 2026, 2037, 2043, etc. (Thanks to Steffen Thorsen.)
2069 Changes affecting past timestamps
2071 The following changes affect some pre-1991 Chile-related timestamps
2072 in America/Santiago, Antarctica/Palmer, and Pacific/Easter.
2074 The 1910 transition was January 10, not January 1.
2076 The 1918 transition was September 10, not September 1.
2078 The UT -04 time observed from 1932 to 1942 is now considered to
2079 be standard time, not year-round DST.
2081 Santiago observed DST (UT -03) from 1946-07-15 through
2082 1946-08-31, then reverted to standard time, then switched to -05
2085 Assume transitions before 1968 were at 00:00, since we have no data
2088 The spring 1988 transition was 1988-10-09, not 1988-10-02.
2089 The fall 1990 transition was 1990-03-11, not 1990-03-18.
2091 Assume no UT offset change for Pacific/Easter on 1890-01-01,
2092 and omit all transitions on Pacific/Easter from 1942 through 1946
2093 since we have no data suggesting that they existed.
2095 One more zone has been turned into a link, as it differed
2096 from an existing zone only for older timestamps. As usual,
2097 this change affects UT offsets in pre-1970 timestamps only.
2098 The zone's old contents have been moved to the 'backzone' file.
2099 The affected zone is America/Montreal.
2101 Changes affecting commentary
2103 Mention the TZUpdater tool.
2105 Mention "The Time Now". (Thanks to Brandon Ramsey.)
2108 Release 2015b - 2015-03-19 23:28:11 -0700
2110 Changes affecting future timestamps
2112 Mongolia will start observing DST again this year, from the last
2113 Saturday in March at 02:00 to the last Saturday in September at 00:00.
2114 (Thanks to Ganbold Tsagaankhuu.)
2116 Palestine will start DST on March 28, not March 27. Also,
2117 correct the fall 2014 transition from September 26 to October 24.
2118 Adjust future predictions accordingly. (Thanks to Steffen Thorsen.)
2120 Changes affecting past timestamps
2122 The 1982 zone shift in Pacific/Easter has been corrected, fixing a 2015a
2123 regression. (Thanks to Stuart Bishop for reporting the problem.)
2125 Some more zones have been turned into links, when they differed
2126 from existing zones only for older timestamps. As usual,
2127 these changes affect UT offsets in pre-1970 timestamps only.
2128 Their old contents have been moved to the 'backzone' file.
2129 The affected zones are: America/Antigua, America/Cayman,
2130 Pacific/Midway, and Pacific/Saipan.
2132 Changes affecting time zone abbreviations
2134 Correct the 1992-2010 DST abbreviation in Volgograd from "MSK" to "MSD".
2137 Changes affecting code
2139 Fix integer overflow bug in reference 'mktime' implementation.
2140 (Problem reported by Jörg Richter.)
2142 Allow -Dtime_tz=time_t compilations, and allow -Dtime_tz=... libraries
2143 to be used in the same executable as standard-library time_t functions.
2144 (Problems reported by Bradley White.)
2146 Changes affecting commentary
2148 Cite the recent Mexican decree changing Quintana Roo's time zone.
2149 (Thanks to Carlos Raúl Perasso.)
2151 Likewise for the recent Chilean decree. (Thanks to Eduardo Romero Urra.)
2153 Update info about Mars time.
2156 Release 2015a - 2015-01-29 22:35:20 -0800
2158 Changes affecting future timestamps
2160 The Mexican state of Quintana Roo, represented by America/Cancun,
2161 will shift from Central Time with DST to Eastern Time without DST
2162 on 2015-02-01 at 02:00. (Thanks to Steffen Thorsen and Gwillim Law.)
2164 Chile will not change clocks in April or thereafter; its new standard time
2165 will be its old daylight saving time. This affects America/Santiago,
2166 Pacific/Easter, and Antarctica/Palmer. (Thanks to Juan Correa.)
2168 New leap second 2015-06-30 23:59:60 UTC as per IERS Bulletin C 49.
2169 (Thanks to Tim Parenti.)
2171 Changes affecting past timestamps
2173 Iceland observed DST in 1919 and 1921, and its 1939 fallback
2174 transition was Oct. 29, not Nov. 29. Remove incorrect data from
2175 Shanks about time in Iceland between 1837 and 1908.
2177 Some more zones have been turned into links, when they differed
2178 from existing zones only for older timestamps. As usual,
2179 these changes affect UT offsets in pre-1970 timestamps only.
2180 Their old contents have been moved to the 'backzone' file.
2181 The affected zones are: Asia/Aden, Asia/Bahrain, Asia/Kuwait,
2184 Changes affecting code
2186 tzalloc now scrubs time zone abbreviations compatibly with the way
2187 that tzset always has, by replacing invalid bytes with '_' and by
2188 shortening too-long abbreviations.
2190 tzselect ports to POSIX awk implementations, no longer mishandles
2191 POSIX TZ settings when GNU awk is used, and reports POSIX TZ
2192 settings to the user. (Thanks to Stefan Kuhn.)
2194 Changes affecting build procedure
2196 'make check' now checks for links to links in the data.
2197 One such link (for Africa/Asmera) has been fixed.
2198 (Thanks to Stephen Colebourne for pointing out the problem.)
2200 Changes affecting commentary
2202 The leapseconds file commentary now mentions the expiration date.
2203 (Problem reported by Martin Burnicki.)
2205 Update Mexican Library of Congress URL.
2208 Release 2014j - 2014-11-10 17:37:11 -0800
2210 Changes affecting current and future timestamps
2212 Turks & Caicos' switch from US eastern time to UT -04 year-round
2213 did not occur on 2014-11-02 at 02:00. It's currently scheduled
2214 for 2015-11-01 at 02:00. (Thanks to Chris Walton.)
2216 Changes affecting past timestamps
2218 Many pre-1989 timestamps have been corrected for Asia/Seoul and
2219 Asia/Pyongyang, based on sources for the Korean-language Wikipedia
2220 entry for time in Korea. (Thanks to Sanghyuk Jung.) Also, no
2221 longer guess that Pyongyang mimicked Seoul time after World War II,
2222 as this is politically implausible.
2224 Some more zones have been turned into links, when they differed
2225 from existing zones only for older timestamps. As usual,
2226 these changes affect UT offsets in pre-1970 timestamps only.
2227 Their old contents have been moved to the 'backzone' file.
2228 The affected zones are: Africa/Addis_Ababa, Africa/Asmara,
2229 Africa/Dar_es_Salaam, Africa/Djibouti, Africa/Kampala,
2230 Africa/Mogadishu, Indian/Antananarivo, Indian/Comoro, and
2233 Changes affecting commentary
2235 The commentary is less enthusiastic about Shanks as a source,
2236 and is more careful to distinguish UT from UTC.
2239 Release 2014i - 2014-10-21 22:04:57 -0700
2241 Changes affecting future timestamps
2243 Pacific/Fiji will observe DST from 2014-11-02 02:00 to 2015-01-18 03:00.
2244 (Thanks to Ken Rylander for the heads-up.) Guess that future
2245 years will use a similar pattern.
2247 A new Zone Pacific/Bougainville, for the part of Papua New Guinea
2248 that plans to switch from UT +10 to +11 on 2014-12-28 at 02:00.
2249 (Thanks to Kiley Walbom for the heads-up.)
2251 Changes affecting time zone abbreviations
2253 Since Belarus is not changing its clocks even though Moscow is,
2254 the time zone abbreviation in Europe/Minsk is changing from FET
2255 to its more-traditional value MSK on 2014-10-26 at 01:00.
2256 (Thanks to Alexander Bokovoy for the heads-up about Belarus.)
2258 The new abbreviation IDT stands for the pre-1976 use of UT +08 in
2259 Indochina, to distinguish it better from ICT (+07).
2261 Changes affecting past timestamps
2263 Many timestamps have been corrected for Asia/Ho_Chi_Minh before 1976
2264 (thanks to Trần Ngọc Quân for an indirect pointer to Trần Tiến Bình's
2265 authoritative book). Asia/Ho_Chi_Minh has been added to
2266 zone1970.tab, to give tzselect users in Vietnam two choices,
2267 since north and south Vietnam disagreed after our 1970 cutoff.
2269 Asia/Phnom_Penh and Asia/Vientiane have been turned into links, as
2270 they differed from existing zones only for older timestamps. As
2271 usual, these changes affect pre-1970 timestamps only. Their old
2272 contents have been moved to the 'backzone' file.
2274 Changes affecting code
2276 The time-related library functions now set errno on failure, and
2277 some crashes in the new tzalloc-related library functions have
2278 been fixed. (Thanks to Christos Zoulas for reporting most of
2279 these problems and for suggesting fixes.)
2281 If USG_COMPAT is defined and the requested timestamp is standard time,
2282 the tz library's localtime and mktime functions now set the extern
2283 variable timezone to a value appropriate for that timestamp; and
2284 similarly for ALTZONE, daylight saving time, and the altzone variable.
2285 This change is a companion to the tzname change in 2014h, and is
2286 designed to make timezone and altzone more compatible with tzname.
2288 The tz library's functions now set errno to EOVERFLOW if they fail
2289 because the result cannot be represented. ctime and ctime_r now
2290 return NULL and set errno when a timestamp is out of range, rather
2291 than having undefined behavior.
2293 Some bugs associated with the new 2014g functions have been fixed.
2294 This includes a bug that largely incapacitated the new functions
2295 time2posix_z and posix2time_z. (Thanks to Christos Zoulas.)
2296 It also includes some uses of uninitialized variables after tzalloc.
2297 The new code uses the standard type 'ssize_t', which the Makefile
2298 now gives porting advice about.
2300 Changes affecting commentary
2302 Updated URLs for NRC Canada (thanks to Matt Johnson and Brian Inglis).
2305 Release 2014h - 2014-09-25 18:59:03 -0700
2307 Changes affecting past timestamps
2309 America/Jamaica's 1974 spring-forward transition was Jan. 6, not Apr. 28.
2311 Shanks says Asia/Novokuznetsk switched from LMT (not "NMT") on 1924-05-01,
2312 not 1920-01-06. The old entry was based on a misinterpretation of Shanks.
2314 Some more zones have been turned into links, when they differed
2315 from existing zones only for older timestamps. As usual,
2316 these changes affect UT offsets in pre-1970 timestamps only.
2317 Their old contents have been moved to the 'backzone' file.
2318 The affected zones are: Africa/Blantyre, Africa/Bujumbura,
2319 Africa/Gaborone, Africa/Harare, Africa/Kigali, Africa/Lubumbashi,
2320 Africa/Lusaka, Africa/Maseru, and Africa/Mbabane.
2322 Changes affecting code
2324 zdump -V and -v now output gmtoff= values on all platforms,
2325 not merely on platforms defining TM_GMTOFF.
2327 The tz library's localtime and mktime functions now set tzname to a value
2328 appropriate for the requested timestamp, and zdump now uses this
2329 on platforms not defining TM_ZONE, fixing a 2014g regression.
2330 (Thanks to Tim Parenti for reporting the problem.)
2332 The tz library no longer sets tzname if localtime or mktime fails.
2334 zdump -c no longer mishandles transitions near year boundaries.
2335 (Thanks to Tim Parenti for reporting the problem.)
2337 An access to uninitialized data has been fixed.
2338 (Thanks to Jörg Richter for reporting the problem.)
2340 When THREAD_SAFE is defined, the code ports to the C11 memory model.
2341 A memory leak has been fixed if ALL_STATE and THREAD_SAFE are defined
2342 and two threads race to initialize data used by gmtime-like functions.
2343 (Thanks to Andy Heninger for reporting the problems.)
2345 Changes affecting build procedure
2347 'make check' now checks better for properly-sorted data.
2349 Changes affecting documentation and commentary
2351 zdump's gmtoff=N output is now documented, and its isdst=D output
2352 is now documented to possibly output D values other than 0 or 1.
2354 zdump -c's treatment of years is now documented to use the
2355 Gregorian calendar and Universal Time without leap seconds,
2356 and its behavior at cutoff boundaries is now documented better.
2357 (Thanks to Arthur David Olson and Tim Parenti for reporting the problems.)
2359 Programs are now documented to use the proleptic Gregorian calendar.
2360 (Thanks to Alan Barrett for the suggestion.)
2362 Fractional-second GMT offsets have been documented for civil time
2363 in 19th-century Chennai, Jakarta, and New York.
2366 Release 2014g - 2014-08-28 12:31:23 -0700
2368 Changes affecting future timestamps
2370 Turks & Caicos is switching from US eastern time to UT -04
2371 year-round, modeled as a switch on 2014-11-02 at 02:00.
2372 [As noted in 2014j, this switch was later delayed.]
2374 Changes affecting past timestamps
2376 Time in Russia or the USSR before 1926 or so has been corrected by
2377 a few seconds in the following zones: Asia/Irkutsk,
2378 Asia/Krasnoyarsk, Asia/Omsk, Asia/Samarkand, Asia/Tbilisi,
2379 Asia/Vladivostok, Asia/Yakutsk, Europe/Riga, Europe/Samara. For
2380 Asia/Yekaterinburg the correction is a few minutes. (Thanks to
2381 Vladimir Karpinsky.)
2383 The Portuguese decree of 1911-05-26 took effect on 1912-01-01.
2384 This affects 1911 timestamps in Africa/Bissau, Africa/Luanda,
2385 Atlantic/Azores, and Atlantic/Madeira. Also, Lisbon's pre-1912
2386 GMT offset was -0:36:45 (rounded from -0:36:44.68), not -0:36:32.
2387 (Thanks to Stephen Colebourne for pointing to the decree.)
2389 Asia/Dhaka ended DST on 2009-12-31 at 24:00, not 23:59.
2391 A new file 'backzone' contains data which may appeal to
2392 connoisseurs of old timestamps, although it is out of scope for
2393 the tz database, is often poorly sourced, and contains some data
2394 that is known to be incorrect. The new file is not recommended
2395 for ordinary use and its entries are not installed by default.
2396 (Thanks to Lester Caine for the high-quality Jersey, Guernsey, and
2397 Isle of Man entries.)
2399 Some more zones have been turned into links, when they differed
2400 from existing zones only for older timestamps. As usual,
2401 these changes affect UT offsets in pre-1970 timestamps only.
2402 Their old contents have been moved to the 'backzone' file.
2403 The affected zones are: Africa/Bangui, Africa/Brazzaville,
2404 Africa/Douala, Africa/Kinshasa, Africa/Libreville, Africa/Luanda,
2405 Africa/Malabo, Africa/Niamey, and Africa/Porto-Novo.
2407 Changes affecting code
2409 Unless NETBSD_INSPIRED is defined to 0, the tz library now
2410 supplies functions for creating and using objects that represent
2411 timezones. The new functions are tzalloc, tzfree, localtime_rz,
2412 mktime_z, and (if STD_INSPIRED is also defined) posix2time_z and
2413 time2posix_z. They are intended for performance: for example,
2414 localtime_rz (unlike localtime_r) is trivially thread-safe without
2415 locking. (Thanks to Christos Zoulas for proposing NetBSD-inspired
2416 functions, and to Alan Barrett and Jonathan Lennox for helping to
2419 zdump now builds with the tz library unless USE_LTZ is defined to 0,
2420 This lets zdump use tz features even if the system library lacks them.
2421 To build zdump with the system library, use 'make CFLAGS=-DUSE_LTZ=0
2422 TZDOBJS=zdump.o CHECK_TIME_T_ALTERNATIVES='.
2424 zdump now uses localtime_rz if available, as it's significantly faster,
2425 and it can help zdump better diagnose invalid timezone names.
2426 Define HAVE_LOCALTIME_RZ to 0 to suppress this. HAVE_LOCALTIME_RZ
2427 defaults to 1 if NETBSD_INSPIRED && USE_LTZ. When localtime_rz is
2428 not available, zdump now uses localtime_r and tzset if available,
2429 as this is a bit cleaner and faster than plain localtime. Compile
2430 with -DHAVE_LOCALTIME_R=0 and/or -DHAVE_TZSET=0 if your system
2431 lacks these two functions.
2433 If THREAD_SAFE is defined to 1, the tz library is now thread-safe.
2434 Although not needed for tz's own applications, which are single-threaded,
2435 this supports POSIX better if the tz library is used in multithreaded apps.
2437 Some crashes have been fixed when zdump or the tz library is given
2438 invalid or outlandish input.
2440 The tz library no longer mishandles leap seconds on platforms with
2441 unsigned time_t in timezones that lack ordinary transitions after 1970.
2443 The tz code now attempts to infer TM_GMTOFF and TM_ZONE if not
2444 already defined, to make it easier to configure on common platforms.
2445 Define NO_TM_GMTOFF and NO_TM_ZONE to suppress this.
2447 Unless the new macro UNINIT_TRAP is defined to 1, the tz code now
2448 assumes that reading uninitialized memory yields garbage values
2449 but does not cause other problems such as traps.
2451 If TM_GMTOFF is defined and UNINIT_TRAP is 0, mktime is now
2452 more likely to guess right for ambiguous timestamps near
2453 transitions where tm_isdst does not change.
2455 If HAVE_STRFTIME_L is defined to 1, the tz library now defines
2456 strftime_l for compatibility with recent versions of POSIX.
2457 Only the C locale is supported, though. HAVE_STRFTIME_L defaults
2458 to 1 on recent POSIX versions, and to 0 otherwise.
2460 tzselect -c now uses a hybrid distance measure that works better
2461 in Africa. (Thanks to Alan Barrett for noting the problem.)
2463 The C source code now ports to NetBSD when GCC_DEBUG_FLAGS is used,
2464 or when time_tz is defined.
2466 When HAVE_UTMPX_H is set the 'date' command now builds on systems
2467 whose <utmpx.h> file does not define WTMPX_FILE, and when setting
2468 the date it updates the wtmpx file if _PATH_WTMPX is defined.
2469 This affects GNU/Linux and similar systems.
2471 For easier maintenance later, some C code has been simplified,
2472 some lint has been removed, and the code has been tweaked so that
2473 plain 'make' is more likely to work.
2475 The C type 'bool' is now used for boolean values, instead of 'int'.
2477 The long-obsolete LOCALE_HOME code has been removed.
2479 The long-obsolete 'gtime' function has been removed.
2481 Changes affecting build procedure
2483 'zdump' no longer links in ialloc.o, as it's not needed.
2485 'make check_time_t_alternatives' no longer assumes GNU diff.
2487 Changes affecting distribution tarballs
2489 The files checktab.awk and zoneinfo2tdf.pl are now distributed in
2490 the tzdata tarball instead of the tzcode tarball, since they help
2491 maintain the data. The NEWS and Theory files are now also
2492 distributed in the tzdata tarball, as they're relevant for data.
2493 (Thanks to Alan Barrett for pointing this out.) Also, the
2494 leapseconds.awk file is no longer distributed in the tzcode
2495 tarball, since it belongs in the tzdata tarball (where 2014f
2496 inadvertently also distributed it).
2498 Changes affecting documentation and commentary
2500 A new file CONTRIBUTING is distributed. (Thanks to Tim Parenti for
2501 suggesting a CONTRIBUTING file, and to Tony Finch and Walter Harms
2504 The man pages have been updated to use function prototypes,
2505 to document thread-safe variants like localtime_r, and to document
2506 the NetBSD-inspired functions tzalloc, tzfree, localtime_rz, and
2509 The fields in Link lines have been renamed to be more descriptive
2510 and more like the parameters of 'ln'. LINK-FROM has become TARGET,
2511 and LINK-TO has become LINK-NAME.
2513 tz-link.htm mentions the IETF's tzdist working group; Windows
2514 Runtime etc. (thanks to Matt Johnson); and HP-UX's tztab.
2516 Some broken URLs have been fixed in the commentary. (Thanks to
2519 Commentary about Philippines DST has been updated, and commentary
2520 on pre-1970 time in India has been added.
2523 Release 2014f - 2014-08-05 17:42:36 -0700
2525 Changes affecting future timestamps
2527 Russia will subtract an hour from most of its time zones on 2014-10-26
2528 at 02:00 local time. (Thanks to Alexander Krivenyshev.)
2529 There are a few exceptions: Magadan Oblast (Asia/Magadan) and Zabaykalsky
2530 Krai are subtracting two hours; conversely, Chukotka Autonomous Okrug
2531 (Asia/Anadyr), Kamchatka Krai (Asia/Kamchatka), Kemerovo Oblast
2532 (Asia/Novokuznetsk), and the Samara Oblast and the Udmurt Republic
2533 (Europe/Samara) are not changing their clocks. The changed zones are
2534 Europe/Kaliningrad, Europe/Moscow, Europe/Simferopol, Europe/Volgograd,
2535 Asia/Yekaterinburg, Asia/Omsk, Asia/Novosibirsk, Asia/Krasnoyarsk,
2536 Asia/Irkutsk, Asia/Yakutsk, Asia/Vladivostok, Asia/Khandyga,
2537 Asia/Sakhalin, and Asia/Ust-Nera; Asia/Magadan will have two hours
2538 subtracted; and Asia/Novokuznetsk's time zone abbreviation is affected,
2539 but not its UTC offset. Two zones are added: Asia/Chita (split
2540 from Asia/Yakutsk, and also with two hours subtracted) and
2541 Asia/Srednekolymsk (split from Asia/Magadan, but with only one hour
2542 subtracted). (Thanks to Tim Parenti for much of the above.)
2544 Changes affecting time zone abbreviations
2546 Australian eastern time zone abbreviations are now AEST/AEDT not EST,
2547 and similarly for the other Australian zones. That is, for eastern
2548 standard and daylight saving time the abbreviations are AEST and AEDT
2549 instead of the former EST for both; similarly, ACST/ACDT, ACWST/ACWDT,
2550 and AWST/AWDT are now used instead of the former CST, CWST, and WST.
2551 This change does not affect UT offsets, only time zone abbreviations.
2552 (Thanks to Rich Tibbett and many others.)
2554 Asia/Novokuznetsk shifts from NOVT to KRAT (remaining on UT +07)
2555 effective 2014-10-26 at 02:00 local time.
2557 The time zone abbreviation for Xinjiang Time (observed in Ürümqi)
2558 has been changed from URUT to XJT. (Thanks to Luther Ma.)
2560 Prefer MSK/MSD for Moscow time in Russia, even in other cities.
2561 Similarly, prefer EET/EEST for eastern European time in Russia.
2563 Change time zone abbreviations in (western) Samoa to use "ST" and
2564 "DT" suffixes, as this is more likely to match common practice.
2565 Prefix "W" to (western) Samoa time when its standard-time offset
2566 disagrees with that of American Samoa.
2568 America/Metlakatla now uses PST, not MeST, to abbreviate its time zone.
2570 Time zone abbreviations have been updated for Japan's two time
2571 zones used 1896-1937. JWST now stands for Western Standard
2572 Time, and JCST for Central Standard Time (formerly this was CJT).
2573 These abbreviations are now used for time in Korea, Taiwan,
2574 and Sakhalin while controlled by Japan.
2576 Changes affecting past timestamps
2578 China's five zones have been simplified to two, since the post-1970
2579 differences in the other three seem to have been imaginary. The
2580 zones Asia/Harbin, Asia/Chongqing, and Asia/Kashgar have been
2581 removed; backwards-compatibility links still work, albeit with
2582 different behaviors for timestamps before May 1980. Asia/Urumqi's
2583 1980 transition to UT +08 has been removed, so that it is now at
2584 +06 and not +08. (Thanks to Luther Ma and to Alois Treindl;
2585 Treindl sent helpful translations of two papers by Guo Qingsheng.)
2587 Some zones have been turned into links, when they differed from existing
2588 zones only for older UT offsets where data entries were likely invented.
2589 These changes affect UT offsets in pre-1970 timestamps only. This is
2590 similar to the change in release 2013e, except this time for western
2591 Africa. The affected zones are: Africa/Bamako, Africa/Banjul,
2592 Africa/Conakry, Africa/Dakar, Africa/Freetown, Africa/Lome,
2593 Africa/Nouakchott, Africa/Ouagadougou, Africa/Sao_Tome, and
2594 Atlantic/St_Helena. This also affects the backwards-compatibility
2595 link Africa/Timbuktu. (Thanks to Alan Barrett, Stephen Colebourne,
2596 Tim Parenti, and David Patte for reporting problems in earlier
2597 versions of this change.)
2599 Asia/Shanghai's pre-standard-time UT offset has been changed from
2600 8:05:57 to 8:05:43, the location of Xujiahui Observatory. Its
2601 transition to standard time has been changed from 1928 to 1901.
2603 Asia/Taipei switched to JWST on 1896-01-01, then to JST on 1937-10-01,
2604 then to CST on 1945-09-21 at 01:00, and did not observe DST in 1945.
2605 In 1946 it observed DST from 05-15 through 09-30; in 1947
2606 from 04-15 through 10-31; and in 1979 from 07-01 through 09-30.
2607 (Thanks to Yu-Cheng Chuang.)
2609 Asia/Riyadh's transition to standard time is now 1947-03-14, not 1950.
2611 Europe/Helsinki's 1942 fall-back transition was 10-04 at 01:00, not
2612 10-03 at 00:00. (Thanks to Konstantin Hyppönen.)
2614 Pacific/Pago_Pago has been changed from UT -11:30 to -11 for the
2615 period from 1911 to 1950.
2617 Pacific/Chatham has been changed to New Zealand standard time plus
2618 45 minutes for the period before 1957, reflecting a 1956 remark in
2619 the New Zealand parliament.
2621 Europe/Budapest has several pre-1946 corrections: in 1918 the transition
2622 out of DST was on 09-16, not 09-29; in 1919 it was on 11-24, not 09-15; in
2623 1945 it was on 11-01, not 11-03; in 1941 the transition to DST was 04-08
2624 not 04-06 at 02:00; and there was no DST in 1920.
2626 Africa/Accra is now assumed to have observed DST from 1920 through 1935.
2628 Time in Russia before 1927 or so has been corrected by a few seconds in
2629 the following zones: Europe/Moscow, Asia/Irkutsk, Asia/Tbilisi,
2630 Asia/Tashkent, Asia/Vladivostok, Asia/Yekaterinburg, Europe/Helsinki, and
2631 Europe/Riga. Also, Moscow's location has been changed to its Kilometer 0
2632 point. (Thanks to Vladimir Karpinsky for the Moscow changes.)
2634 Changes affecting data format
2636 A new file 'zone1970.tab' supersedes 'zone.tab' in the installed data.
2637 The new file's extended format allows multiple country codes per zone.
2638 The older file is still installed but is deprecated; its format is
2639 not changing and it will still be distributed for a while, but new
2640 applications should use the new file.
2642 The new file format simplifies maintenance of obscure locations.
2643 To test this, it adds coverage for the Crozet Islands and the
2644 Scattered Islands. (Thanks to Tobias Conradi and Antoine Leca.)
2646 The file 'iso3166.tab' is planned to switch from ASCII to UTF-8.
2647 It is still ASCII now, but commentary about the switch has been added.
2648 The new file 'zone1970.tab' already uses UTF-8.
2650 Changes affecting code
2652 'localtime', 'mktime', etc. now use much less stack space if ALL_STATE
2653 is defined. (Thanks to Elliott Hughes for reporting the problem.)
2655 'zic' no longer mishandles input when ignoring case in locales that
2656 are not compatible with English, e.g., unibyte Turkish locales when
2657 compiled with HAVE_GETTEXT.
2659 Error diagnostics of 'zic' and 'yearistype' have been reworded so that
2660 they no longer use ASCII '-' as if it were a dash.
2662 'zic' now rejects output file names that contain '.' or '..' components.
2663 (Thanks to Tim Parenti for reporting the problem.)
2665 'zic -v' now warns about output file names that do not follow
2666 POSIX rules, or that contain a digit or '.'. (Thanks to Arthur
2667 David Olson for starting the ball rolling on this.)
2669 Some lint has been removed when using GCC_DEBUG_FLAGS with GCC 4.9.0.
2671 Changes affecting build procedure
2673 'zic' no longer links in localtime.o and asctime.o, as they're not needed.
2674 (Thanks to John Cochran.)
2676 Changes affecting documentation and commentary
2678 The 'Theory' file documents legacy names, the longstanding
2679 exceptions to the POSIX-inspired file name rules.
2681 The 'zic' documentation clarifies the role of time types when
2682 interpreting dates. (Thanks to Arthur David Olson.)
2684 Documentation and commentary now prefer UTF-8 to US-ASCII,
2685 allowing the use of proper accents in foreign words and names.
2686 Code and data have not changed because of this. (Thanks to
2687 Garrett Wollman, Ian Abbott, and Guy Harris for helping to debug
2690 Non-HTML documentation and commentary now use plain-text URLs instead of
2691 HTML insertions, and are more consistent about bracketing URLs when they
2692 are not already surrounded by white space. (Thanks to suggestions by
2695 There is new commentary about Xujiahui Observatory, the five time-zone
2696 project in China from 1918 to 1949, timekeeping in Japanese-occupied
2697 Shanghai, and Tibet Time in the 1950s. The sharp-eyed can spot the
2698 warlord Jin Shuren in the data.
2700 Commentary about the coverage of each Russian zone has been standardized.
2701 (Thanks to Tim Parenti.)
2703 There is new commentary about contemporary timekeeping in Ethiopia.
2705 Obsolete comments about a 2007 proposal for DST in Kuwait has been removed.
2707 There is new commentary about time in Poland in 1919.
2709 Proper credit has been given to DST inventor George Vernon Hudson.
2711 Commentary about time in Metlakatla, AK and Resolute, NU has been
2712 improved, with a new source for the former.
2714 In zone.tab, Pacific/Easter no longer mentions Salas y Gómez, as it
2717 Commentary about permanent Antarctic bases has been updated.
2719 Several typos have been corrected. (Thanks to Tim Parenti for
2720 contributing some of these fixes.)
2722 tz-link.htm now mentions the JavaScript libraries Moment Timezone,
2723 TimezoneJS.Date, Walltime-js, and Timezone. (Thanks to a heads-up
2724 from Matt Johnson.) Also, it mentions the Go 'latlong' package.
2725 (Thanks to a heads-up from Dirkjan Ochtman.)
2727 The files usno1988, usno1989, usno1989a, usno1995, usno1997, and usno1998
2728 have been removed. These obsolescent US Naval Observatory entries were no
2729 longer helpful for maintenance. (Thanks to Tim Parenti for the suggestion.)
2732 Release 2014e - 2014-06-12 21:53:52 -0700
2734 Changes affecting near-future timestamps
2736 Egypt's 2014 Ramadan-based transitions are June 26 and July 31 at 24:00.
2737 (Thanks to Imed Chihi.) Guess that from 2015 on Egypt will temporarily
2738 switch to standard time at 24:00 the last Thursday before Ramadan, and
2739 back to DST at 00:00 the first Friday after Ramadan.
2741 Similarly, Morocco's are June 28 at 03:00 and August 2 at 02:00. (Thanks
2742 to Milamber Space Network.) Guess that from 2015 on Morocco will
2743 temporarily switch to standard time at 03:00 the last Saturday before
2744 Ramadan, and back to DST at 02:00 the first Saturday after Ramadan.
2746 Changes affecting past timestamps
2748 The abbreviation "MSM" (Moscow Midsummer Time) is now used instead of
2749 "MSD" for Moscow's double daylight time in summer 1921. Also, a typo
2750 "VLASST" has been repaired to be "VLAST" for Vladivostok summer time
2751 in 1991. (Thanks to Hank W. for reporting the problems.)
2753 Changes affecting commentary
2755 tz-link.htm now cites RFC 7265 for jCal, mentions PTP and the
2756 draft CalDAV extension, updates URLs for TSP, TZInfo, IATA, and
2757 removes stale pointers to World Time Explorer and WORLDTIME.
2760 Release 2014d - 2014-05-27 21:34:40 -0700
2762 Changes affecting code
2764 zic no longer generates files containing timestamps before the Big Bang.
2765 This works around GNOME glib bug 878
2766 <https://gitlab.gnome.org/GNOME/glib/issues/878>
2767 (Thanks to Leonardo Chiquitto for reporting the bug, and to
2768 Arthur David Olson and James Cloos for suggesting improvements to the fix.)
2770 Changes affecting documentation
2772 tz-link.htm now mentions GNOME.
2775 Release 2014c - 2014-05-13 07:44:13 -0700
2777 Changes affecting near-future timestamps
2779 Egypt observes DST starting 2014-05-15 at 24:00.
2780 (Thanks to Ahmad El-Dardiry and Gunther Vermier.)
2781 Details have not been announced, except that DST will not be observed
2782 during Ramadan. Guess that DST will stop during the same Ramadan dates as
2783 Morocco, and that Egypt's future spring and fall transitions will be the
2784 same as 2010 when it last observed DST, namely April's last Friday at
2785 00:00 to September's last Thursday at 23:00 standard time. Also, guess
2786 that Ramadan transitions will be at 00:00 standard time.
2788 Changes affecting code
2790 zic now generates transitions for minimum time values, eliminating guesswork
2791 when handling low-valued timestamps. (Thanks to Arthur David Olson.)
2793 Port to Cygwin sans glibc. (Thanks to Arthur David Olson.)
2795 Changes affecting commentary and documentation
2797 Remove now-confusing comment about Jordan. (Thanks to Oleksii Nochovnyi.)
2800 Release 2014b - 2014-03-24 21:28:50 -0700
2802 Changes affecting near-future timestamps
2804 Crimea switches to Moscow time on 2014-03-30 at 02:00 local time.
2805 (Thanks to Alexander Krivenyshev.) Move its zone.tab entry from UA to RU.
2807 New entry for Troll station, Antarctica. (Thanks to Paul-Inge Flakstad and
2808 Bengt-Inge Larsson.) This is currently an approximation; a better version
2809 will require the zic and localtime fixes mentioned below, and the plan is
2810 to wait for a while until at least the zic fixes propagate.
2812 Changes affecting code
2814 'zic' and 'localtime' no longer reject locations needing four transitions
2815 per year for the foreseeable future. (Thanks to Andrew Main (Zefram).)
2816 Also, 'zic' avoids some unlikely failures due to integer overflow.
2818 Changes affecting build procedure
2820 'make check' now detects Rule lines defined but never used.
2821 The NZAQ rules, an instance of this problem, have been removed.
2823 Changes affecting commentary and documentation
2825 Fix Tuesday/Thursday typo in description of time in Israel.
2826 (Thanks to Bert Katz via Pavel Kharitonov and Mike Frysinger.)
2828 Microsoft Windows 8.1 doesn't support tz database names. (Thanks
2829 to Donald MacQueen.) Instead, the Microsoft Windows Store app
2830 library supports them.
2832 Add comments about Johnston Island time in the 1960s.
2833 (Thanks to Lyle McElhaney.)
2835 Morocco's 2014 DST start will be as predicted.
2836 (Thanks to Sebastien Willemijns.)
2839 Release 2014a - 2014-03-07 23:30:29 -0800
2841 Changes affecting near-future timestamps
2843 Turkey begins DST on 2014-03-31, not 03-30. (Thanks to Faruk Pasin for
2844 the heads-up, and to Tim Parenti for simplifying the update.)
2846 Changes affecting past timestamps
2848 Fiji ended DST on 2014-01-19 at 02:00, not the previously-scheduled 03:00.
2849 (Thanks to Steffen Thorsen.)
2851 Ukraine switched from Moscow to Eastern European time on 1990-07-01
2852 (not 1992-01-01), and observed DST during the entire next winter.
2853 (Thanks to Vladimir in Moscow via Alois Treindl.)
2855 In 1988 Israel observed DST from 04-10 to 09-04, not 04-09 to 09-03.
2856 (Thanks to Avigdor Finkelstein.)
2858 Changes affecting code
2860 A uninitialized-storage bug in 'localtime' has been fixed.
2861 (Thanks to Logan Chien.)
2863 Changes affecting the build procedure
2865 The settings for 'make check_web' now default to Ubuntu 13.10.
2867 Changes affecting commentary and documentation
2869 The boundary of the US Pacific time zone is given more accurately.
2870 (Thanks to Alan Mintz.)
2872 Chile's 2014 DST will be as predicted. (Thanks to José Miguel Garrido.)
2874 Paraguay's 2014 DST will be as predicted. (Thanks to Carlos Raúl Perasso.)
2876 Better descriptions of countries with same time zone history as
2877 Trinidad and Tobago since 1970. (Thanks to Alan Barrett for suggestion.)
2879 Several changes affect tz-link.htm, the main web page.
2881 Mention Time.is (thanks to Even Scharning) and WX-now (thanks to
2884 Mention xCal (Internet RFC 6321) and jCal.
2886 Microsoft has some support for tz database names.
2888 CLDR data formats include both XML and JSON.
2890 Mention Maggiolo's map of solar vs standard time.
2891 (Thanks to Arthur David Olson.)
2893 Mention TZ4Net. (Thanks to Matt Johnson.)
2895 Mention the timezone-olson Haskell package.
2897 Mention zeitverschiebung.net. (Thanks to Martin Jäger.)
2899 Remove moribund links to daylight-savings-time.info and to
2900 Simple Timer + Clocks.
2902 Update two links. (Thanks to Oscar van Vlijmen.)
2904 Fix some formatting glitches, e.g., remove random newlines from
2905 abbr elements' title attributes.
2908 Release 2013i - 2013-12-17 07:25:23 -0800
2910 Changes affecting near-future timestamps:
2912 Jordan switches back to standard time at 00:00 on December 20, 2013.
2913 The 2006-2011 transition schedule is planned to resume in 2014.
2914 (Thanks to Steffen Thorsen.)
2916 Changes affecting past timestamps:
2918 In 2004, Cuba began DST on March 28, not April 4.
2919 (Thanks to Steffen Thorsen.)
2921 Changes affecting code
2923 The compile-time flag NOSOLAR has been removed, as nowadays the
2924 benefit of slightly shrinking runtime table size is outweighed by the
2925 cost of disallowing potential future updates that exceed old limits.
2927 Changes affecting documentation and commentary
2929 The files solar87, solar88, and solar89 are no longer distributed.
2930 They were a negative experiment - that is, a demonstration that
2931 tz data can represent solar time only with some difficulty and error.
2932 Their presence in the distribution caused confusion, as Riyadh
2933 civil time was generally not solar time in those years.
2935 tz-link.htm now mentions Noda Time. (Thanks to Matt Johnson.)
2938 Release 2013h - 2013-10-25 15:32:32 -0700
2940 Changes affecting current and future timestamps:
2942 Libya has switched its UT offset back to +02 without DST, instead
2943 of +01 with DST. (Thanks to Even Scharning.)
2945 Western Sahara (Africa/El_Aaiun) uses Morocco's DST rules.
2946 (Thanks to Gwillim Law.)
2948 Changes affecting future timestamps:
2950 Acre and (we guess) western Amazonas will switch from UT -04 to -05
2951 on 2013-11-10. This affects America/Rio_Branco and America/Eirunepe.
2952 (Thanks to Steffen Thorsen.)
2954 Add entries for DST transitions in Morocco in the year 2038.
2955 This avoids some year-2038 glitches introduced in 2013g.
2956 (Thanks to Yoshito Umaoka for reporting the problem.)
2958 Changes affecting API
2960 The 'tzselect' command no longer requires the 'select' command,
2961 and should now work with /bin/sh on more platforms. It also works
2962 around a bug in BusyBox awk before version 1.21.0. (Thanks to
2963 Patrick 'P. J.' McDermott and Alan Barrett.)
2965 Changes affecting code
2967 Fix localtime overflow bugs with 32-bit unsigned time_t.
2969 zdump no longer assumes sscanf returns maximal values on overflow.
2971 Changes affecting the build procedure
2973 The builder can specify which programs to use, if any, instead of
2974 'ar' and 'ranlib', and libtz.a is now built locally before being
2975 installed. (Thanks to Michael Forney.)
2977 A dependency typo in the 'zdump' rule has been fixed.
2978 (Thanks to Andrew Paprocki.)
2980 The Makefile has been simplified by assuming that 'mkdir -p' and 'cp -f'
2981 work as specified by POSIX.2-1992 or later; this is portable nowadays.
2983 'make clean' no longer removes 'leapseconds', since it's
2984 host-independent and is part of the distribution.
2986 The unused makefile macros TZCSRCS, TZDSRCS, DATESRCS have been removed.
2988 Changes affecting documentation and commentary
2990 tz-link.htm now mentions TC TIMEZONE's draft time zone service protocol
2991 (thanks to Mike Douglass) and TimezoneJS.Date (thanks to Jim Fehrle).
2993 Update URLs in tz-link page. Add URLs for Microsoft Windows, since
2994 8.1 introduces tz support. Remove URLs for Tru64 and UnixWare (no
2995 longer maintained) and for old advisories. SOFA now does C.
2997 Release 2013g - 2013-09-30 21:08:26 -0700
2999 Changes affecting current and near-future timestamps
3001 Morocco now observes DST from the last Sunday in March to the last
3002 Sunday in October, not April to September respectively. (Thanks
3003 to Steffen Thorsen.)
3005 Changes affecting 'zic'
3007 'zic' now runs on platforms that lack both hard links and symlinks.
3008 (Thanks to Theo Veenker for reporting the problem, for MinGW.)
3009 Also, fix some bugs on platforms that lack hard links but have symlinks.
3011 'zic -v' again warns that Asia/Tehran has no POSIX environment variable
3012 to predict the far future, fixing a bug introduced in 2013e.
3014 Changes affecting the build procedure
3016 The 'leapseconds' file is again put into the tzdata tarball.
3017 Also, 'leapseconds.awk', so tzdata is self-contained. (Thanks to
3018 Matt Burgess and Ian Abbott.) The timestamps of these and other
3019 dependent files in tarballs are adjusted more consistently.
3021 Changes affecting documentation and commentary
3023 The README file is now part of the data tarball as well as the code.
3024 It now states that files are public domain unless otherwise specified.
3025 (Thanks to Andrew Main (Zefram) for asking for clarifications.)
3026 Its details about the 1989 release moved to a place of honor near
3030 Release 2013f - 2013-09-24 23:37:36 -0700
3032 Changes affecting near-future timestamps
3034 Tocantins will very likely not observe DST starting this spring.
3035 (Thanks to Steffen Thorsen.)
3037 Jordan will likely stay at UT +03 indefinitely, and will not fall
3040 Palestine will fall back at 00:00, not 01:00. (Thanks to Steffen Thorsen.)
3042 Changes affecting API
3044 The types of the global variables 'timezone' and 'altzone' (if present)
3045 have been changed back to 'long'. This is required for 'timezone'
3046 by POSIX, and for 'altzone' by common practice, e.g., Solaris 11.
3047 These variables were originally 'long' in the tz code, but were
3048 mistakenly changed to 'time_t' in 1987; nobody reported the
3049 incompatibility until now. The difference matters on x32, where
3050 'long' is 32 bits and 'time_t' is 64. (Thanks to Elliott Hughes.)
3052 Changes affecting the build procedure
3054 Avoid long strings in leapseconds.awk to work around a mawk bug.
3055 (Thanks to Cyril Baurand.)
3057 Changes affecting documentation and commentary
3059 New file 'NEWS' that contains release notes like this one.
3061 Paraguay's law does not specify DST transition time; 00:00 is customary.
3062 (Thanks to Waldemar Villamayor-Venialbo.)
3064 Minor capitalization fixes.
3066 Changes affecting version-control only
3068 The experimental GitHub repository now contains annotated and
3069 signed tags for recent releases, e.g., '2013e' for Release 2013e.
3070 Releases are tagged starting with 2012e; earlier releases were
3071 done differently, and tags would either not have a simple name or
3072 not exactly match what was released.
3074 'make set-timestamps' is now simpler and a bit more portable.
3077 Release 2013e - 2013-09-19 23:50:04 -0700
3079 Changes affecting near-future timestamps
3081 This year Fiji will start DST on October 27, not October 20.
3082 (Thanks to David Wheeler for the heads-up.) For now, guess that
3083 Fiji will continue to spring forward the Sunday before the fourth
3086 Changes affecting current and future time zone abbreviations
3088 Use WIB/WITA/WIT rather than WIT/CIT/EIT for alphabetic Indonesian
3089 time zone abbreviations since 1932. (Thanks to George Ziegler,
3090 Priyadi Iman Nurcahyo, Zakaria, Jason Grimes, Martin Pitt, and
3091 Benny Lin.) This affects Asia/Dili, Asia/Jakarta, Asia/Jayapura,
3092 Asia/Makassar, and Asia/Pontianak.
3094 Use ART (UT -03, standard time), rather than WARST (also -03, but
3095 daylight saving time) for San Luis, Argentina since 2009.
3097 Changes affecting Godthåb timestamps after 2037 if version mismatch
3099 Allow POSIX-like TZ strings where the transition time's hour can
3100 range from -167 through 167, instead of the POSIX-required 0
3101 through 24. E.g., TZ='FJT-12FJST,M10.3.1/146,M1.3.4/75' for the
3102 new Fiji rules. This is a more-compact way to represent
3103 far-future timestamps for America/Godthab, America/Santiago,
3104 Antarctica/Palmer, Asia/Gaza, Asia/Hebron, Asia/Jerusalem,
3105 Pacific/Easter, and Pacific/Fiji. Other zones are unaffected by
3106 this change. (Derived from a suggestion by Arthur David Olson.)
3108 Allow POSIX-like TZ strings where daylight saving time is in
3109 effect all year. E.g., TZ='WART4WARST,J1/0,J365/25' for Western
3110 Argentina Summer Time all year. This supports a more-compact way
3111 to represent the 2013d data for America/Argentina/San_Luis.
3112 Because of the change for San Luis noted above this change does not
3113 affect the current data. (Thanks to Andrew Main (Zefram) for
3114 suggestions that improved this change.)
3116 Where these two TZ changes take effect, there is a minor extension
3117 to the tz file format in that it allows new values for the
3118 embedded TZ-format string, and the tz file format version number
3119 has therefore been increased from 2 to 3 as a precaution.
3120 Version-2-based client code should continue to work as before for
3121 all timestamps before 2038. Existing version-2-based client code
3122 (tzcode, GNU/Linux, Solaris) has been tested on version-3-format
3123 files, and typically works in practice even for timestamps after
3124 2037; the only known exception is America/Godthab.
3126 Changes affecting timestamps before 1970
3128 Pacific/Johnston is now a link to Pacific/Honolulu. This corrects
3129 some errors before 1947.
3131 Some zones have been turned into links, when they differ from existing
3132 zones only in older data entries that were likely invented or that
3133 differ only in LMT or transitions from LMT. These changes affect
3134 only timestamps before 1943. The affected zones are:
3135 Africa/Juba, America/Anguilla, America/Aruba, America/Dominica,
3136 America/Grenada, America/Guadeloupe, America/Marigot,
3137 America/Montserrat, America/St_Barthelemy, America/St_Kitts,
3138 America/St_Lucia, America/St_Thomas, America/St_Vincent,
3139 America/Tortola, and Europe/Vaduz. (Thanks to Alois Treindl for
3140 confirming that the old Europe/Vaduz zone was wrong and the new
3141 link is better for WWII-era times.)
3143 Change Kingston Mean Time from -5:07:12 to -5:07:11. This affects
3144 America/Cayman, America/Jamaica and America/Grand_Turk timestamps
3147 Change the UT offset of Bern Mean Time from 0:29:44 to 0:29:46.
3148 This affects Europe/Zurich timestamps from 1853 to 1894. (Thanks
3151 Change the date of the circa-1850 Zurich transition from 1849-09-12
3152 to 1853-07-16, overriding Shanks with data from Messerli about
3153 postal and telegraph time in Switzerland.
3155 Changes affecting time zone abbreviations before 1970
3157 For Asia/Jakarta, use BMT (not JMT) for mean time from 1923 to 1932,
3158 as Jakarta was called Batavia back then.
3160 Changes affecting API
3162 The 'zic' command now outputs a dummy transition when far-future
3163 data can't be summarized using a TZ string, and uses a 402-year
3164 window rather than a 400-year window. For the current data, this
3165 affects only the Asia/Tehran file. It does not affect any of the
3166 timestamps that this file represents, so zdump outputs the same
3167 information as before. (Thanks to Andrew Main (Zefram).)
3169 The 'date' command has a new '-r' option, which lets you specify
3170 the integer time to display, a la FreeBSD.
3172 The 'tzselect' command has two new options '-c' and '-n', which lets you
3173 select a zone based on latitude and longitude.
3175 The 'zic' command's '-v' option now warns about constructs that
3176 require the new version-3 binary file format. (Thanks to Arthur
3177 David Olson for the suggestion.)
3179 Support for floating-point time_t has been removed.
3180 It was always dicey, and POSIX no longer requires it.
3181 (Thanks to Eric Blake for suggesting to the POSIX committee to
3182 remove it, and thanks to Alan Barrett, Clive D.W. Feather, Andy
3183 Heninger, Arthur David Olson, and Alois Treindl, for reporting
3184 bugs and elucidating some of the corners of the old floating-point
3187 The signatures of 'offtime', 'timeoff', and 'gtime' have been
3188 changed back to the old practice of using 'long' to represent UT
3189 offsets. This had been inadvertently and mistakenly changed to
3190 'int_fast32_t'. (Thanks to Christos Zoulas.)
3192 The code avoids undefined behavior on integer overflow in some
3193 more places, including gmtime, localtime, mktime and zdump.
3195 Changes affecting the zdump utility
3197 zdump now outputs "UT" when referring to Universal Time, not "UTC".
3198 "UTC" does not make sense for timestamps that predate the introduction
3199 of UTC, whereas "UT", a more-generic term, does. (Thanks to Steve Allen
3200 for clarifying UT vs UTC.)
3202 Data changes affecting behavior of tzselect and similar programs
3204 Country code BQ is now called the more-common name "Caribbean Netherlands"
3205 rather than the more-official "Bonaire, St Eustatius & Saba".
3207 Remove from zone.tab the names America/Montreal, America/Shiprock,
3208 and Antarctica/South_Pole, as they are equivalent to existing
3209 same-country-code zones for post-1970 timestamps. The data entries for
3210 these names are unchanged, so the names continue to work as before.
3212 Changes affecting code internals
3214 zic -c now runs way faster on 64-bit hosts when given large numbers.
3216 zic now uses vfprintf to avoid allocating and freeing some memory.
3218 tzselect now computes the list of continents from the data,
3219 rather than have it hard-coded.
3221 Minor changes pacify GCC 4.7.3 and GCC 4.8.1.
3223 Changes affecting the build procedure
3225 The 'leapseconds' file is now generated automatically from a
3226 new file 'leap-seconds.list', which is a copy of
3227 <ftp://ftp.nist.gov/pub/time/leap-seconds.list>
3228 A new source file 'leapseconds.awk' implements this.
3229 The goal is simplification of the future maintenance of 'leapseconds'.
3231 When building the 'posix' or 'right' subdirectories, if the
3232 subdirectory would be a copy of the default subdirectory, it is
3233 now made a symbolic link if that is supported. This saves about
3234 2 MB of file system space.
3236 The links America/Shiprock and Antarctica/South_Pole have been
3237 moved to the 'backward' file. This affects only nondefault builds
3238 that omit 'backward'.
3240 Changes affecting version-control only
3242 .gitignore now ignores 'date'.
3244 Changes affecting documentation and commentary
3246 Changes to the 'tzfile' man page
3248 It now mentions that the binary file format may be extended in
3249 future versions by appending data.
3251 It now refers to the 'zdump' and 'zic' man pages.
3253 Changes to the 'zic' man page
3255 It lists conditions that elicit a warning with '-v'.
3257 It says that the behavior is unspecified when duplicate names
3258 are given, or if the source of one link is the target of another.
3260 Its examples are updated to match the latest data.
3262 The definition of white space has been clarified slightly.
3263 (Thanks to Michael Deckers.)
3265 Changes to the 'Theory' file
3267 There is a new section about the accuracy of the tz database,
3268 describing the many ways that errors can creep in, and
3269 explaining why so many of the pre-1970 timestamps are wrong or
3270 misleading (thanks to Steve Allen, Lester Caine, and Garrett
3271 Wollman for discussions that contributed to this).
3273 The 'Theory' file describes LMT better (this follows a
3274 suggestion by Guy Harris).
3276 It refers to the 2013 edition of POSIX rather than the 2004 edition.
3278 It's mentioned that excluding 'backward' should not affect the
3279 other data, and it suggests at least one zone.tab name per
3280 inhabited country (thanks to Stephen Colebourne).
3282 Some longstanding restrictions on names are documented, e.g.,
3283 'America/New_York' precludes 'America/New_York/Bronx'.
3285 It gives more reasons for the 1970 cutoff.
3287 It now mentions which time_t variants are supported, such as
3288 signed integer time_t. (Thanks to Paul Goyette for reporting
3289 typos in an experimental version of this change.)
3291 (Thanks to Philip Newton for correcting typos in these changes.)
3293 Documentation and commentary is more careful to distinguish UT in
3294 general from UTC in particular. (Thanks to Steve Allen.)
3296 Add a better source for the Zurich 1894 transition.
3297 (Thanks to Pierre-Yves Berger.)
3299 Update shapefile citations in tz-link.htm. (Thanks to Guy Harris.)
3302 Release 2013d - 2013-07-05 07:38:01 -0700
3304 Changes affecting future timestamps:
3306 Morocco's midsummer transitions this year are July 7 and August 10,
3307 not July 9 and August 8. (Thanks to Andrew Paprocki.)
3309 Israel now falls back on the last Sunday of October.
3310 (Thanks to Ephraim Silverberg.)
3312 Changes affecting past timestamps:
3314 Specify Jerusalem's location more precisely; this changes the pre-1880
3317 Changing affecting metadata only:
3319 Fix typos in the entries for country codes BQ and SX.
3321 Changes affecting code:
3323 Rework the code to fix a bug with handling Australia/Macquarie on
3324 32-bit hosts (thanks to Arthur David Olson).
3326 Port to platforms like NetBSD, where time_t can be wider than long.
3328 Add support for testing time_t types other than the system's.
3329 Run 'make check_time_t_alternatives' to try this out.
3330 Currently, the tests fail for unsigned time_t;
3331 this should get fixed at some point.
3333 Changes affecting documentation and commentary:
3335 Deemphasize the significance of national borders.
3337 Update the zdump man page.
3339 Remove obsolete NOID comment (thanks to Denis Excoffier).
3341 Update several URLs and comments in the web pages.
3343 Spelling fixes (thanks to Kevin Lyda and Jonathan Leffler).
3345 Update URL for CLDR Zone->Tzid table (thanks to Yoshito Umaoka).
3348 Release 2013c - 2013-04-19 16:17:40 -0700
3350 Changes affecting current and future timestamps:
3352 Palestine observed DST starting March 29, 2013. (Thanks to
3353 Steffen Thorsen.) From 2013 on, Gaza and Hebron both observe DST,
3354 with the predicted rules being the last Thursday in March at 24:00
3355 to the first Friday on or after September 21 at 01:00.
3357 Assume that the recent change to Paraguay's DST rules is permanent,
3358 by moving the end of DST to the 4th Sunday in March every year.
3359 (Thanks to Carlos Raúl Perasso.)
3361 Changes affecting past timestamps:
3363 Fix some historical data for Palestine to agree with that of
3364 timeanddate.com, as follows:
3366 The spring 2008 change in Gaza and Hebron was on 00:00 Mar 28, not
3369 The fall 2009 change in Gaza and Hebron on Sep 4 was at 01:00, not
3372 The spring 2010 change in Hebron was 00:00 Mar 26, not 00:01 Mar 27.
3374 The spring 2011 change in Gaza was 00:01 Apr 1, not 12:01 Apr 2.
3376 The spring 2011 change in Hebron on Apr 1 was at 00:01, not 12:01.
3378 The fall 2011 change in Hebron on Sep 30 was at 00:00, not 03:00.
3380 Fix times of habitation for Macquarie to agree with the Tasmania
3381 Parks & Wildlife Service history, which indicates that permanent
3382 habitation was 1899-1919 and 1948 on.
3384 Changing affecting metadata only:
3386 Macquarie Island is politically part of Australia, not Antarctica.
3387 (Thanks to Tobias Conradi.)
3389 Sort Macquarie more-consistently with other parts of Australia.
3390 (Thanks to Tim Parenti.)
3393 Release 2013b - 2013-03-10 22:33:40 -0700
3395 Changes affecting current and future timestamps:
3397 Haiti uses US daylight-saving rules this year, and presumably future years.
3398 This changes timestamps starting today. (Thanks to Steffen Thorsen.)
3400 Paraguay will end DST on March 24 this year.
3401 (Thanks to Steffen Thorsen.) For now, assume it's just this year.
3403 Morocco does not observe DST during Ramadan;
3404 try to predict Ramadan in Morocco as best we can.
3405 (Thanks to Erik Homoet for the heads-up.)
3407 Changes affecting commentary:
3409 Update URLs in tz-link page. Add URLs for webOS, BB10, iOS.
3410 Update URL for Solaris. Mention Internet RFC 6557.
3411 Update Internet RFCs 2445->5545, 2822->5322.
3412 Switch from FTP to HTTP for Internet RFCs.
3415 Release 2013a - 2013-02-27 09:20:35 -0800
3417 Change affecting binary data format:
3419 The zone offset at the end of version-2-format zone files is now
3420 allowed to be 24:00, as per POSIX.1-2008. (Thanks to Arthur David Olson.)
3422 Changes affecting current and future timestamps:
3424 Chile's 2013 rules, and we guess rules for 2014 and later, will be
3425 the same as 2012, namely Apr Sun>=23 03:00 UTC to Sep Sun>=2 04:00 UTC.
3426 (Thanks to Steffen Thorsen and Robert Elz.)
3428 New Zones Asia/Khandyga, Asia/Ust-Nera, Europe/Busingen.
3429 (Thanks to Tobias Conradi and Arthur David Olson.)
3431 Many changes affect historical timestamps before 1940.
3432 These were deduced from: Milne J. Civil time. Geogr J. 1899
3433 Feb;13(2):173-94 <https://www.jstor.org/stable/1774359>.
3435 Changes affecting the code:
3437 Fix zic bug that mishandled Egypt's 2010 changes (this also affected
3438 the data). (Thanks to Arthur David Olson.)
3440 Fix localtime bug when time_t is unsigned and data files were generated
3441 by a signed time_t system. (Thanks to Doug Bailey for reporting and
3442 to Arthur David Olson for fixing.)
3444 Allow the email address for bug reports to be set by the packager.
3445 The default is tz@iana.org, as before. (Thanks to Joseph S. Myers.)
3447 Update HTML checking to be compatible with Ubuntu 12.10.
3449 Check that files are a safe subset of ASCII. At some point we may
3450 relax this requirement to a safe subset of UTF-8. Without the
3451 check, some non-UTF-8 encodings were leaking into the distribution.
3455 Restore a comment about copyright notices that was inadvertently deleted.
3456 (Thanks to Arthur David Olson.)
3458 Improve the commentary about which districts observe what times
3459 in Russia. (Thanks to Oscar van Vlijmen and Arthur David Olson.)
3461 Add web page links to tz.js.
3463 Add "Run by the Monkeys" to tz-art. (Thanks to Arthur David Olson.)
3466 Release 2012j - 2012-11-12 18:34:49 -0800
3468 Libya moved to CET this weekend, but with DST planned next year.
3469 (Thanks to Even Scharning, Steffen Thorsen, and Tim Parenti.)
3471 Signatures now have the extension .asc, not .sign, as that's more
3472 standard. (Thanks to Phil Pennock.)
3474 The output of 'zdump --version', and of 'zic --version', now
3475 uses a format that is more typical for --version.
3476 (Thanks to Joseph S. Myers.)
3478 The output of 'tzselect --help', 'zdump --help', and 'zic --help'
3479 now uses tz@iana.org rather than the old elsie address.
3481 zic -v now complains about abbreviations that are less than 3
3482 or more than 6 characters, as per Posix. Formerly, it checked
3483 for abbreviations that were more than 3.
3485 'make public' no longer puts its temporary directory under /tmp,
3486 and uses the just-built zic rather than the system zic.
3488 Various fixes to documentation and commentary.
3491 Release 2012i - 2012-11-03 12:57:09 -0700
3493 Cuba switches from DST tomorrow at 01:00. (Thanks to Steffen Thorsen.)
3495 Linker flags can now be specified via LDFLAGS.
3496 AWK now defaults to 'awk', not 'nawk'.
3497 The shell in tzselect now defaults to /bin/bash, but this can
3498 be overridden by specifying KSHELL.
3499 The main web page now mentions the unofficial GitHub repository.
3500 (Thanks to Mike Frysinger.)
3502 Tarball signatures can now be built by running 'make signatures'.
3503 There are also new makefile rules 'tarballs', 'check_public', and
3504 separate makefile rules for each tarball and signature file.
3505 A few makefile rules are now more portable to strict POSIX.
3507 The main web page now lists the canonical IANA URL.
3510 Release 2012h - 2012-10-26 22:49:10 -0700
3512 Bahia no longer has DST. (Thanks to Kelley Cook.)
3514 Tocantins has DST. (Thanks to Rodrigo Severo.)
3516 Israel has new DST rules next year. (Thanks to Ephraim Silverberg.)
3518 Jordan stays on DST this winter. (Thanks to Steffen Thorsen.)
3522 More C modernization, except that at Arthur David Olson's suggestion
3523 the instances of 'register' were kept.
3526 Release 2012g - 2012-10-17 20:59:45 -0700
3528 Samoa fall 2012 and later. (Thanks to Nicholas Pereira and Robert Elz.)
3530 Palestine fall 2012. (Thanks to Steffen Thorsen.)
3534 To attack the version-number problem, this release ships the file
3535 'Makefile' (which contains the release number) in both the tzcode and
3536 the tzdata tarballs. The two Makefiles are identical, and should be
3537 identical in any matching pair of tarballs, so it shouldn't matter
3538 which order you extract the tarballs. Perhaps we can come up with a
3539 better version-number scheme at some point; this scheme does have the
3540 virtue of not adding more files.
3543 Release 2012f - 2012-09-12 23:17:03 -0700
3545 * australasia (Pacific/Fiji): Fiji DST is October 21 through January
3546 20 this year. (Thanks to Steffen Thorsen.)
3549 Release 2012e - 2012-08-02 20:44:55 -0700
3551 * australasia (Pacific/Fakaofo): Tokelau is UT +13, not +14.
3552 (Thanks to Steffen Thorsen.)
3554 * Use a single version number for both code and data.
3556 * .gitignore: New file.
3558 * Remove trailing white space.
3561 Release code2012c-data2012d - 2012-07-19 16:35:33 -0700
3563 Changes for Morocco's timestamps, which take effect in a couple of
3564 hours, along with infrastructure changes to accommodate how the tz
3565 code and data are released on IANA.
3568 Release data2012c - 2012-03-27 12:17:25 -0400
3571 Summer time changes for Morocco (to start late April 2012)
3574 Changes for 2012 for Gaza & the West Bank (Hebron) and Syria
3577 Haiti following US/Canada rules for 2012 (and we're assuming,
3578 for now anyway, for the future).
3581 Release 2012b - 2012-03-02 12:29:15 +0700
3583 There is just one change to tzcode2012b (compared with 2012a):
3584 the Makefile that was accidentally included with 2012a has been
3585 replaced with the version that should have been there, which is
3586 identical with the previous version (from tzcode2011i).
3588 There are just two changes in tzdata2012b compared with 2012a.
3590 Most significantly, summer time in Cuba has been delayed 3 weeks
3591 (now starts April 1 rather than March 11). Since Mar 11 (the old start
3592 date, as listed in 2012a) is just a little over a week away, this
3595 Less importantly, an excess tab in one of the changes in zone.tab
3596 in 2012a has been removed.
3599 Release 2012a - 2012-03-01 18:28:10 +0700
3601 The changes in tzcode2012a (compared to the previous version, 2011i)
3602 are entirely to the README and tz-art.htm and tz-link.htm files, if
3603 none of those concern you, you can ignore the code update. The changes
3604 reflect the changed addresses for the mailing list and the code and
3605 data distribution points & methods (and a link to DateTime::TimeZone::Tzfile
3606 has been added to tz-link.htm).
3608 In tzdata2012a (compared to the previous release, which was 2011n)
3609 the major changes are:
3610 Chile 2011/2012 and 2012/2013 summer time date adjustments.
3611 Falkland Islands onto permanent summer time (we're assuming for the
3612 foreseeable future, though 2012 is all we're fairly certain of.)
3613 Armenia has abolished Summer Time.
3614 Tokelau jumped the International Date Line back last December
3615 (just the same as their near neighbour, Samoa).
3616 America/Creston is a new zone for a small area of British Columbia
3617 There will be a leapsecond 2012-06-30 23:59:60 UTC.
3619 Other minor changes are:
3620 Corrections to 1918 Canadian summer time end dates.
3621 Updated URL for UK time zone history (in comments)
3622 A few typos in Le Corre's list of free French place names (comments)
3625 Release data2011n - 2011-10-30 14:57:54 +0700
3627 There are three changes of note - most urgently, Cuba (America/Havana)
3628 has extended summer time by two weeks, now to end on Nov 13, rather than
3629 the (already past) Oct 30. Second, the Pridnestrovian Moldavian Republic
3630 (Europe/Tiraspol) decided not to split from the rest of Moldova after
3631 all, and consequently that zone has been removed (again) and reinstated
3632 in the "backward" file as a link to Europe/Chisinau. And third, the
3633 end date for Fiji's summer time this summer was moved forward from the
3634 earlier planned Feb 26, to Jan 22.
3636 Apart from that, Moldova (MD) returns to a single entry in zone.tab
3637 (and the incorrect syntax that was in the 2011m version of that file
3638 is so fixed - it would have been fixed in a different way had this
3639 change not happened - that's the "missing" sccs version id).
3642 Release data2011m - 2011-10-24 21:42:16 +0700
3644 In particular, the typos in comments in the data (2011-11-17 should have
3645 been 2011-10-17 as Alan Barrett noted, and spelling of Tiraspol that
3646 Tim Parenti noted) have been fixed, and the change for Ukraine has been
3647 made in all 4 Ukrainian zones, rather than just Kiev (again, thanks to
3648 Tim Parenti, and also Denys Gavrysh)
3650 In addition, I added Europe/Tiraspol to zone.tab.
3652 This time, all the files have new version numbers... (including the files
3653 otherwise unchanged in 2011m that were changed in 2011l but didn't get new
3654 version numbers there...)
3657 Release data2011l - 2011-10-10 11:15:43 +0700
3659 There are just 2 changes that cause different generated tzdata files from
3660 zic, to Asia/Hebron and Pacific/Fiji - the possible change for Bahia, Brazil
3661 is included, but commented out. Compared with the diff I sent out last week,
3662 this version also includes attributions for the sources for the changes
3663 (in much the same format as ado used, but the html tags have not been
3664 checked, verified, or used in any way at all, so if there are errors there,
3665 please let me know.)
3668 Release data2011k - 2011-09-20 17:54:03 -0400
3673 Release data2011j - 2011-09-12 09:22:49 -0400
3675 (contemporary changes for Samoa; past changes for Kenya, Uganda, and
3676 Tanzania); there are also two spelling corrections to comments in
3677 the australasia file (with thanks to Christos Zoulas).
3680 Release 2011i - 2011-08-29 05:56:32 -0400
3685 Release data2011h - 2011-06-15 18:41:48 -0400
3687 Russia and Curaçao changes
3690 Release 2011g - 2011-04-25 09:07:22 -0400
3692 update the rules for Egypt to reflect its abandonment of DST this year
3695 Release 2011f - 2011-04-06 17:14:53 -0400
3700 Release 2011e - 2011-03-31 16:04:38 -0400
3702 Morocco, Chile, and tz-link changes
3705 Release 2011d - 2011-03-14 09:18:01 -0400
3707 changes that impact present-day timestamps in Cuba, Samoa, and Turkey
3710 Release 2011c - 2011-03-07 09:30:09 -0500
3712 These do affect current timestamps in Chile and Annette Island, Canada.
3715 Release 2011b - 2011-02-07 08:44:50 -0500
3720 Release 2011a - 2011-01-24 10:30:16 -0500
3725 Release data2010o - 2010-11-01 09:18:23 -0400
3727 change to the end of DST in Fiji in 2011
3730 Release 2010n - 2010-10-25 08:19:17 -0400
3735 Release 2010m - 2010-09-27 09:24:48 -0400
3737 Hong Kong, Vostok, and zic.c changes
3740 Release 2010l - 2010-08-16 06:57:25 -0400
3745 Release 2010k - 2010-07-26 10:42:27 -0400
3750 Release 2010j - 2010-05-10 09:07:48 -0400
3752 changes for Bahía de Banderas and for version naming
3755 Release data2010i - 2010-04-16 18:50:45 -0400
3757 the end of DST in Morocco on 2010-08-08
3760 Release data2010h - 2010-04-05 09:58:56 -0400
3765 Release data2010g - 2010-03-24 11:14:53 -0400
3770 Release 2010f - 2010-03-22 09:45:46 -0400
3775 Release data2010e - 2010-03-08 14:24:27 -0500
3777 corrects the Dhaka bug found by Danvin Ruangchan
3780 Release data2010d - 2010-03-06 07:26:01 -0500
3785 Release 2010c - 2010-03-01 09:20:58 -0500
3787 changes including KRE's suggestion for earlier initialization of
3788 "goahead" and "goback" structure elements
3791 Release code2010a - 2010-02-16 10:40:04 -0500
3796 Release data2010b - 2010-01-20 12:37:01 -0500
3801 Release data2010a - 2010-01-18 08:30:04 -0500
3806 Release data2009u - 2009-12-26 08:32:28 -0500
3808 changes to DST in Bangladesh
3811 Release 2009t - 2009-12-21 13:24:27 -0500
3816 Release data2009s - 2009-11-14 10:26:32 -0500
3818 (cosmetic) Antarctica change and the DST-in-Fiji-in-2009-and-2010 change
3821 Release 2009r - 2009-11-09 10:10:31 -0500
3823 "antarctica" and "tz-link.htm" changes
3826 Release 2009q - 2009-11-02 09:12:40 -0500
3828 with two corrections as reported by Eric Muller and Philip Newton
3831 Release data2009p - 2009-10-23 15:05:27 -0400
3833 Argentina (including San Luis) changes (with the correction from
3837 Release data2009o - 2009-10-14 16:49:38 -0400
3839 Samoa (commentary only), Pakistan, and Bangladesh changes
3842 Release data2009n - 2009-09-22 15:13:38 -0400
3844 added commentary for Argentina and a change to the end of DST in
3848 Release data2009m - 2009-09-03 10:23:43 -0400
3850 Samoa and Palestine changes
3853 Release data2009l - 2009-08-14 09:13:07 -0400
3855 Samoa (comments only) and Egypt
3858 Release 2009k - 2009-07-20 09:46:08 -0400
3863 Release data2009j - 2009-06-15 06:43:59 -0400
3865 Bangladesh change (with a short turnaround since the DST change is
3869 Release 2009i - 2009-06-08 09:21:22 -0400
3871 updating for DST in Bangladesh this year
3874 Release 2009h - 2009-05-26 09:19:14 -0400
3879 Release data2009g - 2009-04-20 16:34:07 -0400
3884 Release data2009f - 2009-04-10 11:00:52 -0400
3886 correct DST in Pakistan
3889 Release 2009e - 2009-04-06 09:08:11 -0400
3894 Release 2009d - 2009-03-23 09:38:12 -0400
3896 Morocco, Tunisia, Argentina, and American Astronomical Society changes
3899 Release data2009c - 2009-03-16 09:47:51 -0400
3901 change to the start of Cuban DST
3904 Release 2009b - 2009-02-09 11:15:22 -0500
3909 Release 2009a - 2009-01-21 10:09:39 -0500
3914 Release data2008i - 2008-10-21 12:10:25 -0400
3916 southamerica and zone.tab files, with Argentina DST rule changes and
3917 United States zone reordering and recommenting
3920 Release 2008h - 2008-10-13 07:33:56 -0400
3925 Release 2008g - 2008-10-06 09:03:18 -0400
3927 Fix a broken HTML anchor and update Brazil's DST transitions;
3928 there's also a slight reordering of information in tz-art.htm.
3931 Release data2008f - 2008-09-09 22:33:26 -0400
3936 Release 2008e - 2008-07-28 14:11:17 -0400
3938 changes by Arthur David Olson and Jesper Nørgaard Welen
3941 Release data2008d - 2008-07-07 09:51:38 -0400
3943 changes by Arthur David Olson, Paul Eggert, and Rodrigo Severo
3946 Release data2008c - 2008-05-19 17:48:03 -0400
3948 Pakistan, Morocco, and Mongolia
3951 Release data2008b - 2008-03-24 08:30:59 -0400
3953 including renaming Asia/Calcutta to Asia/Kolkata, with a backward
3957 Release 2008a - 2008-03-08 05:42:16 -0500
3962 Release 2007k - 2007-12-31 10:25:22 -0500
3964 most importantly, changes to the "southamerica" file based on
3965 Argentina's readoption of daylight saving time
3968 Release 2007j - 2007-12-03 09:51:01 -0500
3970 1. eliminate the "P" (parameter) macro;
3972 2. the "noncontroversial" changes circulated on the time zone
3973 mailing list (less the changes to "logwtmp.c");
3975 3. eliminate "too many transition" errors when "min" is used in time
3978 4. changes by Paul Eggert (including updated information for Venezuela).
3981 Release data2007i - 2007-10-30 10:28:11 -0400
3983 changes for Cuba and Syria
3986 Release 2007h - 2007-10-01 10:05:51 -0400
3988 changes by Paul Eggert, as well as an updated link to the ICU
3989 project in tz-link.htm
3992 Release 2007g - 2007-08-20 10:47:59 -0400
3994 changes by Paul Eggert
3996 The "leapseconds" file has been updated to incorporate the most
3997 recent International Earth Rotation and Reference Systems Service
4000 There's an addition to tz-art.htm regarding the television show "Medium".
4003 Release 2007f - 2007-05-07 10:46:46 -0400
4005 changes by Paul Eggert (including Haiti, Turks and Caicos, and New
4008 changes to zic.c to allow hour values greater than 24 (along with
4009 Paul's improved time value overflow checking)
4012 Release 2007e - 2007-04-02 10:11:52 -0400
4014 Syria and Honduras changes by Paul Eggert
4016 zic.c variable renaming changes by Arthur David Olson
4019 Release 2007d - 2007-03-20 08:48:30 -0400
4021 changes by Paul Eggert
4023 the elimination of white space at the ends of lines
4026 Release 2007c - 2007-02-26 09:09:37 -0500
4028 changes by Paul Eggert
4031 Release 2007b - 2007-02-12 09:34:20 -0500
4033 Paul Eggert's proposed change to the quotation handling logic in zic.c.
4035 changes to the commentary in "leapseconds" reflecting the IERS
4036 announcement that there is to be no positive leap second at the end
4040 Release 2007a - 2007-01-08 12:28:29 -0500
4042 changes by Paul Eggert
4044 Derick Rethan's Asmara change
4046 Oscar van Vlijmen's Easter Island local mean time change
4048 symbolic link changes
4051 Release 2006p - 2006-11-27 08:54:27 -0500
4053 changes by Paul Eggert
4056 Release 2006o - 2006-11-06 09:18:07 -0500
4058 changes by Paul Eggert
4061 Release 2006n - 2006-10-10 11:32:06 -0400
4063 changes by Paul Eggert
4066 Release 2006m - 2006-10-02 15:32:35 -0400
4068 changes for Uruguay, Palestine, and Egypt by Paul Eggert
4070 (minimalist) changes to zic.8 to clarify "until" information
4073 Release data2006l - 2006-09-18 12:58:11 -0400
4075 Paul's best-effort work on this coming weekend's Egypt time change
4078 Release 2006k - 2006-08-28 12:19:09 -0400
4080 changes by Paul Eggert
4083 Release 2006j - 2006-08-21 09:56:32 -0400
4085 changes by Paul Eggert
4088 Release code2006i - 2006-08-07 12:30:55 -0400
4092 Ken Pizzini's conversion script
4095 Release code2006h - 2006-07-24 09:19:37 -0400
4097 adds public domain notices to four files
4099 includes a fix for transition times being off by a second
4101 adds a new recording to the "arts" file (information courtesy Colin Bowern)
4104 Release 2006g - 2006-05-08 17:18:09 -0400
4106 northamerica changes by Paul Eggert
4109 Release 2006f - 2006-05-01 11:46:00 -0400
4111 a missing version number problem is fixed (with thanks to Bradley
4112 White for catching the problem)
4115 Release 2006d - 2006-04-17 14:33:43 -0400
4117 changes by Paul Eggert
4119 added new items to tz-arts.htm that were found by Paul
4122 Release 2006c - 2006-04-03 10:09:32 -0400
4124 two sets of data changes by Paul Eggert
4126 a fencepost error fix in zic.c
4128 changes to zic.c and the "europe" file to minimize differences
4129 between output produced by the old 32-bit zic and the new 64-bit
4133 Release 2006b - 2006-02-20 10:08:18 -0500
4134 [tz32code2006b + tz64code2006b + tzdata2006b]
4138 All SCCS IDs were bumped to "8.1" for this release.
4141 Release 2006a - 2006-01-30 08:59:31 -0500
4143 changes by Paul Eggert (in particular, Indiana time zone moves)
4145 an addition to the zic manual page to describe how special-case
4146 transitions are handled
4149 Release 2005r - 2005-12-27 09:27:13 -0500
4151 Canadian changes by Paul Eggert
4153 They also add "<pre>" directives to time zone data files and reflect
4154 changes to warning message logic in "zdump.c" (but with calls to
4155 "gettext" kept unbundled at the suggestion of Ken Pizzini).
4158 Release 2005q - 2005-12-13 09:17:09 -0500
4160 Nothing earth-shaking here:
4161 1. Electronic mail addresses have been removed.
4162 2. Casts of the return value of exit have been removed.
4163 3. Casts of the argument of is.* macros have been added.
4164 4. Indentation in one section of zic.c has been fixed.
4165 5. References to dead URLs in the data files have been dealt with.
4168 Release 2005p - 2005-12-05 10:30:53 -0500
4170 "systemv", "tz-link.htm", and "zdump.c" changes
4171 (less the casts of arguments to the is* macros)
4174 Release 2005o - 2005-11-28 10:55:26 -0500
4176 Georgia, Cuba, Nicaragua, and Jordan changes by Paul Eggert
4178 zdump.c lint fixes by Arthur David Olson
4181 Release 2005n - 2005-10-03 09:44:09 -0400
4183 changes by Paul Eggert (both the Uruguay changes and the Kyrgyzstan
4187 Release 2005m - 2005-08-29 12:15:40 -0400
4189 changes by Paul Eggert (with a small tweak to the tz-art change)
4191 a declaration of an unused variable has been removed from zdump.c
4194 Release 2005l - 2005-08-22 12:06:39 -0400
4196 changes by Paul Eggert
4198 overflow/underflow checks by Arthur David Olson, minus changes to
4199 the "Theory" file about the pending addition of 64-bit data (I grow
4200 less confident of the changes being accepted with each passing day,
4201 and the changes no longer increase the data files nine-fold--there's
4202 less than a doubling in size by my local Sun's reckoning)
4205 Release 2005k - 2005-07-14 14:14:24 -0400
4207 The "leapseconds" file has been edited to reflect the recently
4208 announced leap second at the end of 2005.
4210 I've also deleted electronic mail addresses from the files as an
4214 Release 2005j - 2005-06-13 14:34:13 -0400
4216 These reflect changes to limit the length of time zone abbreviations
4217 and the characters used in those abbreviations.
4219 There are also changes to handle POSIX-style "quoted" timezone
4220 environment variables.
4222 The changes were circulated on the time zone mailing list; the only
4223 change since then was the removal of a couple of minimum-length of
4224 abbreviation checks.
4227 Release data2005i - 2005-04-21 15:04:16 -0400
4229 changes (most importantly to Nicaragua and Haiti) by Paul Eggert
4232 Release 2005h - 2005-04-04 11:24:47 -0400
4234 changes by Paul Eggert
4236 minor changes to Makefile and zdump.c to produce more useful output
4237 when doing a "make typecheck"
4240 Release 2005g - 2005-03-14 10:11:21 -0500
4242 changes by Paul Eggert (a change to current DST rules in Uruguay and
4243 an update to a link to time zone software)
4246 Release 2005f - 2005-03-01 08:45:32 -0500
4248 data and documentation changes by Paul Eggert
4251 Release 2005e - 2005-02-10 15:59:44 -0500
4256 Release code2005d - 2005-01-31 09:21:47 -0500
4258 make zic complain about links to links if the -v flag is used
4260 have "make public" do more code checking
4262 add an include to "localtime.c" for the benefit of gcc systems
4265 Release 2005c - 2005-01-17 18:36:29 -0500
4267 get better results when mktime runs on a system where time_t is double
4269 changes to the data files (most importantly to Paraguay)
4272 Release 2005b - 2005-01-10 09:19:54 -0500
4274 Get localtime and gmtime working on systems with exotic time_t types.
4276 Update the leap second commentary in the "leapseconds" file.
4279 Release 2005a - 2005-01-01 13:13:44 -0500
4284 Release code2004i - 2004-12-14 13:42:58 -0500
4286 Deal with systems where time_t is unsigned.
4289 Release code2004h - 2004-12-07 11:40:18 -0500
4291 64-bit-time_t changes
4294 Release 2004g - 2004-11-02 09:06:01 -0500
4296 update to Cuba (taking effect this weekend)
4298 other changes by Paul Eggert
4300 correction of the spelling of Oslo
4302 changed versions of difftime.c and private.h
4305 Release code2004f - 2004-10-21 10:25:22 -0400
4307 Cope with wide-ranging tm_year values.
4310 Release 2004e - 2004-10-11 14:47:21 -0400
4312 Brazil/Argentina/Israel changes by Paul Eggert
4314 changes to tz-link.htm by Paul
4316 one small fix to Makefile
4319 Release 2004d - 2004-09-22 08:27:29 -0400
4321 Avoid overflow problems when TM_YEAR_BASE is added to an integer.
4324 Release 2004c - 2004-08-11 12:06:26 -0400
4326 asctime-related changes
4328 (variants of) some of the documentation changes suggested by Paul Eggert
4331 Release 2004b - 2004-07-19 14:33:35 -0400
4333 data changes by Paul Eggert - most importantly, updates for Argentina
4336 Release 2004a - 2004-05-27 12:00:47 -0400
4338 changes by Paul Eggert
4340 Handle DST transitions that occur at the end of a month in some
4341 years but at the start of the following month in other years.
4343 Add a copy of the correspondence that's the basis for claims about
4344 DST in the Navajo Nation.
4347 Release 2003e - 2003-12-15 09:36:47 -0500
4349 changes by Arthur David Olson (primarily code changes)
4351 changes by Paul Eggert (primarily data changes)
4353 minor changes to "Makefile" and "northamerica" (in the latter case,
4354 optimization of the "Toronto" rules)
4357 Release 2003d - 2003-10-06 09:34:44 -0400
4359 changes by Paul Eggert
4362 Release 2003c - 2003-09-16 10:47:05 -0400
4364 Fix bad returns in zic.c's inleap function.
4365 Thanks to Bradley White for catching the problem!
4368 Release 2003b - 2003-09-16 07:13:44 -0400
4370 Add a "--version" option (and documentation) to the zic and zdump commands.
4372 changes to overflow/underflow checking in zic
4374 a localtime typo fix.
4376 Update the leapseconds and tz-art.htm files.
4379 Release 2003a - 2003-03-24 09:30:54 -0500
4381 changes by Paul Eggert
4383 a few additions and modifications to the tz-art.htm file
4386 Release 2002d - 2002-10-15 13:12:42 -0400
4388 changes by Paul Eggert, less the "Britain (UK)" change in iso3166.tab
4390 There's also a new time zone quote in "tz-art.htm".
4393 Release 2002c - 2002-04-04 11:55:20 -0500
4395 changes by Paul Eggert
4397 Change zic.c to avoid creating symlinks to files that don't exist.
4400 Release 2002b - 2002-01-28 12:56:03 -0500
4402 [These change notes are for Release 2002a, which was corrupted.
4403 2002b was a corrected version of 2002a.]
4405 changes by Paul Eggert
4407 Update the "leapseconds" file to note that there'll be no leap
4408 second at the end of June, 2002.
4410 Change "zic.c" to deal with a problem in handling the "Asia/Bishkek" zone.
4412 Change to "difftime.c" to avoid sizeof problems.
4415 Release 2001d - 2001-10-09 13:31:32 -0400
4417 changes by Paul Eggert
4420 Release 2001c - 2001-06-05 13:59:55 -0400
4422 changes by Paul Eggert and Andrew Brown
4425 Release 2001b - 2001-04-05 16:44:38 -0400
4427 changes by Paul Eggert (modulo jnorgard's typo fix)
4429 tz-art.htm has been HTMLified.
4432 Release 2001a - 2001-03-13 12:57:44 -0500
4434 changes by Paul Eggert
4436 An addition to the "leapseconds" file: comments with the text of the
4437 latest IERS leap second notice.
4439 Trailing white space has been removed from data file lines, and
4440 repeated spaces in "Rule Jordan" lines in the "asia" file have been
4444 Release 2000h - 2000-12-14 15:33:38 -0500
4446 changes by Paul Eggert
4448 one typo fix in the "art" file
4450 With providence, this is the last update of the millennium.
4453 Release 2000g - 2000-10-10 11:35:22 -0400
4455 changes by Paul Eggert
4457 correction of John Mackin's name submitted by Robert Elz
4459 Garry Shandling's Daylight Saving Time joke (!?!) from the recent
4460 Emmy Awards broadcast.
4463 Release 2000f - 2000-08-10 09:31:58 -0400
4465 changes by Paul Eggert
4467 Added information in "tz-art.htm" on a Seinfeld reference to DST.
4469 Error checking and messages in the "yearistype" script have been
4473 Release 2000e - 2000-07-31 09:27:54 -0400
4475 data changes by Paul Eggert
4477 a change to the default value of the defined constant HAVE_STRERROR
4479 the addition of a Dave Barry quote on DST to the tz-arts file
4482 Release 2000d - 2000-04-20 15:43:04 -0400
4484 changes to the documentation and code of strftime for C99 conformance
4486 a bug fix for date.c
4488 These are based on (though modified from) changes by Paul Eggert.
4491 Release 2000c - 2000-03-04 10:31:43 -0500
4493 changes by Paul Eggert
4496 Release 2000b - 2000-02-21 12:16:29 -0500
4498 changes by Paul Eggert and Joseph Myers
4500 modest tweaks to the tz-art.htm and tz-link.htm files
4503 Release 2000a - 2000-01-18 09:21:26 -0500
4505 changes by Paul Eggert
4507 The two hypertext documents have also been renamed.
4510 Release code1999i-data1999j - 1999-11-15 18:43:22 -0500
4512 Paul Eggert's changes
4514 additions to the "zic" manual page and the "Arts.htm" file
4517 Release code1999h-data1999i - 1999-11-08 14:55:21 -0500
4522 Release data1999h - 1999-10-07 03:50:29 -0400
4524 changes by Paul Eggert to "europe" (most importantly, fixing
4525 Lithuania and Estonia)
4528 Release 1999g - 1999-09-28 11:06:18 -0400
4530 data changes by Paul Eggert (most importantly, the change for
4531 Lebanon that buys correctness for this coming Sunday)
4533 The "code" file contains changes to "Makefile" and "checktab.awk" to
4534 allow better checking of time zone files before they are published.
4537 Release 1999f - 1999-09-23 09:48:14 -0400
4539 changes by Arthur David Olson and Paul Eggert
4542 Release 1999e - 1999-08-17 15:20:54 -0400
4544 changes circulated by Paul Eggert, although the change to handling
4545 of DST-specifying timezone names has been commented out for now
4546 (search for "XXX" in "localtime.c" for details). These files also
4547 do not make any changes to the start of DST in Brazil.
4549 In addition to Paul's changes, there are updates to "Arts.htm" and
4553 Release 1999d - 1999-03-30 11:31:07 -0500
4555 changes by Paul Eggert
4557 The Makefile's "make public" rule has also been changed to do a test
4558 compile of each individual time zone data file (which should help
4559 avoid problems such as the one we had with Nicosia).
4562 Release 1999c - 1999-03-25 09:47:47 -0500
4564 changes by Paul Eggert, most importantly the change for Chile.
4567 Release 1999b - 1999-02-01 17:51:44 -0500
4569 changes by Paul Eggert
4571 code changes (suggested by Mani Varadarajan, mani at be.com) for
4572 correct handling of symbolic links when building using a relative directory
4574 code changes to generate correct messages for failed links
4576 updates to the URLs in Arts.htm
4579 Release 1999a - 1999-01-19 16:20:29 -0500
4581 error message internationalizations and corrections in zic.c and
4582 zdump.c (as suggested by Vladimir Michl, vladimir.michl at upol.cz,
4586 Release code1998h-data1998i - 1998-10-01 09:56:10 -0400
4588 changes for Brazil, Chile, and Germany
4590 support for use of "24:00" in the input files for the time zone compiler
4593 Release code1998g-data1998h - 1998-09-24 10:50:28 -0400
4595 changes by Paul Eggert
4597 correction to a define in the "private.h" file
4600 Release data1998g - 1998-08-11 03:28:35 -0000
4601 [tzdata1998g.tar.gz is missing!]
4603 Lithuanian change provided by mgedmin at pub.osf.it
4605 Move creation of the GMT link with Etc/GMT to "etcetera" (from
4606 "backward") to ensure that the GMT file is created even where folks
4607 don't want the "backward" links (as suggested by Paul Eggert).
4610 Release data1998f - 1998-07-20 13:50:00 -0000
4611 [tzdata1998f.tar.gz is missing!]
4613 Update the "leapseconds" file to include the newly-announced
4614 insertion at the end of 1998.
4617 Release code1998f - 1998-06-01 10:18:31 -0400
4619 addition to localtime.c by Guy Harris
4622 Release 1998e - 1998-05-28 09:56:26 -0400
4624 The Makefile is changed to produce zoneinfo-posix rather than
4625 zoneinfo/posix, and to produce zoneinfo-leaps rather than
4628 data changes by Paul Eggert
4630 changes from Guy Harris to provide asctime_r and ctime_r
4632 A usno1998 file (substantially identical to usno1997) has been added.
4635 Release 1998d - 1998-05-14 11:58:34 -0400
4637 changes to comments (in particular, elimination of references to CIA maps).
4638 "Arts.htm", "WWW.htm", "asia", and "australasia" are the only places
4639 where changes occur.
4642 Release 1998c - 1998-02-28 12:32:26 -0500
4644 changes by Paul Eggert (save the "French correction," on which I'll
4645 wait for the dust to settle)
4649 changes and additions to Arts.htm
4652 Release 1998b - 1998-01-17 14:31:51 -0500
4654 URL cleanups and additions
4657 Release 1998a - 1998-01-13 12:37:35 -0500
4659 changes by Paul Eggert
4662 Release code1997i-data1997k - 1997-12-29 09:53:41 -0500
4664 changes by Paul Eggert, with minor modifications from Arthur David
4665 Olson to make the files more browser friendly
4668 Release code1997h-data1997j - 1997-12-18 17:47:35 -0500
4670 minor changes to put "TZif" at the start of each timezone information file
4672 a rule has also been added to the Makefile so you can
4674 to just recompile the zone information files (rather than doing a
4675 full "make install" with its other effects).
4678 Release data1997i - 1997-10-07 08:45:38 -0400
4680 changes to Africa by Paul Eggert
4683 Release code1997g-data1997h - 1997-09-04 16:56:54 -0400
4685 corrections for Uruguay (and other locations)
4687 Arthur David Olson's simple-minded fix allowing mktime to both
4688 correctly handle leap seconds and correctly handle tm_sec values
4689 upon which arithmetic has been performed.
4692 Release code1997f-data1997g - 1997-07-19 13:15:02 -0400
4694 Paul Eggert's updates
4696 a small change to a function prototype;
4698 "Music" has been renamed "Arts.htm", HTMLified, and augmented to
4699 include information on Around the World in Eighty Days.
4702 Release code1997e-data1997f - 1997-05-03 18:52:34 -0400
4704 fixes to zic's error handling
4706 changes inspired by the item circulated on Slovenia
4708 The description of Web resources has been HTMLified for browsing
4711 A new piece of tz-related music has been added to the "Music" file.
4714 Release code1997d-data1997e - 1997-03-29 12:48:52 -0500
4716 Paul Eggert's latest suggestions
4719 Release code1997c-data1997d - 1997-03-07 20:37:54 -0500
4721 changes to "zic.c" to correct performance of the "-s" option
4723 a new file "usno1997"
4726 Release data1997c - 1997-03-04 09:58:18 -0500
4731 Release 1997b - 1997-02-27 18:34:19 -0500
4733 The data file incorporates the 1997 leap second.
4735 The code file incorporates Arthur David Olson's take on the
4736 zic/multiprocessor/directory-creation situation.
4739 Release 1997a - 1997-01-21 09:11:10 -0500
4741 Paul Eggert's Antarctica (and other changes)
4743 Arthur David Olson finessed the "getopt" issue by checking against
4744 both -1 and EOF (regardless of POSIX, SunOS 4.1.1's manual says -1
4745 is returned while SunOS 5.5's manual says EOF is returned).
4748 Release code1996o-data1996n - 1996-12-27 21:42:05 -0500
4750 Paul Eggert's latest changes
4753 Release code1996n - 1996-12-16 09:42:02 -0500
4755 link snapping fix from Bruce Evans (via Garrett Wollman)
4758 Release data1996m - 1996-11-24 02:37:34 -0000
4759 [tzdata1996m.tar.gz is missing!]
4761 Paul Eggert's batch of changes
4764 Release code1996m-data1996l - 1996-11-05 14:00:12 -0500
4766 No functional changes here; the files have simply been changed to
4767 make more use of ISO style dates in comments. The names of the above
4768 files now include the year in full.
4771 Release code96l - 1996-09-08 17:12:20 -0400
4773 tzcode96k was missing a couple of pieces.
4776 Release 96k - 1996-09-08 16:06:22 -0400
4778 the latest round of changes from Paul Eggert
4780 the recent Year 2000 material
4783 Release code96j - 1996-07-30 13:18:53 -0400
4785 Set sp->typecnt as suggested by Timothy Patrick Murphy.
4788 Release code96i - 1996-07-27 20:11:35 -0400
4790 Paul's suggested patch for strftime %V week numbers
4793 Release data96i - 1996-07-01 18:13:04 -0400
4795 "northamerica" and "europe" changes by Paul Eggert
4798 Release code96h - 1996-06-05 08:02:21 -0400
4800 fix for handling transitions specified in Universal Time
4802 Some "public domain" notices have also been added.
4805 Release code96g - 1996-05-16 14:00:26 -0400
4807 fix for the simultaneous-DST-and-zone-change challenge
4810 Release data96h - 1996-05-09 17:40:51 -0400
4812 changes by Paul Eggert
4815 Release code96f-data96g - 1996-05-03 03:09:59 -0000
4816 [tzcode96f.tar.gz + tzdata96g.tar.gz are both missing!]
4818 The changes get us some of the way to fixing the problems noted in Paul
4819 Eggert's letter yesterday (in addition to a few others). The approach
4820 has been to make zic a bit smarter about figuring out what time zone
4821 abbreviations apply just after the time specified in the "UNTIL" part
4822 of a zone line. Putting the smarts in zic means avoiding having
4823 transition times show up in both "Zone" lines and "Rule" lines, which
4824 in turn avoids multiple transition time entries in time zone files.
4825 (This also makes the zic input files such as "europe" a bit shorter and
4826 should ease maintenance.)
4829 Release data96f - 1996-04-19 19:20:03 -0000
4830 [tzdata96f.tar.gz is missing!]
4832 The only changes are to the "northamerica" file; the time zone
4833 abbreviation for Denver is corrected to MST (and MDT), and the
4834 comments for Mexico have been updated.
4837 Release data96e - 1996-03-19 17:37:26 -0500
4839 Proposals by Paul Eggert, in particular the Portugal change that
4840 comes into play at the end of this month.
4843 Release data96d - 1996-03-18 20:49:39 -0500
4848 Release code96e - 1996-02-29 15:43:27 -0000
4849 [tzcode96e.tar.gz is missing!]
4851 internationalization changes and the fix to the documentation for strftime
4854 Release code96d-data96c - 1996-02-12 11:05:27 -0500
4856 The "code" file simply updates Bob Kridle's electronic address.
4858 The "data" file updates rules for Mexico.
4861 Release data96b - 1996-01-27 15:44:42 -0500
4866 Release code96c - 1996-01-16 16:58:15 -0500
4868 leap-year streamlining and binary-search changes
4873 Release code96b - 1996-01-10 20:42:39 -0500
4875 fixes and enhancements from Paul Eggert, including code that
4876 emulates the behavior of recent versions of the SunOS "date"
4880 Release 96a - 1996-01-06 09:08:24 -0500
4884 fixes to strftime.c for correct ISO 8601 week number generation,
4885 plus support for two new formats ('G' and 'g') to give ISO 8601 year
4886 numbers (which are not necessarily the same as calendar year numbers)
4889 Release code95i-data95m - 1995-12-21 12:46:47 -0500
4891 The latest revisions from Paul Eggert are included, the usno1995
4892 file has been updated, and a new file ("WWW") covering useful URLs
4896 Release code95h-data95l - 1995-12-19 18:10:12 -0500
4898 A simplification of a macro definition, a change to data for Sudan,
4899 and (for last minute shoppers) notes in the "Music" file on the CD
4903 Release code95g-data95k - 1995-10-30 10:32:47 -0500
4905 (slightly reformatted) 8-bit-clean proposed patch
4907 minor patch: US/Eastern -> America/New_York
4909 snapshot of the USNO's latest data ("usno1995")
4911 some other minor cleanups
4914 Release code95f-data95j - 1995-10-28 21:01:34 -0000
4915 [tzcode95f.tar.gz + tzdata95j.tar.gz are both missing!]
4919 support for 64-bit time_t's
4921 optimization in localtime.c
4924 Release code95e - 1995-10-13 13:23:57 -0400
4926 the mktime change to scan from future to past when trying to find time zone
4930 Release data95i - 1995-09-26 10:43:26 -0400
4932 For Canada/Central, guess that the Sun customer's "one week too
4933 early" was just a approximation, and the true error is one month
4934 too early. This is consistent with the rest of Canada.
4937 Release data95h - 1995-09-21 11:26:48 -0400
4939 latest changes from Paul Eggert
4942 Release code95d - 1995-09-14 11:14:45 -0400
4944 the addition of a "Music" file, which documents four recorded
4945 versions of the tune "Save That Time".
4948 Release data95g - 1995-09-01 17:21:36 -0400
4950 "yearistype" correction
4953 Release data95f - 1995-08-28 20:46:56 -0400
4955 Paul Eggert's change to the australasia file
4958 Release data95e - 1995-07-08 18:02:34 -0400
4960 The only change is a leap second at the end of this year.
4961 Thanks to Bradley White for forwarding news on the leap second.
4964 Release data95d - 1995-07-03 13:26:22 -0400
4966 Paul Eggert's changes
4969 Release data95c - 1995-07-02 19:19:28 -0400
4971 changes to "asia", "backward", "europe", and "southamerica"
4972 (read: northamericacentrics need not apply)
4975 Release code95c - 1995-03-13 14:00:46 -0500
4977 one-line fix for sign extension problems in detzcode
4980 Release 95b - 1995-03-04 11:22:38 -0500
4982 Minor changes in both:
4984 The "code" file contains a workaround for the lack of "unistd.h" in
4985 Microsoft C++ version 7.
4987 The "data" file contains a fixed "Link" for America/Shiprock.
4990 Release 94h - 1994-12-10 12:51:14 -0500
4994 * incorporate the changes to "zdump" and "date" to make changes to
4995 the "TZ" environment variable permanent;
4997 * incorporate the table changes by Paul Eggert;
4999 * include (and document) support for universal time specifications in
5000 data files - but do not (yet) include use of this feature in the
5003 Think of this as "TZ Classic" - the software has been set up not to break if
5004 universal time shows up in its input, and data entries have been
5005 left as is so as not to break existing implementations.
5008 Release data94f - 1994-08-20 12:56:09 -0400
5010 (with thanks!) the latest data updates from Paul Eggert
5013 Release data94e - 1994-06-04 13:13:53 -0400
5018 Release code94g - 1994-05-05 12:14:07 -0400
5020 fix missing "optind.c" and a reference to it in the Makefile
5023 Release code94f - 1994-05-05 13:00:33 -0000
5024 [tzcode94f.tar.gz is missing!]
5026 changes to avoid overflow in difftime, as well as changes to cope
5027 with the 52/53 challenge in strftime
5030 Release code94e - 1994-03-30 23:32:59 -0500
5032 change for the benefit of PCTS
5035 Release 94d - 1994-02-24 15:42:25 -0500
5037 Avoid clashes with POSIX semantics for zones such as GMT+4.
5039 Some other very minor housekeeping is also present.
5042 Release code94c - 1994-02-10 08:52:40 -0500
5044 Fix bug where mkdirs was broken unless you compile with
5045 -fwritable-strings (which is generally losing to do).
5048 Release 94b - 1994-02-07 10:04:33 -0500
5050 work by Paul Eggert who notes:
5052 I found another book of time zone histories by E W Whitman; it's not
5053 as extensive as Shanks but has a few goodies of its own. I used it
5054 to update the tables. I also fixed some more as a result of
5055 correspondence with Adam David and Peter Ilieve, and move some stray
5056 links from 'europe' to 'backward'. I corrected some scanning errors
5059 As far as the code goes, I fixed zic to allow years in the range
5060 INT_MIN to INT_MAX; this fixed a few boundary conditions around 1900.
5061 And I cleaned up the zic documentation a little bit.
5064 Release data94a - 1994-02-03 08:58:54 -0500
5066 It simply incorporates the recently announced leap second into the
5070 Release 93g - 1993-11-22 17:28:27 -0500
5072 Paul Eggert has provided a good deal of historic information (based
5073 on Shanks), and there are some code changes to deal with the buglets
5074 that crawled out in dealing with the new information.
5077 Release 93f - 1993-10-15 12:27:46 -0400
5079 Paul Eggert's changes
5082 Release 93e - 1993-09-05 21:21:44 -0400
5084 This has updated data for Israel, England, and Kwajalein. There's
5085 also an update to "zdump" to cope with Kwajalein's 24-hour jump.
5086 Thanks to Paul Eggert and Peter Ilieve for the changes.
5089 Release 93d - 1993-06-17 23:34:17 -0400
5091 new fix and new data on Israel
5094 Release 93c - 1993-06-06 19:31:55 -0400
5099 Release 93b - 1993-02-02 14:53:58 -0500
5101 updated "leapseconds" file
5104 Release 93 - 1993-01-08 07:01:06 -0500
5106 At kre's suggestion, the package has been split in two - a code piece
5107 (which also includes documentation) that's only of use to folks who
5108 want to recompile things and a data piece useful to anyone who can
5111 The new version has a few changes to the data files, a few
5112 portability changes, and an off-by-one fix (with thanks to
5113 Tom Karzes at deshaw.com for providing a description and a
5117 Release 92c - 1992-11-21 17:35:36 -0000
5118 [tz92c.tar.Z is missing!]
5120 The fallout from the latest round of DST transitions.
5122 There are changes for Portugal, Saskatchewan, and "Pacific-New";
5123 there's also a change to "zic.c" that makes it portable to more systems.
5126 Release 92 - 1992-04-25 18:17:03 -0000
5127 [tz92.tar.Z is missing!]
5129 By popular demand (well, at any rate, following a request by kre at munnari)
5132 The 1989 update of the time zone package featured:
5134 * POSIXization (including interpretation of POSIX-style TZ environment
5135 variables, provided by Guy Harris),
5136 * ANSIfication (including versions of "mktime" and "difftime"),
5137 * SVIDulation (an "altzone" variable)
5138 * MACHination (the "gtime" function)
5139 * corrections to some time zone data (including corrections to the rules
5140 for Great Britain and New Zealand)
5141 * reference data from the United States Naval Observatory for folks who
5142 want to do additional time zones
5143 * and the 1989 data for Saudi Arabia.
5145 (Since this code will be treated as "part of the implementation" in some
5146 places and as "part of the application" in others, there's no good way to
5147 name functions, such as timegm, that are not part of the proposed ANSI C
5148 standard; such functions have kept their old, underscore-free names in this
5151 And the "dysize" function has disappeared; it was present to allow
5152 compilation of the "date" command on old BSD systems, and a version of "date"
5153 is now provided in the package. The "date" command is not created when you
5154 "make all" since it may lack options provided by the version distributed with
5155 your operating system, or may not interact with the system in the same way
5156 the native version does.
5158 Since POSIX frowns on correct leap second handling, the default behavior of
5159 the "zic" command (in the absence of a "-L" option) has been changed to omit
5160 leap second information from its output files.
5166 This file contains copies of the part of each release announcement
5167 that talks about the changes in that release. The text has been
5168 adapted and reformatted for the purposes of this file.
5170 Traditionally a release R consists of a pair of tarball files,
5171 tzcodeR.tar.gz and tzdataR.tar.gz. However, some releases (e.g.,
5172 code2010a, data2012c) consist of just one or the other tarball, and a
5173 few (e.g., code2012c-data2012d) have tarballs with mixed version
5174 numbers. Recent releases also come in an experimental format
5175 consisting of a single tarball tzdb-R.tar.lz with extra data.
5177 Release timestamps are taken from the release's commit (for newer,
5178 Git-based releases), from the newest file in the tarball (for older
5179 releases, where this info is available) or from the email announcing
5180 the release (if all else fails; these are marked with a time zone
5181 abbreviation of -0000 and an "is missing!" comment).
5183 Earlier versions of the code and data were not announced on the tz
5184 list and are not summarized here.
5186 This file is in the public domain.