1 News for the tz database
3 Release 2020f - 2020-12-29 00:17:46 -0800
5 Change to build procedure
7 'make rearguard_tarballs' no longer generates a bad rearguard.zi,
8 fixing a 2020e bug. (Problem reported by Deborah Goldsmith.)
11 Release 2020e - 2020-12-22 15:14:34 -0800
14 Volgograd switches to Moscow time on 2020-12-27 at 02:00.
16 Changes to future timestamps
18 Volgograd changes time zone from +04 to +03 on 2020-12-27 at 02:00.
19 (Thanks to Alexander Krivenyshev and Stepan Golosunov.)
21 Changes to past timestamps
23 Correct many pre-1986 transitions, fixing entries originally
24 derived from Shanks. The fixes include:
25 - Australia: several 1917 through 1971 transitions
26 - Bahamas: several 1941 through 1945 transitions
27 - Bermuda: several 1917 through 1956 transitions
28 - Belize: several 1942 through 1968 transitions
29 - Ghana: several 1915 through 1956 transitions
30 - Israel and Palestine: several 1940 through 1985 transitions
31 - Kenya and adjacent: several 1908 through 1960 transitions
32 - Nigeria and adjacent: correcting LMT in Lagos, and several 1905
33 through 1919 transitions
34 - Seychelles: the introduction of standard time in 1907, not 1906
35 - Vanuatu: DST in 1973-1974, and a corrected 1984 transition
38 Because of the Australia change, Australia/Currie (King Island) is
39 no longer needed, as it is identical to Australia/Hobart for all
40 timestamps since 1970 and was therefore created by mistake.
41 Australia/Currie has been moved to the 'backward' file and its
42 corrected data moved to the 'backzone' file.
44 Changes to past time zone abbreviations and DST flags
46 To better match legislation in Turks and Caicos, the 2015 shift to
47 year-round observance of -04 is now modeled as AST throughout before
48 returning to Eastern Time with US DST in 2018, rather than as
49 maintaining EDT until 2015-11-01. (Thanks to P Chan.)
51 Changes to documentation
53 The zic man page now documents zic's coalescing of transitions
54 when a zone falls back just before DST springs forward.
57 Release 2020d - 2020-10-21 11:24:13 -0700
60 Palestine ends DST earlier than predicted, on 2020-10-24.
62 Changes to past and future timestamps
64 Palestine ends DST on 2020-10-24 at 01:00, instead of 2020-10-31
65 as previously predicted (thanks to Sharef Mustafa.) Its
66 2019-10-26 fall-back was at 00:00, not 01:00 (thanks to Steffen
67 Thorsen.) Its 2015-10-23 transition was at 01:00 not 00:00, and
68 its spring 2020 transition was on March 28 at 00:00, not March 27
69 (thanks to Pierre Cashon.) This affects Asia/Gaza and
70 Asia/Hebron. Assume future spring and fall transitions will be on
71 the Saturday preceding the last Sunday of March and October,
75 Release 2020c - 2020-10-16 11:15:53 -0700
78 Fiji starts DST later than usual, on 2020-12-20.
80 Changes to future timestamps
82 Fiji will start DST on 2020-12-20, instead of 2020-11-08 as
83 previously predicted. DST will still end on 2021-01-17.
84 (Thanks to Raymond Kumar and Alan Mintz.) Assume for now that
85 the later-than-usual start date is a one-time departure from the
88 Changes to build procedure
90 Rearguard tarballs now contain an empty file pacificnew.
91 Some older downstream software expects this file to exist.
92 (Problem reported by Mike Cullinan.)
95 Release 2020b - 2020-10-06 18:35:04 -0700
98 Revised predictions for Morocco's changes starting in 2023.
99 Canada's Yukon changes to -07 on 2020-11-01, not 2020-03-08.
100 Macquarie Island has stayed in sync with Tasmania since 2011.
101 Casey, Antarctica is at +08 in winter and +11 in summer.
102 zic no longer supports -y, nor the TYPE field of Rules.
104 Changes to future timestamps
106 Morocco's spring-forward after Ramadan is now predicted to occur
107 no sooner than two days after Ramadan, instead of one day.
108 (Thanks to Milamber.) The first altered prediction is for 2023,
109 now predicted to spring-forward on April 30 instead of April 23.
111 Changes to past and future timestamps
113 Casey Station, Antarctica has been using +08 in winter and +11 in
114 summer since 2018. The most recent transition from +08 to +11 was
115 2020-10-04 00:01. Also, Macquarie Island has been staying in
116 sync with Tasmania since 2011. (Thanks to Steffen Thorsen.)
118 Changes to past and future time zone abbreviations and DST flags
120 Canada's Yukon, represented by America/Whitehorse and
121 America/Dawson, changes its time zone rules from -08/-07 to
122 permanent -07 on 2020-11-01, not on 2020-03-08 as 2020a had it.
123 This change affects only the time zone abbreviation (MST vs PDT)
124 and daylight saving flag for the period between the two dates.
125 (Thanks to Andrew G. Smith.)
127 Changes to past timestamps
129 Correct several transitions for Hungary for 1918/1983.
130 For example, the 1983-09-25 fall-back was at 01:00, not 03:00.
131 (Thanks to Géza Nyáry.) Also, the 1890 transition to standard
132 time was on 11-01, not 10-01 (thanks to Michael Deckers).
134 The 1891 French transition was on March 16, not March 15. The
135 1911-03-11 French transition was at midnight, not a minute later.
136 Monaco's transitions were on 1892-06-01 and 1911-03-29, not
137 1891-03-15 and 1911-03-11. (Thanks to Michael Deckers.)
141 Support for zic's long-obsolete '-y YEARISTYPE' option has been
142 removed and, with it, so has support for the TYPE field in Rule
143 lines, which is now reserved for compatibility with earlier zic.
144 These features were previously deprecated in release 2015f.
145 (Thanks to Tim Parenti.)
147 zic now defaults to '-b slim' instead of to '-b fat'.
149 zic's new '-l -' and '-p -' options uninstall any existing
150 localtime and posixrules files, respectively.
152 The undocumented and ineffective tzsetwall function has been
155 Changes to build procedure
157 The Makefile now defaults POSIXRULES to '-', so the posixrules
158 feature (obsolete as of 2019b) is no longer installed by default.
160 Changes to documentation and commentary
162 The long-obsolete files pacificnew, systemv, and yearistype.sh have
163 been removed from the distribution. (Thanks to Tim Parenti.)
166 Release 2020a - 2020-04-23 16:03:47 -0700
169 Morocco springs forward on 2020-05-31, not 2020-05-24.
170 Canada's Yukon advanced to -07 year-round on 2020-03-08.
171 America/Nuuk renamed from America/Godthab.
172 zic now supports expiration dates for leap second lists.
174 Changes to future timestamps
176 Morocco's second spring-forward transition in 2020 will be May 31,
177 not May 24 as predicted earlier. (Thanks to Semlali Naoufal.)
178 Adjust future-year predictions to use the first Sunday after the
179 day after Ramadan, not the first Sunday after Ramadan.
181 Canada's Yukon, represented by America/Whitehorse and
182 America/Dawson, advanced to -07 year-round, beginning with its
183 spring-forward transition on 2020-03-08, and will not fall back on
184 2020-11-01. Although a government press release calls this
185 "permanent Pacific Daylight Saving Time", we prefer MST for
186 consistency with nearby Dawson Creek, Creston, and Fort Nelson.
187 (Thanks to Tim Parenti.)
189 Changes to past timestamps
191 Shanghai observed DST in 1919. (Thanks to Phake Nick.)
193 Changes to timezone identifiers
195 To reflect current usage in English better, America/Godthab has
196 been renamed to America/Nuuk. A backwards-compatibility link
197 remains for the old name.
201 localtime.c no longer mishandles timestamps after the last
202 transition in a TZif file with leap seconds and with daylight
203 saving time transitions projected into the indefinite future.
204 For example, with TZ='America/Los_Angeles' with leap seconds,
205 zdump formerly reported a DST transition on 2038-03-14
206 from 01:59:32.999... to 02:59:33 instead of the correct transition
207 from 01:59:59.999... to 03:00:00.
209 zic -L now supports an Expires line in the leapseconds file, and
210 truncates the TZif output accordingly. This propagates leap
211 second expiration information into the TZif file, and avoids the
212 abovementioned localtime.c bug as well as similar bugs present in
213 many client implementations. If no Expires line is present, zic
214 -L instead truncates the TZif output based on the #expires comment
215 present in leapseconds files distributed by tzdb 2018f and later;
216 however, this usage is obsolescent. For now, the distributed
217 leapseconds file has an Expires line that is commented out, so
218 that the file can be fed to older versions of zic which ignore the
219 commented-out line. Future tzdb distributions are planned to
220 contain a leapseconds file with an Expires line.
222 The configuration macros HAVE_TZNAME and USG_COMPAT should now be
223 set to 1 if the system library supports the feature, and 2 if not.
224 As before, these macros are nonzero if tzcode should support the
225 feature, zero otherwise.
227 The configuration macro ALTZONE now has the same values with the
228 same meaning as HAVE_TZNAME and USG_COMPAT.
230 The code's defense against CRLF in leap-seconds.list is now
231 portable to POSIX awk. (Problem reported by Deborah Goldsmith.)
233 Although the undocumented tzsetwall function is not changed in
234 this release, it is now deprecated in preparation for removal in
235 future releases. Due to POSIX requirements, tzsetwall has not
236 worked for some time. Any code that uses it should instead use
237 tzalloc(NULL) or, if portability trumps thread-safety, should
238 unset the TZ environment variable.
240 Changes to commentary
242 The Îles-de-la-Madeleine and the Listuguj reserve are noted as
243 following America/Halifax, and comments about Yukon's "south" and
244 "north" have been corrected to say "east" and "west". (Thanks to
248 Release 2019c - 2019-09-11 08:59:48 -0700
251 Fiji observes DST from 2019-11-10 to 2020-01-12.
252 Norfolk Island starts observing Australian-style DST.
254 Changes to future timestamps
256 Fiji's next DST transitions will be 2019-11-10 and 2020-01-12
257 instead of 2019-11-03 and 2020-01-19. (Thanks to Raymond Kumar.)
258 Adjust future guesses accordingly.
260 Norfolk Island will observe Australian-style DST starting in
261 spring 2019. The first transition is on 2019-10-06. (Thanks to
262 Kyle Czech and Michael Deckers.)
264 Changes to past timestamps
266 Many corrections to time in Turkey from 1940 through 1985.
267 (Thanks to Oya Vulaş via Alois Treindl, and to Kıvanç Yazan.)
269 The Norfolk Island 1975-03-02 transition was at 02:00 standard
270 time, not 02:00 DST. (Thanks to Michael Deckers.)
272 South Korea observed DST from 1948 through 1951. Although this
273 info was supposed to appear in release 2014j, a typo inadvertently
274 suppressed the change. (Thanks to Alois Treindl.)
276 Detroit observed DST in 1967 and 1968 following the US DST rules,
277 except that its 1967 DST began on June 14 at 00:01. (Thanks to
278 Alois Treindl for pointing out that the old data entries were
281 Fix several errors in pre-1970 transitions in Perry County, IN.
282 (Thanks to Alois Triendl for pointing out the 1967/9 errors.)
284 Edmonton did not observe DST in 1967 or 1969. In 1946 Vancouver
285 ended DST on 09-29 not 10-13, and Vienna ended DST on 10-07 not
286 10-06. In 1945 Königsberg (now Kaliningrad) switched from +01/+02
287 to +02/+03 on 04-10 not 01-01, and its +02/+03 is abbreviated
288 EET/EEST, not CET/CEST. (Thanks to Alois Triendl.) In 1946
289 Königsberg switched to +03 on 04-07 not 01-01.
291 In 1946 Louisville switched from CST to CDT on 04-28 at 00:01, not
292 01-01 at 00:00. (Thanks to Alois Treindl and Michael Deckers.)
293 Also, it switched from CST to CDT on 1950-04-30, not 1947-04-27.
295 The 1892-05-01 transition in Brussels was at 00:17:30, not at noon.
296 (Thanks to Michael Deckers.)
298 Changes to past time zone abbreviations and DST flags
300 Hong Kong Winter Time, observed from 1941-10-01 to 1941-12-25,
301 is now flagged as DST and is abbreviated HKWT not HKT.
305 leapseconds.awk now relies only on its input data, rather than
306 also relying on its comments. (Inspired by code from Dennis
307 Ferguson and Chris Woodbury.)
309 The code now defends against CRLFs in leap-seconds.list.
310 (Thanks to Brian Inglis and Chris Woodbury.)
312 Changes to documentation and commentary
314 theory.html discusses leap seconds. (Thanks to Steve Summit.)
316 Nashville's newspapers dueled about the time of day in the 1950s.
317 (Thanks to John Seigenthaler.)
319 Liechtenstein observed Swiss DST in 1941/2.
320 (Thanks to Alois Treindl.)
323 Release 2019b - 2019-07-01 00:09:53 -0700
326 Brazil no longer observes DST.
327 'zic -b slim' outputs smaller TZif files; please try it out.
328 Palestine's 2019 spring-forward transition was on 03-29, not 03-30.
330 Changes to future timestamps
332 Brazil has canceled DST and will stay on standard time indefinitely.
333 (Thanks to Steffen Thorsen, Marcus Diniz, and Daniel Soares de
336 Predictions for Morocco now go through 2087 instead of 2037, to
337 work around a problem on newlib when using TZif files output by
338 zic 2019a or earlier. (Problem reported by David Gauchard.)
340 Changes to past and future timestamps
342 Palestine's 2019 spring transition was 03-29 at 00:00, not 03-30
343 at 01:00. (Thanks to Sharef Mustafa and Even Scharning.) Guess
344 future transitions to be March's last Friday at 00:00.
346 Changes to past timestamps
348 Hong Kong's 1941-06-15 spring-forward transition was at 03:00, not
349 03:30. Its 1945 transition from JST to HKT was on 11-18 at 02:00,
350 not 09-15 at 00:00. In 1946 its spring-forward transition was on
351 04-21 at 00:00, not the previous day at 03:30. From 1946 through
352 1952 its fall-back transitions occurred at 04:30, not at 03:30.
353 In 1947 its fall-back transition was on 11-30, not 12-30.
356 Changes to past time zone abbreviations
358 Italy's 1866 transition to Rome Mean Time was on December 12, not
359 September 22. This affects only the time zone abbreviation for
360 Europe/Rome between those dates. (Thanks to Stephen Trainor and
363 Changes affecting metadata only
365 Add info about the Crimea situation in zone1970.tab and zone.tab.
366 (Problem reported by Serhii Demediuk.)
370 zic's new -b option supports a way to control data bloat and to
371 test for year-2038 bugs in software that reads TZif files.
372 'zic -b fat' and 'zic -b slim' generate larger and smaller output;
373 for example, changing from fat to slim shrinks the Europe/London
374 file from 3648 to 1599 bytes, saving about 56%. Fat and slim
375 files represent the same set of timestamps and use the same TZif
376 format as documented in tzfile(5) and in Internet RFC 8536.
377 Fat format attempts to work around bugs or incompatibilities in
378 older software, notably software that mishandles 64-bit TZif data
379 or uses obsolete TZ strings like "EET-2EEST" that lack DST rules.
380 Slim format is more efficient and does not work around 64-bit bugs
381 or obsolete TZ strings. Currently zic defaults to fat format
382 unless you compile with -DZIC_BLOAT_DEFAULT=\"slim\"; this
383 out-of-the-box default is intended to change in future releases
384 as the buggy software often mishandles timestamps anyway.
386 zic no longer treats a set of rules ending in 2037 specially.
387 Previously, zic assumed that such a ruleset meant that future
388 timestamps could not be predicted, and therefore omitted a
389 POSIX-like TZ string in the TZif output. The old behavior is no
390 longer needed for current tzdata, and caused problems with newlib
391 when used with older tzdata (reported by David Gauchard).
393 zic no longer generates some artifact transitions. For example,
394 Europe/London no longer has a no-op transition in January 1996.
396 Changes to build procedure
398 tzdata.zi now assumes zic 2017c or later. This shrinks tzdata.zi
401 Changes to documentation and commentary
403 The Makefile now documents the POSIXRULES macro as being obsolete,
404 and similarly, zic's -p POSIXRULES option is now documented as
405 being obsolete. Although the POSIXRULES feature still exists and
406 works as before, in practice it is rarely used for its intended
407 purpose, and it does not work either in the default reference
408 implementation (for timestamps after 2037) or in common
409 implementations such as GNU/Linux (for contemporary timestamps).
410 Since POSIXRULES was designed primarily as a temporary transition
411 facility for System V platforms that died off decades ago, it is
412 being decommissioned rather than institutionalized.
414 New info on Bonin Islands and Marcus (thanks to Wakaba and Phake Nick).
417 Release 2019a - 2019-03-25 22:01:33 -0700
420 Palestine "springs forward" on 2019-03-30 instead of 2019-03-23.
421 Metlakatla "fell back" to rejoin Alaska Time on 2019-01-20 at 02:00.
423 Changes to past and future timestamps
425 Palestine will not start DST until 2019-03-30, instead of 2019-03-23 as
426 previously predicted. Adjust our prediction by guessing that spring
427 transitions will be between 24 and 30 March, which matches recent practice
428 since 2016. (Thanks to Even Scharning and Tim Parenti.)
430 Metlakatla ended its observance of Pacific standard time,
431 rejoining Alaska Time, on 2019-01-20 at 02:00. (Thanks to Ryan
432 Stanley and Tim Parenti.)
434 Changes to past timestamps
436 Israel observed DST in 1980 (08-02/09-13) and 1984 (05-05/08-25).
437 (Thanks to Alois Treindl and Isaac Starkman.)
439 Changes to time zone abbreviations
441 Etc/UCT is now a backward-compatibility link to Etc/UTC, instead
442 of being a separate zone that generates the abbreviation "UCT",
443 which nowadays is typically a typo. (Problem reported by Isiah
448 zic now has an -r option to limit the time range of output data.
449 For example, 'zic -r @1000000000' limits the output data to
450 timestamps starting 1000000000 seconds after the Epoch.
451 This helps shrink output size and can be useful for applications
452 not needing the full timestamp history, such as TZDIST truncation;
453 see Internet RFC 8536 section 5.1. (Inspired by a feature request
454 from Christopher Wong, helped along by bug reports from Wong and
457 Changes to documentation
459 Mention Internet RFC 8536 (February 2019), which documents TZif.
461 tz-link.html now cites tzdata-meta
462 <https://tzdata-meta.timtimeonline.com/>.
465 Release 2018i - 2018-12-30 11:05:43 -0800
468 São Tomé and Príncipe switches from +01 to +00 on 2019-01-01.
470 Changes to future timestamps
472 Due to a change in government, São Tomé and Príncipe switches back
473 from +01 to +00 on 2019-01-01 at 02:00. (Thanks to Vadim
474 Nasardinov and Michael Deckers.)
477 Release 2018h - 2018-12-23 17:59:32 -0800
480 Qyzylorda, Kazakhstan moved from +06 to +05 on 2018-12-21.
481 New zone Asia/Qostanay because Qostanay, Kazakhstan didn't move.
482 Metlakatla, Alaska observes PST this winter only.
483 Guess Morocco will continue to adjust clocks around Ramadan.
484 Add predictions for Iran from 2038 through 2090.
486 Changes to future timestamps
488 Guess that Morocco will continue to fall back just before and
489 spring forward just after Ramadan, the practice since 2012.
490 (Thanks to Maamar Abdelkader.) This means Morocco will observe
491 negative DST during Ramadan in main and vanguard formats, and in
492 rearguard format it stays in the +00 timezone and observes
493 ordinary DST in all months other than Ramadan. As before, extend
494 this guesswork to the year 2037. As a consequence, Morocco is
495 scheduled to observe three DST transitions in some Gregorian years
496 (e.g., 2033) due to the mismatch between the Gregorian and Islamic
499 The table of exact transitions for Iranian DST has been extended.
500 It formerly cut off before the year 2038 in a nod to 32-bit time_t.
501 It now cuts off before 2091 as there is doubt about how the Persian
502 calendar will treat 2091. This change predicts DST transitions in
503 2038-9, 2042-3, and 2046-7 to occur one day later than previously
504 predicted. As before, post-cutoff transitions are approximated.
506 Changes to past and future timestamps
508 Qyzylorda (aka Kyzylorda) oblast in Kazakhstan moved from +06 to
509 +05 on 2018-12-21. This is a zone split as Qostanay (aka
510 Kostanay) did not switch, so create a zone Asia/Qostanay.
512 Metlakatla moved from Alaska to Pacific standard time on 2018-11-04.
513 It did not change clocks that day and remains on -08 this winter.
514 (Thanks to Ryan Stanley.) It will revert to the usual Alaska
515 rules next spring, so this change affects only timestamps
516 from 2018-11-04 through 2019-03-10.
518 Change to past timestamps
520 Kwajalein's 1993-08-20 transition from -12 to +12 was at 24:00,
521 not 00:00. I transcribed the time incorrectly from Shanks.
522 (Thanks to Phake Nick.)
524 Nauru's 1979 transition was on 02-10 at 02:00, not 05-01 at 00:00.
525 (Thanks to Phake Nick.)
527 Guam observed DST irregularly from 1959 through 1977.
528 (Thanks to Phake Nick.)
530 Hong Kong observed DST in 1941 starting 06-15 (not 04-01), then on
531 10-01 changed standard time to +08:30 (not +08). Its transition
532 back to +08 after WWII was on 1945-09-15, not the previous day.
533 Its 1904-10-30 change took effect at 01:00 +08 (not 00:00 LMT).
534 (Thanks to Phake Nick, Steve Allen, and Joseph Myers.) Also,
535 its 1952 fallback was on 11-02 (not 10-25).
537 This release contains many changes to timestamps before 1946 due
538 to Japanese possession or occupation of Pacific/Chuuk,
539 Pacific/Guam, Pacific/Kosrae, Pacific/Kwajalein, Pacific/Majuro,
540 Pacific/Nauru, Pacific/Palau, and Pacific/Pohnpei.
541 (Thanks to Phake Nick.)
543 Assume that the Spanish East Indies was like the Philippines and
544 observed American time until the end of 1844. This affects
545 Pacific/Chuuk, Pacific/Kosrae, Pacific/Palau, and Pacific/Pohnpei.
547 Changes to past tm_isdst flags
549 For the recent Morocco change, the tm_isdst flag should be 1 from
550 2018-10-27 00:00 to 2018-10-28 03:00. (Thanks to Michael Deckers.)
551 Give a URL to the official decree. (Thanks to Matt Johnson.)
554 Release 2018g - 2018-10-26 22:22:45 -0700
557 Morocco switches to permanent +01 on 2018-10-28.
559 Changes to future timestamps
561 Morocco switches from +00/+01 to permanent +01 effective 2018-10-28,
562 so its clocks will not fall back as previously scheduled.
563 (Thanks to Mohamed Essedik Najd and Brian Inglis.)
567 When generating TZif files with leap seconds, zic no longer uses a
568 format that trips up older 32-bit clients, fixing a bug introduced
569 in 2018f. (Reported by Daniel Fischer.) Also, the zic workaround
570 for QTBUG-53071 now also works for TZif files with leap seconds.
572 The translator to rearguard format now rewrites the line
573 "Rule Japan 1948 1951 - Sep Sat>=8 25:00 0 S" to
574 "Rule Japan 1948 1951 - Sep Sun>=9 1:00 0 S".
575 This caters to zic before 2007 and to Oracle TZUpdater 2.2.0
576 and earlier. (Reported by Christos Zoulas.)
578 Changes to past time zone abbreviations
580 Change HDT to HWT/HPT for WWII-era abbreviations in Hawaii.
581 This reverts to 2011h, as the abbreviation change in 2011i was
584 Changes to documentation
586 tzfile.5 has new sections on interoperability issues.
589 Release 2018f - 2018-10-18 00:14:18 -0700
592 Volgograd moves from +03 to +04 on 2018-10-28.
593 Fiji ends DST 2019-01-13, not 2019-01-20.
594 Most of Chile changes DST dates, effective 2019-04-06.
596 Changes to future timestamps
598 Volgograd moves from +03 to +04 on 2018-10-28 at 02:00.
599 (Thanks to Alexander Fetisov and Stepan Golosunov.)
601 Fiji ends DST 2019-01-13 instead of the 2019-01-20 previously
602 predicted. (Thanks to Raymond Kumar.) Adjust future predictions
605 Most of Chile will end DST on the first Saturday in April at 24:00 mainland
606 time, and resume DST on the first Saturday in September at 24:00 mainland
607 time. The changes are effective from 2019-04-06, and do not affect the
608 Magallanes region modeled by America/Punta_Arenas. (Thanks to Juan Correa
609 and Tim Parenti.) Adjust future predictions accordingly.
611 Changes to past timestamps
613 The 2018-05-05 North Korea 30-minute time zone change took place
614 at 23:30 the previous day, not at 00:00 that day.
616 China's 1988 spring-forward transition was on April 17, not
617 April 10. Its DST transitions in 1986/91 were at 02:00, not 00:00.
620 Fix several issues for Macau before 1992. Macau's pre-1904 LMT
621 was off by 10 s. Macau switched to +08 in 1904 not 1912, and
622 temporarily switched to +09/+10 during World War II. Macau
623 observed DST in 1942/79, not 1961/80, and there were several
624 errors for transition times and dates. (Thanks to P Chan.)
626 The 1948-1951 fallback transitions in Japan were at 25:00 on
627 September's second Saturday, not at 24:00. (Thanks to Phake Nick.)
628 zic turns this into 01:00 on the day after September's second
629 Saturday, which is the best that POSIX or C platforms can do.
631 Incorporate 1940-1949 Asia/Shanghai DST transitions from a 2014
632 paper by Li Yu, replacing more-questionable data from Shanks.
634 Changes to time zone abbreviations
636 Use "PST" and "PDT" for Philippine time. (Thanks to Paul Goyette.)
640 zic now always generates TZif files where time type 0 is used for
641 timestamps before the first transition. This simplifies the
642 reading of TZif files and should not affect behavior of existing
643 TZif readers because the same set of time types is used; only
644 their internal indexes may have changed. This affects only the
645 legacy zones EST5EDT, CST6CDT, MST7MDT, PST8PDT, CET, MET, and
646 EET, which previously used nonzero types for these timestamps.
648 Because of the type 0 change, zic no longer outputs a dummy
649 transition at time -2**59 (before the Big Bang), as clients should
650 no longer need this to handle historical timestamps correctly.
651 This reverts a change introduced in 2013d and shrinks most TZif
652 files by a few bytes.
654 zic now supports negative time-of-day in Rule and Leap lines, e.g.,
655 "Rule X min max - Apr lastSun -6:00 1:00 -" means the transition
656 occurs at 18:00 on the Saturday before the last Sunday in April.
657 This behavior was documented in 2018a but the code did not
658 entirely match the documentation.
660 localtime.c no longer requires at least one time type in TZif
661 files that lack transitions or have a POSIX-style TZ string. This
662 future-proofs the code against possible future extensions to the
663 format that would allow TZif files with POSIX-style TZ strings and
664 without transitions or time types.
666 A read-access subscript error in localtime.c has been fixed.
667 It could occur only in TZif files with timecnt == 0, something that
668 does not happen in practice now but could happen in future versions.
670 localtime.c no longer ignores TZif POSIX-style TZ strings that
671 specify only standard time. Instead, these TZ strings now
672 override the default time type for timestamps after the last
673 transition (or for all timestamps if there are no transitions),
674 just as DST strings specifying DST have always done.
676 leapseconds.awk now outputs "#updated" and "#expires" comments,
677 and supports leap seconds at the ends of months other than June
678 and December. (Inspired by suggestions from Chris Woodbury.)
680 Changes to documentation
682 New restrictions: A Rule name must start with a character that
683 is neither an ASCII digit nor "-" nor "+", and an unquoted name
684 should not use characters in the set "!$%&'()*,/:;<=>?@[\]^`{|}~".
685 The latter restriction makes room for future extensions (a
686 possibility noted by Tom Lane).
688 tzfile.5 now documents what time types apply before the first and
689 after the last transition, if any.
691 Documentation now uses the spelling "timezone" for a TZ setting
692 that determines timestamp history, and "time zone" for a
693 geographic region currently sharing the same standard time.
695 The name "TZif" is now used for the tz binary data format.
697 tz-link.htm now mentions the A0 TimeZone Migration utilities.
698 (Thanks to Aldrin Martoq for the link.)
700 Changes to build procedure
702 New 'make' target 'rearguard_tarballs' to build the rearguard
703 tarball only. This is a convenience on platforms that lack lzip
704 if you want to build the rearguard tarball. (Problem reported by
707 tzdata.zi is now more stable from release to release. (Problem
708 noted by Tom Lane.) It is also a bit shorter.
710 tzdata.zi now can contain comment lines documenting configuration
711 information, such as which data format was selected, which input
712 files were used, and how leap seconds are treated. (Problems
713 noted by Lester Caine and Brian Inglis.) If the Makefile defaults
714 are used these comment lines are absent, for backward
715 compatibility. A redistributor intending to alter its copy of the
716 files should also append "-LABEL" to the 'version' file's first
717 line, where "LABEL" identifies the redistributor's change.
720 Release 2018e - 2018-05-01 23:42:51 -0700
724 North Korea switches back to +09 on 2018-05-05.
725 The main format uses negative DST again, for Ireland etc.
726 'make tarballs' now also builds a rearguard tarball.
727 New 's' and 'd' suffixes in SAVE columns of Rule and Zone lines.
729 Changes to past and future timestamps
731 North Korea switches back from +0830 to +09 on 2018-05-05.
732 (Thanks to Kang Seonghoon, Arthur David Olson, Seo Sanghyeon,
735 Bring back the negative-DST changes of 2018a, except be more
736 compatible with data parsers that do not support negative DST.
737 Also, this now affects historical timestamps in Namibia and the
738 former Czechoslovakia, not just Ireland. The main format now uses
739 negative DST to model timestamps in Europe/Dublin (from 1971 on),
740 Europe/Prague (1946/7), and Africa/Windhoek (1994/2017). This
741 does not affect UT offsets, only time zone abbreviations and the
742 tm_isdst flag. Also, this does not affect rearguard or vanguard
743 formats; effectively the main format now uses vanguard instead of
744 rearguard format. Data parsers that do not support negative DST
745 can still use data from the rearguard tarball described below.
747 Changes to build procedure
749 The command 'make tarballs' now also builds the tarball
750 tzdataVERSION-rearguard.tar.gz, which is like tzdataVERSION.tar.gz
751 except that it uses rearguard format intended for trailing-edge
754 Changes to data format and to code
756 The SAVE column of Rule and Zone lines can now have an 's' or 'd'
757 suffix, which specifies whether the adjusted time is standard time
758 or daylight saving time. If no suffix is given, daylight saving
759 time is used if and only if the SAVE column is nonzero; this is
760 the longstanding behavior. Although this new feature is not used
761 in tzdata, it could be used to specify the legal time in Namibia
762 1994-2017, as opposed to the popular time (see below).
764 Changes to past timestamps
766 From 1994 through 2017 Namibia observed DST in winter, not summer.
767 That is, it used negative DST, as Ireland still does. This change
768 does not affect UTC offsets; it affects only the tm_isdst flag and
769 the abbreviation used during summer, which is now CAT, not WAST.
770 Although (as noted by Michael Deckers) summer and winter time were
771 both simply called "standard time" in Namibian law, in common
772 practice winter time was considered to be DST (as noted by Stephen
773 Colebourne). The full effect of this change is only in vanguard
774 and main format; in rearguard format, the tm_isdst flag is still
775 zero in winter and nonzero in summer.
777 In 1946/7 Czechoslovakia also observed negative DST in winter.
778 The full effect of this change is only in vanguard and main
779 formats; in rearguard format, it is modeled as plain GMT without
780 daylight saving. Also, the dates of some 1944/5 DST transitions
781 in Czechoslovakia have been changed.
784 Release 2018d - 2018-03-22 07:05:46 -0700
788 Palestine starts DST a week earlier in 2018.
789 Add support for vanguard and rearguard data consumers.
790 Add subsecond precision to source data format, though not to data.
792 Changes to future timestamps
794 In 2018, Palestine starts DST on March 24, not March 31.
795 Adjust future predictions accordingly. (Thanks to Sharef Mustafa.)
797 Changes to past and future timestamps
799 Casey Station in Antarctica changed from +11 to +08 on 2018-03-11
800 at 04:00. (Thanks to Steffen Thorsen.)
802 Changes to past timestamps
804 Historical transitions for Uruguay, represented by
805 America/Montevideo, have been updated per official legal documents,
806 replacing previous data mainly originating from the inventions of
807 Shanks & Pottenger. This has resulted in adjustments ranging from
808 30 to 90 minutes in either direction over at least two dozen
809 distinct periods ranging from one day to several years in length.
810 A mere handful of pre-1991 transitions are unaffected; data since
811 then has come from more reliable contemporaneous reporting. These
812 changes affect various timestamps in 1920-1923, 1936, 1939,
813 1942-1943, 1959, 1966-1970, 1972, 1974-1980, and 1988-1990.
814 Additionally, Uruguay's pre-standard-time UT offset has been
815 adjusted westward by 7 seconds, from UT-03:44:44 to UT-03:44:51, to
816 match the location of the Observatory of the National Meteorological
817 Institute in Montevideo.
818 (Thanks to Jeremie Bonjour, Tim Parenti, and Michael Deckers.)
820 Enderbury and Kiritimati skipped New Year's Eve 1994, not
821 New Year's Day 1995. (Thanks to Kerry Shetline.)
823 Fix the 1912-01-01 transition for Portugal and its colonies.
824 This transition was at 00:00 according to the new UT offset, not
825 according to the old one. Also assume that Cape Verde switched on
826 the same date as the rest, not in 1907. This affects
827 Africa/Bissau, Africa/Sao_Tome, Asia/Macau, Atlantic/Azores,
828 Atlantic/Cape_Verde, Atlantic/Madeira, and Europe/Lisbon.
829 (Thanks to Michael Deckers.)
831 Fix an off-by-1 error for pre-1913 timestamps in Jamaica and in
834 Changes to past time zone abbreviations
836 MMT took effect in Uruguay from 1908-06-10, not 1898-06-28. There
837 is no clock change associated with the transition.
839 Changes to build procedure
841 The new DATAFORM macro in the Makefile lets the installer choose
842 among three source data formats. The idea is to lessen downstream
843 disruption when data formats are improved.
845 * DATAFORM=vanguard installs from the latest, bleeding-edge
846 format. DATAFORM=main (the default) installs from the format
847 used in the 'africa' etc. files. DATAFORM=rearguard installs
848 from a trailing-edge format. Eventually, elements of today's
849 vanguard format should move to the main format, and similarly
850 the main format's features should eventually move to the
853 * In the current version, the main and rearguard formats are
854 identical and match that of 2018c, so this change does not
855 affect default behavior. The vanguard format currently contains
856 one feature not in the main format: negative SAVE values. This
857 improves support for Ireland, which uses Irish Standard Time
858 (IST, UTC+01) in summer and GMT (UTC) in winter. tzcode has
859 supported negative SAVE values for decades, and this feature
860 should move to the main format soon. However, it will not move
861 to the rearguard format for quite some time because some
862 downstream parsers do not support it.
864 * The build procedure constructs three files vanguard.zi, main.zi,
865 and rearguard.zi, one for each format. Although the files
866 represent essentially the same data, they may have minor
867 discrepancies that users are not likely to notice. The files
868 are intended for downstream data consumers and are not
869 installed. Zoneinfo parsers that do not support negative SAVE values
870 should start using rearguard.zi, so that they will be unaffected
871 when the negative-DST feature moves from vanguard to main.
872 Bleeding-edge Zoneinfo parsers that support the new features
873 already can use vanguard.zi; in this respect, current tzcode is
876 The Makefile should now be safe for parallelized builds, and 'make
877 -j to2050new.tzs' is now much faster on a multiprocessor host
880 When built with -DSUPPRESS_TZDIR, the tzcode library no longer
881 prepends TZDIR/ to file names that do not begin with '/'. This is
882 not recommended for general use, due to its security implications.
883 (From a suggestion by Manuela Friedrich.)
887 zic now accepts subsecond precision in expressions like
888 00:19:32.13, which is approximately the legal time of the
889 Netherlands from 1835 to 1937. However, because it is
890 questionable whether the few recorded uses of non-integer offsets
891 had subsecond precision in practice, there are no plans for tzdata
892 to use this feature. (Thanks to Steve Allen for pointing out
893 the limitations of historical data in this area.)
895 The code is a bit more portable to MS-Windows. Installers can
896 compile with -DRESERVE_STD_EXT_IDS on MS-Windows platforms that
897 reserve identifiers like 'localtime'. (Thanks to Manuela
900 Changes to documentation and commentary
902 theory.html now outlines tzdb's extensions to POSIX's model for
903 civil time, and has a section "POSIX features no longer needed"
904 that lists POSIX API components that are now vestigial.
905 (From suggestions by Steve Summit.) It also better distinguishes
906 time zones from tz regions. (From a suggestion by Guy Harris.)
908 Commentary is now more consistent about using the phrase "daylight
909 saving time", to match the C name tm_isdst. Daylight saving time
910 need not occur in summer, and need not have a positive offset from
913 Commentary about historical transitions in Uruguay has been expanded
914 with links to many relevant legal documents.
915 (Thanks to Tim Parenti.)
917 Commentary now uses some non-ASCII characters with Unicode value
918 less than U+0100, as they can be useful and should work even with
919 older editors such as XEmacs.
922 Release 2018c - 2018-01-22 23:00:44 -0800
925 Revert Irish changes that relied on negative SAVE values.
929 Revert the 2018a change to Europe/Dublin. As before, this change
930 does not affect UT offsets or abbreviations; it affects only
931 whether timestamps are considered to be standard time or
932 daylight-saving time, as expressed in the tm_isdst flag of C's
933 struct tm type. This reversion is intended to be a temporary
934 workaround for problems discovered with downstream uses of
935 releases 2018a and 2018b, which implemented Irish time by using
936 negative SAVE values in the Eire rules of the 'europe' file.
937 Although negative SAVE values have been part of tzcode for many
938 years and are supported by many platforms, they were not
939 documented before 2018a and ICU and OpenJDK do not currently
940 support them. A mechanism to export data to platforms lacking
941 support for negative DST is planned to be developed before the
942 change is reapplied. (Problems reported by Deborah Goldsmith and
945 Changes to past timestamps
947 Japanese DST transitions (1948-1951) were Sundays at 00:00, not
948 Saturdays or Sundays at 02:00. (Thanks to Takayuki Nikai.)
950 Changes to build procedure
952 The build procedure now works around mawk 1.3.3's lack of support
953 for character class expressions. (Problem reported by Ohyama.)
956 Release 2018b - 2018-01-17 23:24:48 -0800
959 Fix a packaging problem in tz2018a, which was missing 'pacificnew'.
961 Changes to build procedure
963 The distribution now contains the file 'pacificnew' again.
964 This file was inadvertantly omitted in the 2018a distribution.
965 (Problem reported by Matias Fonzo.)
968 Release 2018a - 2018-01-12 22:29:21 -0800
971 São Tomé and Príncipe switched from +00 to +01.
972 Brazil's DST will now start on November's first Sunday.
973 Ireland's standard time is now in the summer, not the winter.
974 Use Debian-style installation locations, instead of 4.3BSD-style.
977 Changes to past and future timestamps
979 São Tomé and Príncipe switched from +00 to +01 on 2018-01-01 at
980 01:00. (Thanks to Steffen Thorsen and Michael Deckers.)
982 Changes to future timestamps
984 Starting in 2018 southern Brazil will begin DST on November's
985 first Sunday instead of October's third Sunday. (Thanks to
988 Changes to past timestamps
990 A discrepancy of 4 s in timestamps before 1931 in South Sudan has
991 been corrected. The 'backzone' and 'zone.tab' files did not agree
992 with the 'africa' and 'zone1970.tab' files. (Problem reported by
995 The abbreviation invented for Bolivia Summer Time (1931-2) is now
996 BST instead of BOST, to be more consistent with the convention
997 used for Latvian Summer Time (1918-9) and for British Summer Time.
1001 Change Europe/Dublin so that it observes Irish Standard Time (UT
1002 +01) in summer and GMT (as negative daylight-saving) in winter,
1003 instead of observing standard time (GMT) in winter and Irish
1004 Summer Time (UT +01) in summer. This change does not affect UT
1005 offsets or abbreviations; it affects only whether timestamps are
1006 considered to be standard time or daylight-saving time, as
1007 expressed in the tm_isdst flag of C's struct tm type.
1008 (Discrepancy noted by Derick Rethans.)
1010 Changes to build procedure
1012 The default installation locations have been changed to mostly
1013 match Debian circa 2017, instead of being designed as an add-on to
1014 4.3BSD circa 1986. This affects the Makefile macros TOPDIR,
1015 TZDIR, MANDIR, and LIBDIR. New Makefile macros TZDEFAULT, USRDIR,
1016 USRSHAREDIR, BINDIR, ZDUMPDIR, and ZICDIR let installers tailor
1017 locations more precisely. (This responds to suggestions from
1018 Brian Inglis and from Steve Summit.)
1020 The default installation procedure no longer creates the
1021 backward-compatibility link US/Pacific-New, which causes
1022 confusion during user setup (e.g., see Debian bug 815200).
1023 Use 'make BACKWARD="backward pacificnew"' to create the link
1024 anyway, for now. Eventually we plan to remove the link entirely.
1026 tzdata.zi now contains a version-number comment.
1027 (Suggested by Tom Lane.)
1029 The Makefile now quotes values like BACKWARD more carefully when
1030 passing them to the shell. (Problem reported by Zefram.)
1032 Builders no longer need to specify -DHAVE_SNPRINTF on platforms
1033 that have snprintf and use pre-C99 compilers. (Problem reported
1038 zic has a new option -t FILE that specifies the location of the
1039 file that determines local time when TZ is unset. The default for
1040 this location can be configured via the new TZDEFAULT makefile
1041 macro, which defaults to /etc/localtime.
1043 Diagnostics and commentary now distinguish UT from UTC more
1044 carefully; see theory.html for more information about UT vs UTC.
1046 zic has been ported to GCC 8's -Wstringop-truncation option.
1047 (Problem reported by Martin Sebor.)
1049 Changes to documentation and commentary
1051 The zic man page now documents the longstanding behavior that
1052 times and years can be out of the usual range, with negative times
1053 counting backwards from midnight and with year 0 preceding year 1.
1054 (Problem reported by Michael Deckers.)
1056 The theory.html file now mentions the POSIX limit of six chars
1057 per abbreviation, and lists alphabetic abbreviations used.
1059 The files tz-art.htm and tz-link.htm have been renamed to
1060 tz-art.html and tz-link.html, respectively, for consistency with
1061 other file names and to simplify web server configuration.
1064 Release 2017c - 2017-10-20 14:49:34 -0700
1067 Northern Cyprus switches from +03 to +02/+03 on 2017-10-29.
1068 Fiji ends DST 2018-01-14, not 2018-01-21.
1069 Namibia switches from +01/+02 to +02 on 2018-04-01.
1070 Sudan switches from +03 to +02 on 2017-11-01.
1071 Tonga likely switches from +13/+14 to +13 on 2017-11-05.
1072 Turks & Caicos switches from -04 to -05/-04 on 2018-11-04.
1073 A new file tzdata.zi now holds a small text copy of all data.
1074 The zic input format has been regularized slightly.
1076 Changes to future timestamps
1078 Northern Cyprus has decided to resume EU rules starting
1079 2017-10-29, thus reinstituting winter time.
1081 Fiji ends DST 2018-01-14 instead of the 2018-01-21 previously
1082 predicted. (Thanks to Dominic Fok.) Adjust future predictions
1085 Namibia will switch from +01 with DST to +02 all year on
1086 2017-09-03 at 02:00. This affects UT offsets starting 2018-04-01
1087 at 02:00. (Thanks to Steffen Thorsen.)
1089 Sudan will switch from +03 to +02 on 2017-11-01. (Thanks to Ahmed
1090 Atyya and Yahia Abdalla.) South Sudan is not switching, so
1091 Africa/Juba is no longer a link to Africa/Khartoum.
1093 Tonga has likely ended its experiment with DST, and will not
1094 adjust its clocks on 2017-11-05. Although Tonga has not announced
1095 whether it will continue to observe DST, the IATA is assuming that
1096 it will not. (Thanks to David Wade.)
1098 Turks & Caicos will switch from -04 all year to -05 with US DST on
1099 2018-03-11 at 03:00. This affects UT offsets starting 2018-11-04
1100 at 02:00. (Thanks to Steffen Thorsen.)
1102 Changes to past timestamps
1104 Namibia switched from +02 to +01 on 1994-03-21, not 1994-04-03.
1105 (Thanks to Arthur David Olson.)
1107 Detroit did not observe DST in 1967.
1109 Use railway time for Asia/Kolkata before 1941, by switching to
1110 Madras local time (UT +052110) in 1870, then to IST (UT +0530) in
1111 1906. Also, treat 1941-2's +0630 as DST, like 1942-5.
1113 Europe/Dublin's 1946 and 1947 fallback transitions occurred at
1114 02:00 standard time, not 02:00 DST. (Thanks to Michael Deckers.)
1116 Pacific/Apia and Pacific/Pago_Pago switched from Antipodean to
1117 American time in 1892, not 1879. (Thanks to Michael Deckers.)
1119 Adjust the 1867 transition in Alaska to better reflect the
1120 historical record, by changing it to occur on 1867-10-18 at 15:30
1121 Sitka time rather than at the start of 1867-10-17 local time.
1122 Although strictly speaking this is accurate only for Sitka,
1123 the rest of Alaska's blanks need to be filled in somehow.
1125 Fix off-by-one errors in UT offsets for Adak and Nome before 1867.
1126 (Thanks to Michael Deckers.)
1128 Add 7 s to the UT offset in Asia/Yangon before 1920.
1130 Changes to zone names
1132 Remove Canada/East-Saskatchewan from the 'backward' file, as it
1133 exceeded the 14-character limit and was an unused misnomer anyway.
1135 Changes to build procedure
1137 To support applications that prefer to read time zone data in text
1138 form, two zic input files tzdata.zi and leapseconds are now
1139 installed by default. The commands 'zic tzdata.zi' and 'zic -L
1140 leapseconds tzdata.zi' can reproduce the tzdata binary files
1141 without and with leap seconds, respectively. To prevent these two
1142 new files from being installed, use 'make TZDATA_TEXT=', and to
1143 suppress leap seconds from the tzdata text installation, use 'make
1144 TZDATA_TEXT=tzdata.zi'.
1146 'make BACKWARD=' now suppresses backward-compatibility names
1147 like 'US/Pacific' that are defined in the 'backward' and
1150 'make check' now works on systems that lack a UTF-8 locale,
1151 or that lack the nsgmls program. Set UTF8_LOCALE to configure
1152 the name of a UTF-8 locale, if you have one.
1154 Y2K runtime checks are no longer enabled by default. Add
1155 -DDEPRECATE_TWO_DIGIT_YEARS to CFLAGS to enable them, instead of
1156 adding -DNO_RUN_TIME_WARNINGS_ABOUT_YEAR_2000_PROBLEMS_THANK_YOU
1157 to disable them. (New name suggested by Brian Inglis.)
1159 The build procedure for zdump now works on AIX 7.1.
1160 (Problem reported by Kees Dekker.)
1164 zic and the reference runtime now reject multiple leap seconds
1165 within 28 days of each other, or leap seconds before the Epoch.
1166 As a result, support for double leap seconds, which was
1167 obsolescent and undocumented, has been removed. Double leap
1168 seconds were an error in the C89 standard; they have never existed
1169 in civil timekeeping. (Thanks to Robert Elz and Bradley White for
1170 noticing glitches in the code that uncovered this problem.)
1172 zic now warns about use of the obsolescent and undocumented -y
1173 option, and about use of the obsolescent TYPE field of Rule lines.
1175 zic now allows unambiguous abbreviations like "Sa" and "Su" for
1176 weekdays; formerly it rejected them due to a bug. Conversely, zic
1177 no longer considers non-prefixes to be abbreviations; for example,
1178 it no longer accepts "lF" as an abbreviation for "lastFriday".
1179 Also, zic warns about the undocumented usage with a "last-"
1180 prefix, e.g., "last-Fri".
1182 Similarly, zic now accepts the unambiguous abbreviation "L" for
1183 "Link" in ordinary context and for "Leap" in leap-second context.
1184 Conversely, zic no longer accepts non-prefixes such as "La" as
1185 abbreviations for words like "Leap".
1187 zic no longer accepts leap second lines in ordinary input, or
1188 ordinary lines in leap second input. Formerly, zic sometimes
1189 warned about this undocumented usage and handled it incorrectly.
1191 The new macro HAVE_TZNAME governs whether the tzname external
1192 variable is exported, instead of USG_COMPAT. USG_COMPAT now
1193 governs only the external variables "timezone" and "daylight".
1194 This change is needed because the three variables are not in the
1195 same category: although POSIX requires tzname, it specifies the
1196 other two variables as optional. Also, USG_COMPAT is now 1 or 0:
1197 if not defined, the code attempts to guess it from other macros.
1199 localtime.c and difftime.c no longer require stdio.h, and .c files
1200 other than zic.c no longer require sys/wait.h.
1202 zdump.c no longer assumes snprintf. (Reported by Jonathan Leffler.)
1204 Calculation of time_t extrema works around a bug in GCC 4.8.4
1205 (Reported by Stan Shebs and Joseph Myers.)
1207 zic.c no longer mistranslates formats of line numbers in non-English
1208 locales. (Problem reported by Benno Schulenberg.)
1210 Several minor changes have been made to the code to make it a
1211 bit easier to port to MS-Windows and Solaris. (Thanks to Kees
1212 Dekker for reporting the problems.)
1214 Changes to documentation and commentary
1216 The two new files 'theory.html' and 'calendars' contain the
1217 contents of the removed file 'Theory'. The goal is to document
1218 tzdb theory more accessibly.
1220 The zic man page now documents abbreviation rules.
1222 tz-link.htm now covers how to apply tzdata changes to clients.
1223 (Thanks to Jorge Fábregas for the AIX link.) It also mentions MySQL.
1225 The leap-seconds.list URL has been updated to something that is
1226 more reliable for tzdb. (Thanks to Tim Parenti and Brian Inglis.)
1228 Release 2017b - 2017-03-17 07:30:38 -0700
1230 Briefly: Haiti has resumed DST.
1232 Changes to past and future timestamps
1234 Haiti resumed observance of DST in 2017. (Thanks to Steffen Thorsen.)
1236 Changes to past timestamps
1238 Liberia changed from -004430 to +00 on 1972-01-07, not 1972-05-01.
1240 Use "MMT" to abbreviate Liberia's time zone before 1972, as "-004430"
1241 is one byte over the POSIX limit. (Problem reported by Derick Rethans.)
1245 The reference localtime implementation now falls back on the
1246 current US daylight-saving transition rules rather than the
1247 1987-2006 rules. This fallback occurs only when (1) the TZ
1248 environment variable has a value like "AST4ADT" that asks
1249 for daylight saving time but does not specify the rules, (2) there
1250 is no file by that name, and (3) the TZDEFRULES file cannot be
1251 loaded. (Thanks to Tom Lane.)
1254 Release 2017a - 2017-02-28 00:05:36 -0800
1256 Briefly: Southern Chile moves from -04/-03 to -03, and Mongolia
1259 Changes to future timestamps
1261 Mongolia no longer observes DST. (Thanks to Ganbold Tsagaankhuu.)
1263 Chile's Region of Magallanes moves from -04/-03 to -03 year-round.
1264 Its clocks diverge from America/Santiago starting 2017-05-13 at
1265 23:00, hiving off a new zone America/Punta_Arenas. Although the
1266 Chilean government says this change expires in May 2019, for now
1267 assume it's permanent. (Thanks to Juan Correa and Deborah
1268 Goldsmith.) This also affects Antarctica/Palmer.
1270 Changes to past timestamps
1272 Fix many entries for historical timestamps for Europe/Madrid
1273 before 1979, to agree with tables compiled by Pere Planesas of the
1274 National Astronomical Observatory of Spain. As a side effect,
1275 this changes some timestamps for Africa/Ceuta before 1929, which
1276 are probably guesswork anyway. (Thanks to Steve Allen and
1277 Pierpaolo Bernardi for the heads-ups, and to Michael Deckers for
1278 correcting the 1901 transition.)
1280 Ecuador observed DST from 1992-11-28 to 1993-02-05.
1281 (Thanks to Alois Treindl.)
1283 Asia/Atyrau and Asia/Oral were at +03 (not +04) before 1930-06-21.
1284 (Thanks to Stepan Golosunov.)
1286 Changes to past and future time zone abbreviations
1288 Switch to numeric time zone abbreviations for South America, as
1289 part of the ongoing project of removing invented abbreviations.
1290 This avoids the need to invent an abbreviation for the new Chilean
1291 new zone. Similarly, switch from invented to numeric time zone
1292 abbreviations for Afghanistan, American Samoa, the Azores,
1293 Bangladesh, Bhutan, the British Indian Ocean Territory, Brunei,
1294 Cape Verde, Chatham Is, Christmas I, Cocos (Keeling) Is, Cook Is,
1295 Dubai, East Timor, Eucla, Fiji, French Polynesia, Greenland,
1296 Indochina, Iran, Iraq, Kiribati, Lord Howe, Macquarie, Malaysia,
1297 the Maldives, Marshall Is, Mauritius, Micronesia, Mongolia,
1298 Myanmar, Nauru, Nepal, New Caledonia, Niue, Norfolk I, Palau,
1299 Papua New Guinea, the Philippines, Pitcairn, Qatar, Réunion, St
1300 Pierre & Miquelon, Samoa, Saudi Arabia, Seychelles, Singapore,
1301 Solomon Is, Tokelau, Tuvalu, Wake, Vanuatu, Wallis & Futuna, and
1302 Xinjiang; for 20-minute daylight saving time in Ghana before 1943;
1303 for half-hour daylight saving time in Belize before 1944 and in
1304 the Dominican Republic before 1975; and for Canary Islands before
1305 1946, for Guinea-Bissau before 1975, for Iceland before 1969, for
1306 Indian Summer Time before 1942, for Indonesia before around 1964,
1307 for Kenya before 1960, for Liberia before 1973, for Madeira before
1308 1967, for Namibia before 1943, for the Netherlands in 1937-9, for
1309 Pakistan before 1971, for Western Sahara before 1977, and for
1310 Zaporozhye in 1880-1924.
1312 For Alaska time from 1900 through 1967, instead of "CAT" use the
1313 abbreviation "AST", the abbreviation commonly used at the time
1314 (Atlantic Standard Time had not been standardized yet). Use "AWT"
1315 and "APT" instead of the invented abbreviations "CAWT" and "CAPT".
1317 Use "CST" and "CDT" instead of invented abbreviations for Macau
1318 before 1999 and Taiwan before 1938, and use "JST" instead of the
1319 invented abbreviation "JCST" for Japan and Korea before 1938.
1321 Change to database entry category
1323 Move the Pacific/Johnston link from 'australasia' to 'backward',
1324 since Johnston is now uninhabited.
1328 zic no longer mishandles some transitions in January 2038 when it
1329 attempts to work around Qt bug 53071. This fixes a bug affecting
1330 Pacific/Tongatapu that was introduced in zic 2016e. localtime.c
1331 now contains a workaround, useful when loading a file generated by
1332 a buggy zic. (Problem and localtime.c fix reported by Bradley
1335 zdump -i now outputs non-hour numeric time zone abbreviations
1336 without a colon, e.g., "+0530" rather than "+05:30". This agrees
1337 with zic %z and with common practice, and simplifies auditing of
1340 zdump is now buildable again with -DUSE_LTZ=0.
1341 (Problem reported by Joseph Myers.)
1343 zdump.c now always includes private.h, to avoid code duplication
1344 with private.h. (Problem reported by Kees Dekker.)
1346 localtime.c no longer mishandles early or late timestamps
1347 when TZ is set to a POSIX-style string that specifies DST.
1348 (Problem reported by Kees Dekker.)
1350 date and strftime now cause %z to generate "-0000" instead of
1351 "+0000" when the UT offset is zero and the time zone abbreviation
1354 Changes to documentation and commentary
1356 The 'Theory' file now better documents choice of historical time
1357 zone abbreviations. (Problems reported by Michael Deckers.)
1359 tz-link.htm now covers leap smearing, which is popular in clouds.
1362 Release 2016j - 2016-11-22 23:17:13 -0800
1364 Briefly: Saratov, Russia moves from +03 to +04 on 2016-12-04.
1366 Changes to future timestamps
1368 Saratov, Russia switches from +03 to +04 on 2016-12-04 at 02:00.
1369 This hives off a new zone Europe/Saratov from Europe/Volgograd.
1370 (Thanks to Yuri Konotopov and Stepan Golosunov.)
1372 Changes to past timestamps
1374 The new zone Asia/Atyrau for Atyraū Region, Kazakhstan, is like
1375 Asia/Aqtau except it switched from +05/+06 to +04/+05 in spring
1376 1999, not fall 1994. (Thanks to Stepan Golosunov.)
1378 Changes to past time zone abbreviations
1380 Asia/Gaza and Asia/Hebron now use "EEST", not "EET", to denote
1381 summer time before 1948. The old use of "EET" was a typo.
1385 zic no longer mishandles file systems that lack hard links, fixing
1386 bugs introduced in 2016g. (Problems reported by Tom Lane.)
1387 Also, when the destination already contains symbolic links, zic
1388 should now work better on systems where the 'link' system call
1389 does not follow symbolic links.
1391 Changes to documentation and commentary
1393 tz-link.htm now documents the relationship between release version
1394 numbers and development-repository commit tags. (Suggested by
1397 The 'Theory' file now documents UT.
1399 iso3166.tab now accents "Curaçao", and commentary now mentions
1400 the names "Cabo Verde" and "Czechia". (Thanks to Jiří Boháč.)
1403 Release 2016i - 2016-11-01 23:19:52 -0700
1405 Briefly: Cyprus split into two time zones on 2016-10-30, and Tonga
1406 reintroduces DST on 2016-11-06.
1408 Changes to future timestamps
1410 Pacific/Tongatapu begins DST on 2016-11-06 at 02:00, ending on
1411 2017-01-15 at 03:00. Assume future observances in Tonga will be
1412 from the first Sunday in November through the third Sunday in
1413 January, like Fiji. (Thanks to Pulu ʻAnau.) Switch to numeric
1414 time zone abbreviations for this zone.
1416 Changes to past and future timestamps
1418 Northern Cyprus is now +03 year round, causing a split in Cyprus
1419 time zones starting 2016-10-30 at 04:00. This creates a zone
1420 Asia/Famagusta. (Thanks to Even Scharning and Matt Johnson.)
1422 Antarctica/Casey switched from +08 to +11 on 2016-10-22.
1423 (Thanks to Steffen Thorsen.)
1425 Changes to past timestamps
1427 Several corrections were made for pre-1975 timestamps in Italy.
1428 These affect Europe/Malta, Europe/Rome, Europe/San_Marino, and
1431 First, the 1893-11-01 00:00 transition in Italy used the new UT
1432 offset (+01), not the old (+00:49:56). (Thanks to Michael
1435 Second, rules for daylight saving in Italy were changed to agree
1436 with Italy's National Institute of Metrological Research (INRiM)
1437 except for 1944, as follows (thanks to Pierpaolo Bernardi, Brian
1438 Inglis, and Michael Deckers):
1440 The 1916-06-03 transition was at 24:00, not 00:00.
1442 The 1916-10-01, 1919-10-05, and 1920-09-19 transitions were at
1445 The 1917-09-30 and 1918-10-06 transitions were at 24:00, not
1448 The 1944-09-17 transition was at 03:00, not 01:00. This
1449 particular change is taken from Italian law as INRiM's table,
1450 (which says 02:00) appears to have a typo here. Also, keep the
1451 1944-04-03 transition for Europe/Rome, as Rome was controlled by
1454 The 1967-1970 and 1972-1974 fallback transitions were at 01:00,
1459 The code should now be buildable on AmigaOS merely by setting the
1460 appropriate Makefile variables. (From a patch by Carsten Larsen.)
1463 Release 2016h - 2016-10-19 23:17:57 -0700
1465 Changes to future timestamps
1467 Asia/Gaza and Asia/Hebron end DST on 2016-10-29 at 01:00, not
1468 2016-10-21 at 00:00. (Thanks to Sharef Mustafa.) Predict that
1469 future fall transitions will be on the last Saturday of October
1470 at 01:00, which is consistent with predicted spring transitions
1471 on the last Saturday of March. (Thanks to Tim Parenti.)
1473 Changes to past timestamps
1475 In Turkey, transitions in 1986-1990 were at 01:00 standard time
1476 not at 02:00, and the spring 1994 transition was on March 20, not
1477 March 27. (Thanks to Kıvanç Yazan.)
1479 Changes to past and future time zone abbreviations
1481 Asia/Colombo now uses numeric time zone abbreviations like "+0530"
1482 instead of alphabetic ones like "IST" and "LKT". Various
1483 English-language sources use "IST", "LKT" and "SLST", with no
1484 working consensus. (Usage of "SLST" mentioned by Sadika
1489 zic no longer mishandles relativizing file names when creating
1490 symbolic links like /etc/localtime, when these symbolic links
1491 are outside the usual directory hierarchy. This fixes a bug
1492 introduced in 2016g. (Problem reported by Andreas Stieger.)
1494 Changes to build procedure
1496 New rules 'traditional_tarballs' and 'traditional_signatures' for
1497 building just the traditional-format distribution. (Requested by
1500 The file 'version' is now put into the tzdata tarball too.
1501 (Requested by Howard Hinnant.)
1503 Changes to documentation and commentary
1505 The 'Theory' file now has a section on interface stability.
1506 (Requested by Paul Koning.) It also mentions features like
1507 tm_zone and localtime_rz that have long been supported by the
1510 tz-link.htm has improved coverage of time zone boundaries suitable
1511 for geolocation. (Thanks to heads-ups from Evan Siroky and Matt
1514 The US commentary now mentions Allen and the "day of two noons".
1516 The Fiji commentary mentions the government's 2016-10-03 press
1517 release. (Thanks to Raymond Kumar.)
1520 Release 2016g - 2016-09-13 08:56:38 -0700
1522 Changes to future timestamps
1524 Turkey switched from EET/EEST (+02/+03) to permanent +03,
1525 effective 2016-09-07. (Thanks to Burak AYDIN.) Use "+03" rather
1526 than an invented abbreviation for the new time.
1528 New leap second 2016-12-31 23:59:60 UTC as per IERS Bulletin C 52.
1529 (Thanks to Tim Parenti.)
1531 Changes to past timestamps
1533 For America/Los_Angeles, spring-forward transition times have been
1534 corrected from 02:00 to 02:01 in 1948, and from 02:00 to 01:00 in
1537 For zones using Soviet time on 1919-07-01, transitions to UT-based
1538 time were at 00:00 UT, not at 02:00 local time. The affected
1539 zones are Europe/Kirov, Europe/Moscow, Europe/Samara, and
1540 Europe/Ulyanovsk. (Thanks to Alexander Belopolsky.)
1542 Changes to past and future time zone abbreviations
1544 The Factory zone now uses the time zone abbreviation -00 instead
1545 of a long English-language string, as -00 is now the normal way to
1546 represent an undefined time zone.
1548 Several zones in Antarctica and the former Soviet Union, along
1549 with zones intended for ships at sea that cannot use POSIX TZ
1550 strings, now use numeric time zone abbreviations instead of
1551 invented or obsolete alphanumeric abbreviations. The affected
1552 zones are Antarctica/Casey, Antarctica/Davis,
1553 Antarctica/DumontDUrville, Antarctica/Mawson, Antarctica/Rothera,
1554 Antarctica/Syowa, Antarctica/Troll, Antarctica/Vostok,
1555 Asia/Anadyr, Asia/Ashgabat, Asia/Baku, Asia/Bishkek, Asia/Chita,
1556 Asia/Dushanbe, Asia/Irkutsk, Asia/Kamchatka, Asia/Khandyga,
1557 Asia/Krasnoyarsk, Asia/Magadan, Asia/Omsk, Asia/Sakhalin,
1558 Asia/Samarkand, Asia/Srednekolymsk, Asia/Tashkent, Asia/Tbilisi,
1559 Asia/Ust-Nera, Asia/Vladivostok, Asia/Yakutsk, Asia/Yekaterinburg,
1560 Asia/Yerevan, Etc/GMT-14, Etc/GMT-13, Etc/GMT-12, Etc/GMT-11,
1561 Etc/GMT-10, Etc/GMT-9, Etc/GMT-8, Etc/GMT-7, Etc/GMT-6, Etc/GMT-5,
1562 Etc/GMT-4, Etc/GMT-3, Etc/GMT-2, Etc/GMT-1, Etc/GMT+1, Etc/GMT+2,
1563 Etc/GMT+3, Etc/GMT+4, Etc/GMT+5, Etc/GMT+6, Etc/GMT+7, Etc/GMT+8,
1564 Etc/GMT+9, Etc/GMT+10, Etc/GMT+11, Etc/GMT+12, Europe/Kaliningrad,
1565 Europe/Minsk, Europe/Samara, Europe/Volgograd, and
1566 Indian/Kerguelen. For Europe/Moscow the invented abbreviation MSM
1567 was replaced by +05, whereas MSK and MSD were kept as they are not
1568 our invention and are widely used.
1570 Changes to zone names
1572 Rename Asia/Rangoon to Asia/Yangon, with a backward compatibility link.
1573 (Thanks to David Massoud.)
1577 zic no longer generates binary files containing POSIX TZ-like
1578 strings that disagree with the local time type after the last
1579 explicit transition in the data. This fixes a bug with
1580 Africa/Casablanca and Africa/El_Aaiun in some year-2037 timestamps
1581 on the reference platform. (Thanks to Alexander Belopolsky for
1582 reporting the bug and suggesting a way forward.)
1584 If the installed localtime and/or posixrules files are symbolic
1585 links, zic now keeps them symbolic links when updating them, for
1586 compatibility with platforms like OpenSUSE where other programs
1587 configure these files as symlinks.
1589 zic now avoids hard linking to symbolic links, avoids some
1590 unnecessary mkdir and stat system calls, and uses shorter file
1593 zdump has a new -i option to generate transitions in a
1594 more-compact but still human-readable format. This option is
1595 experimental, and the output format may change in future versions.
1596 (Thanks to Jon Skeet for suggesting that an option was needed,
1597 and thanks to Tim Parenti and Chris Rovick for further comments.)
1599 Changes to build procedure
1601 An experimental distribution format is available, in addition
1602 to the traditional format which will continue to be distributed.
1603 The new format is a tarball tzdb-VERSION.tar.lz with signature
1604 file tzdb-VERSION.tar.lz.asc. It unpacks to a top-level directory
1605 tzdb-VERSION containing the code and data of the traditional
1606 two-tarball format, along with extra data that may be useful.
1607 (Thanks to Antonio Diaz Diaz, Oscar van Vlijmen, and many others
1608 for comments about the experimental format.)
1610 The release version number is now more accurate in the usual case
1611 where releases are built from a Git repository. For example, if
1612 23 commits and some working-file changes have been made since
1613 release 2016g, the version number is now something like
1614 '2016g-23-g50556e3-dirty' instead of the misleading '2016g'.
1615 Tagged releases use the same version number format as before,
1616 e.g., '2016g'. To support the more-accurate version number, its
1617 specification has moved from a line in the Makefile to a new
1618 source file 'version'.
1620 The experimental distribution contains a file to2050.tzs that
1621 contains what should be the output of 'zdump -i -c 2050' on
1622 primary zones. If this file is available, 'make check' now checks
1623 that zdump generates this output.
1625 'make check_web' now works on Fedora-like distributions.
1627 Changes to documentation and commentary
1629 tzfile.5 now documents the new restriction on POSIX TZ-like
1630 strings that is now implemented by zic.
1632 Comments now cite URLs for some 1917-1921 Russian DST decrees.
1633 (Thanks to Alexander Belopolsky.)
1635 tz-link.htm mentions JuliaTime (thanks to Curtis Vogt) and Time4J
1636 (thanks to Meno Hochschild) and ThreeTen-Extra, and its
1637 description of Java 8 has been brought up to date (thanks to
1638 Stephen Colebourne). Its description of local time on Mars has
1639 been updated to match current practice, and URLs have been updated
1640 and some obsolete ones removed.
1643 Release 2016f - 2016-07-05 16:26:51 +0200
1645 Changes affecting future timestamps
1647 The Egyptian government changed its mind on short notice, and
1648 Africa/Cairo will not introduce DST starting 2016-07-07 after all.
1649 (Thanks to Mina Samuel.)
1651 Asia/Novosibirsk switches from +06 to +07 on 2016-07-24 at 02:00.
1652 (Thanks to Stepan Golosunov.)
1654 Changes to past and future timestamps
1656 Asia/Novokuznetsk and Asia/Novosibirsk now use numeric time zone
1657 abbreviations instead of invented ones.
1659 Changes affecting past timestamps
1661 Europe/Minsk's 1992-03-29 spring-forward transition was at 02:00 not 00:00.
1662 (Thanks to Stepan Golosunov.)
1665 Release 2016e - 2016-06-14 08:46:16 -0700
1667 Changes affecting future timestamps
1669 Africa/Cairo observes DST in 2016 from July 7 to the end of October.
1670 Guess October 27 and 24:00 transitions. (Thanks to Steffen Thorsen.)
1671 For future years, guess April's last Thursday to October's last
1672 Thursday except for Ramadan.
1674 Changes affecting past timestamps
1676 Locations while uninhabited now use '-00', not 'zzz', as a
1677 placeholder time zone abbreviation. This is inspired by Internet
1678 RFC 3339 and is more consistent with numeric time zone
1679 abbreviations already used elsewhere. The change affects several
1680 arctic and antarctic locations, e.g., America/Cambridge_Bay before
1681 1920 and Antarctica/Troll before 2005.
1683 Asia/Baku's 1992-09-27 transition from +04 (DST) to +04 (non-DST) was
1684 at 03:00, not 23:00 the previous day. (Thanks to Michael Deckers.)
1688 zic now outputs a dummy transition at time 2**31 - 1 in zones
1689 whose POSIX-style TZ strings contain a '<'. This mostly works
1690 around Qt bug 53071 <https://bugreports.qt.io/browse/QTBUG-53071>.
1691 (Thanks to Zhanibek Adilbekov for reporting the Qt bug.)
1693 Changes affecting documentation and commentary
1695 tz-link.htm says why governments should give plenty of notice for
1696 time zone or DST changes, and refers to Matt Johnson's blog post.
1698 tz-link.htm mentions Tzdata for Elixir. (Thanks to Matt Johnson.)
1701 Release 2016d - 2016-04-17 22:50:29 -0700
1703 Changes affecting future timestamps
1705 America/Caracas switches from -0430 to -04 on 2016-05-01 at 02:30.
1706 (Thanks to Alexander Krivenyshev for the heads-up.)
1708 Asia/Magadan switches from +10 to +11 on 2016-04-24 at 02:00.
1709 (Thanks to Alexander Krivenyshev and Matt Johnson.)
1711 New zone Asia/Tomsk, split off from Asia/Novosibirsk. It covers
1712 Tomsk Oblast, Russia, which switches from +06 to +07 on 2016-05-29
1713 at 02:00. (Thanks to Stepan Golosunov.)
1715 Changes affecting past timestamps
1717 New zone Europe/Kirov, split off from Europe/Volgograd. It covers
1718 Kirov Oblast, Russia, which switched from +04/+05 to +03/+04 on
1719 1989-03-26 at 02:00, roughly a year after Europe/Volgograd made
1720 the same change. (Thanks to Stepan Golosunov.)
1722 Russia and nearby locations had daylight-saving transitions on
1723 1992-03-29 at 02:00 and 1992-09-27 at 03:00, instead of on
1724 1992-03-28 at 23:00 and 1992-09-26 at 23:00. (Thanks to Stepan
1727 Many corrections to historical time in Kazakhstan from 1991
1728 through 2005. (Thanks to Stepan Golosunov.) Replace Kazakhstan's
1729 invented time zone abbreviations with numeric abbreviations.
1731 Changes to commentary
1733 Mention Internet RFCs 7808 (TZDIST) and 7809 (CalDAV time zone references).
1736 Release 2016c - 2016-03-23 00:51:27 -0700
1738 Changes affecting future timestamps
1740 Azerbaijan no longer observes DST. (Thanks to Steffen Thorsen.)
1742 Chile reverts from permanent to seasonal DST. (Thanks to Juan
1743 Correa for the heads-up, and to Tim Parenti for corrections.)
1744 Guess that future transitions are August's and May's second
1745 Saturdays at 24:00 mainland time. Also, call the period from
1746 2014-09-07 through 2016-05-14 daylight saving time instead of
1747 standard time, as that seems more appropriate now.
1749 Changes affecting past timestamps
1751 Europe/Kaliningrad and Europe/Vilnius changed from +03/+04 to
1752 +02/+03 on 1989-03-26, not 1991-03-31. Europe/Volgograd changed
1753 from +04/+05 to +03/+04 on 1988-03-27, not 1989-03-26.
1754 (Thanks to Stepan Golosunov.)
1756 Changes to commentary
1758 Several updates and URLs for historical and proposed Russian changes.
1759 (Thanks to Stepan Golosunov, Matt Johnson, and Alexander Krivenyshev.)
1762 Release 2016b - 2016-03-12 17:30:14 -0800
1766 Starting with release 2016b, some data entries cause zic implementations
1767 derived from tz releases 2005j through 2015e to issue warnings like
1768 "time zone abbreviation differs from POSIX standard (+03)".
1769 These warnings should not otherwise affect zic's output and can safely be
1770 ignored on today's platforms, as the warnings refer to a restriction in
1771 POSIX.1-1988 that was removed in POSIX.1-2001. One way to suppress the
1772 warnings is to upgrade to zic derived from tz releases 2015f and later.
1774 Changes affecting future timestamps
1776 New zones Europe/Astrakhan and Europe/Ulyanovsk for Astrakhan and
1777 Ulyanovsk Oblasts, Russia, both of which will switch from +03 to +04 on
1778 2016-03-27 at 02:00 local time. They need distinct zones since their
1779 post-1970 histories disagree. New zone Asia/Barnaul for Altai Krai and
1780 Altai Republic, Russia, which will switch from +06 to +07 on the same date
1781 and local time. The Astrakhan change is already official; the others have
1782 passed the first reading in the State Duma and are extremely likely.
1783 Also, Asia/Sakhalin moves from +10 to +11 on 2016-03-27 at 02:00.
1784 (Thanks to Alexander Krivenyshev for the heads-up, and to Matt Johnson
1785 and Stepan Golosunov for followup.)
1787 As a trial of a new system that needs less information to be made up,
1788 the new zones use numeric time zone abbreviations like "+04"
1789 instead of invented abbreviations like "ASTT".
1791 Haiti will not observe DST in 2016. (Thanks to Jean Antoine via
1794 Palestine's spring-forward transition on 2016-03-26 is at 01:00, not 00:00.
1795 (Thanks to Hannah Kreitem.) Guess future transitions will be March's last
1796 Saturday at 01:00, not March's last Friday at 24:00.
1798 Changes affecting past timestamps
1800 Europe/Chisinau observed DST during 1990, and switched from +04 to
1801 +03 at 1990-05-06 02:00, instead of switching from +03 to +02.
1802 (Thanks to Stepan Golosunov.)
1804 1991 abbreviations in Europe/Samara should be SAMT/SAMST, not
1805 KUYT/KUYST. (Thanks to Stepan Golosunov.)
1809 tzselect's diagnostics and checking, and checktab.awk's checking,
1810 have been improved. (Thanks to J William Piggott.)
1812 tzcode now builds under MinGW. (Thanks to Ian Abbott and Esben Haabendal.)
1814 tzselect now tests Julian-date TZ settings more accurately.
1815 (Thanks to J William Piggott.)
1817 Changes to commentary
1819 Comments in zone tables have been improved. (Thanks to J William Piggott.)
1821 tzselect again limits its menu comments so that menus fit on a
1822 24×80 alphanumeric display.
1824 A new web page tz-how-to.html. (Thanks to Bill Seymour.)
1826 In the Theory file, the description of possible time zone abbreviations in
1827 tzdata has been cleaned up, as the old description was unclear and
1828 inconsistent. (Thanks to Alain Mouette for reporting the problem.)
1831 Release 2016a - 2016-01-26 23:28:02 -0800
1833 Changes affecting future timestamps
1835 America/Cayman will not observe daylight saving this year after all.
1836 Revert our guess that it would. (Thanks to Matt Johnson.)
1838 Asia/Chita switches from +0800 to +0900 on 2016-03-27 at 02:00.
1839 (Thanks to Alexander Krivenyshev.)
1841 Asia/Tehran now has DST predictions for the year 2038 and later,
1842 to be March 21 00:00 to September 21 00:00. This is likely better
1843 than predicting no DST, albeit off by a day every now and then.
1845 Changes affecting past and future timestamps
1847 America/Metlakatla switched from PST all year to AKST/AKDT on
1848 2015-11-01 at 02:00. (Thanks to Steffen Thorsen.)
1850 America/Santa_Isabel has been removed, and replaced with a
1851 backward compatibility link to America/Tijuana. Its contents were
1852 apparently based on a misreading of Mexican legislation.
1854 Changes affecting past timestamps
1856 Asia/Karachi's two transition times in 2002 were off by a minute.
1857 (Thanks to Matt Johnson.)
1859 Changes affecting build procedure
1861 An installer can now combine leap seconds with use of the backzone file,
1862 e.g., with 'make PACKRATDATA=backzone REDO=posix_right zones'.
1863 The old 'make posix_packrat' rule is now marked as obsolescent.
1864 (Thanks to Ian Abbott for an initial implementation.)
1866 Changes affecting documentation and commentary
1868 A new file LICENSE makes it easier to see that the code and data
1869 are mostly public-domain. (Thanks to James Knight.) The three
1870 non-public-domain files now use the current (3-clause) BSD license
1871 instead of older versions of that license.
1873 tz-link.htm mentions the BDE library (thanks to Andrew Paprocki),
1874 CCTZ (thanks to Tim Parenti), TimeJones.com, and has a new section
1875 on editing tz source files (with a mention of Sublime zoneinfo,
1876 thanks to Gilmore Davidson).
1878 The Theory and asia files now mention the 2015 book "The Global
1879 Transformation of Time, 1870-1950", and cite a couple of reviews.
1881 The America/Chicago entry now documents the informal use of US
1882 central time in Fort Pierre, South Dakota. (Thanks to Rick
1883 McDermid, Matt Johnson, and Steve Jones.)
1886 Release 2015g - 2015-10-01 00:39:51 -0700
1888 Changes affecting future timestamps
1890 Turkey's 2015 fall-back transition is scheduled for Nov. 8, not Oct. 25.
1893 Norfolk moves from +1130 to +1100 on 2015-10-04 at 02:00 local time.
1894 (Thanks to Alexander Krivenyshev.)
1896 Fiji's 2016 fall-back transition is scheduled for January 17, not 24.
1897 (Thanks to Ken Rylander.)
1899 Fort Nelson, British Columbia will not fall back on 2015-11-01. It has
1900 effectively been on MST (-0700) since it advanced its clocks on 2015-03-08.
1901 New zone America/Fort_Nelson. (Thanks to Matt Johnson.)
1903 Changes affecting past timestamps
1905 Norfolk observed DST from 1974-10-27 02:00 to 1975-03-02 02:00.
1907 Changes affecting code
1909 localtime no longer mishandles America/Anchorage after 2037.
1910 (Thanks to Bradley White for reporting the bug.)
1912 On hosts with signed 32-bit time_t, localtime no longer mishandles
1913 Pacific/Fiji after 2038-01-16 14:00 UTC.
1915 The localtime module allows the variables 'timezone', 'daylight',
1916 and 'altzone' to be in common storage shared with other modules,
1917 and declares them in case the system <time.h> does not.
1918 (Problems reported by Kees Dekker.)
1920 On platforms with tm_zone, strftime.c now assumes it is not NULL.
1921 This simplifies the code and is consistent with zdump.c.
1922 (Problem reported by Christos Zoulas.)
1924 Changes affecting documentation
1926 The tzfile man page now documents that transition times denote the
1927 starts (not the ends) of the corresponding time periods.
1928 (Ambiguity reported by Bill Seymour.)
1931 Release 2015f - 2015-08-10 18:06:56 -0700
1933 Changes affecting future timestamps
1935 North Korea switches to +0830 on 2015-08-15. (Thanks to Steffen Thorsen.)
1936 The abbreviation remains "KST". (Thanks to Robert Elz.)
1938 Uruguay no longer observes DST. (Thanks to Steffen Thorsen
1941 Changes affecting past and future timestamps
1943 Moldova starts and ends DST at 00:00 UTC, not at 01:00 UTC.
1944 (Thanks to Roman Tudos.)
1946 Changes affecting data format and code
1948 zic's '-y YEARISTYPE' option is no longer documented. The TYPE
1949 field of a Rule line should now be '-'; the old values 'even',
1950 'odd', 'uspres', 'nonpres', 'nonuspres' were already undocumented.
1951 Although the implementation has not changed, these features do not
1952 work in the default installation, they are not used in the data,
1953 and they are now considered obsolescent.
1955 zic now checks that two rules don't take effect at the same time.
1956 (Thanks to Jon Skeet and Arthur David Olson.) Constraints on
1957 simultaneity are now documented.
1959 The two characters '%z' in a zone format now stand for the UT
1960 offset, e.g., '-07' for seven hours behind UT and '+0530' for
1961 five hours and thirty minutes ahead. This better supports time
1962 zone abbreviations conforming to POSIX.1-2001 and later.
1964 Changes affecting installed data files
1966 Comments for America/Halifax and America/Glace_Bay have been improved.
1967 (Thanks to Brian Inglis.)
1969 Data entries have been simplified for Atlantic/Canary, Europe/Simferopol,
1970 Europe/Sofia, and Europe/Tallinn. This yields slightly smaller
1971 installed data files for Europe/Simferopol and Europe/Tallinn.
1972 It does not affect timestamps. (Thanks to Howard Hinnant.)
1974 Changes affecting code
1976 zdump and zic no longer warn about valid time zone abbreviations
1979 Some Visual Studio 2013 warnings have been suppressed.
1980 (Thanks to Kees Dekker.)
1982 'date' no longer sets the time of day and its -a, -d, -n and -t
1983 options have been removed. Long obsolescent, the implementation
1984 of these features had porting problems. Builders no longer need
1985 to configure HAVE_ADJTIME, HAVE_SETTIMEOFDAY, or HAVE_UTMPX_H.
1986 (Thanks to Kees Dekker for pointing out the problem.)
1988 Changes affecting documentation
1990 The Theory file mentions naming issues earlier, as these seem to be
1991 poorly publicized (thanks to Gilmore Davidson for reporting the problem).
1993 tz-link.htm mentions Time Zone Database Parser (thanks to Howard Hinnant).
1995 Mention that Herbert Samuel introduced the term "Summer Time".
1998 Release 2015e - 2015-06-13 10:56:02 -0700
2000 Changes affecting future timestamps
2002 Morocco will suspend DST from 2015-06-14 03:00 through 2015-07-19 02:00,
2003 not 06-13 and 07-18 as we had guessed. (Thanks to Milamber.)
2005 Assume Cayman Islands will observe DST starting next year, using US rules.
2006 Although it isn't guaranteed, it is the most likely.
2008 Changes affecting data format
2010 The file 'iso3166.tab' now uses UTF-8, so that its entries can better
2011 spell the names of Åland Islands, Côte d'Ivoire, and Réunion.
2013 Changes affecting code
2015 When displaying data, tzselect converts it to the current locale's
2016 encoding if the iconv command works. (Problem reported by random832.)
2018 tzselect no longer mishandles Dominica, fixing a bug introduced
2019 in Release 2014f. (Problem reported by Owen Leibman.)
2021 zic -l no longer fails when compiled with -DTZDEFAULT=\"/etc/localtime\".
2022 This fixes a bug introduced in Release 2014f.
2023 (Problem reported by Leonardo Chiquitto.)
2026 Release 2015d - 2015-04-24 08:09:46 -0700
2028 Changes affecting future timestamps
2030 Egypt will not observe DST in 2015 and will consider canceling it
2031 permanently. For now, assume no DST indefinitely.
2032 (Thanks to Ahmed Nazmy and Tim Parenti.)
2034 Changes affecting past timestamps
2036 America/Whitehorse switched from UT -09 to -08 on 1967-05-28, not
2037 1966-07-01. Also, Yukon's time zone history is documented better.
2038 (Thanks to Brian Inglis and Dennis Ferguson.)
2040 Change affecting past and future time zone abbreviations
2042 The abbreviations for Hawaii-Aleutian standard and daylight times
2043 have been changed from HAST/HADT to HST/HDT, as per US Government
2044 Printing Office style. This affects only America/Adak since 1983,
2045 as America/Honolulu was already using the new style.
2047 Changes affecting code
2049 zic has some minor performance improvements.
2052 Release 2015c - 2015-04-11 08:55:55 -0700
2054 Changes affecting future timestamps
2056 Egypt's spring-forward transition is at 24:00 on April's last Thursday,
2057 not 00:00 on April's last Friday. 2015's transition will therefore be on
2058 Thursday, April 30 at 24:00, not Friday, April 24 at 00:00. Similar fixes
2059 apply to 2026, 2037, 2043, etc. (Thanks to Steffen Thorsen.)
2061 Changes affecting past timestamps
2063 The following changes affect some pre-1991 Chile-related timestamps
2064 in America/Santiago, Antarctica/Palmer, and Pacific/Easter.
2066 The 1910 transition was January 10, not January 1.
2068 The 1918 transition was September 10, not September 1.
2070 The UT -04 time observed from 1932 to 1942 is now considered to
2071 be standard time, not year-round DST.
2073 Santiago observed DST (UT -03) from 1946-07-15 through
2074 1946-08-31, then reverted to standard time, then switched to -05
2077 Assume transitions before 1968 were at 00:00, since we have no data
2080 The spring 1988 transition was 1988-10-09, not 1988-10-02.
2081 The fall 1990 transition was 1990-03-11, not 1990-03-18.
2083 Assume no UT offset change for Pacific/Easter on 1890-01-01,
2084 and omit all transitions on Pacific/Easter from 1942 through 1946
2085 since we have no data suggesting that they existed.
2087 One more zone has been turned into a link, as it differed
2088 from an existing zone only for older timestamps. As usual,
2089 this change affects UT offsets in pre-1970 timestamps only.
2090 The zone's old contents have been moved to the 'backzone' file.
2091 The affected zone is America/Montreal.
2093 Changes affecting commentary
2095 Mention the TZUpdater tool.
2097 Mention "The Time Now". (Thanks to Brandon Ramsey.)
2100 Release 2015b - 2015-03-19 23:28:11 -0700
2102 Changes affecting future timestamps
2104 Mongolia will start observing DST again this year, from the last
2105 Saturday in March at 02:00 to the last Saturday in September at 00:00.
2106 (Thanks to Ganbold Tsagaankhuu.)
2108 Palestine will start DST on March 28, not March 27. Also,
2109 correct the fall 2014 transition from September 26 to October 24.
2110 Adjust future predictions accordingly. (Thanks to Steffen Thorsen.)
2112 Changes affecting past timestamps
2114 The 1982 zone shift in Pacific/Easter has been corrected, fixing a 2015a
2115 regression. (Thanks to Stuart Bishop for reporting the problem.)
2117 Some more zones have been turned into links, when they differed
2118 from existing zones only for older timestamps. As usual,
2119 these changes affect UT offsets in pre-1970 timestamps only.
2120 Their old contents have been moved to the 'backzone' file.
2121 The affected zones are: America/Antigua, America/Cayman,
2122 Pacific/Midway, and Pacific/Saipan.
2124 Changes affecting time zone abbreviations
2126 Correct the 1992-2010 DST abbreviation in Volgograd from "MSK" to "MSD".
2129 Changes affecting code
2131 Fix integer overflow bug in reference 'mktime' implementation.
2132 (Problem reported by Jörg Richter.)
2134 Allow -Dtime_tz=time_t compilations, and allow -Dtime_tz=... libraries
2135 to be used in the same executable as standard-library time_t functions.
2136 (Problems reported by Bradley White.)
2138 Changes affecting commentary
2140 Cite the recent Mexican decree changing Quintana Roo's time zone.
2141 (Thanks to Carlos Raúl Perasso.)
2143 Likewise for the recent Chilean decree. (Thanks to Eduardo Romero Urra.)
2145 Update info about Mars time.
2148 Release 2015a - 2015-01-29 22:35:20 -0800
2150 Changes affecting future timestamps
2152 The Mexican state of Quintana Roo, represented by America/Cancun,
2153 will shift from Central Time with DST to Eastern Time without DST
2154 on 2015-02-01 at 02:00. (Thanks to Steffen Thorsen and Gwillim Law.)
2156 Chile will not change clocks in April or thereafter; its new standard time
2157 will be its old daylight saving time. This affects America/Santiago,
2158 Pacific/Easter, and Antarctica/Palmer. (Thanks to Juan Correa.)
2160 New leap second 2015-06-30 23:59:60 UTC as per IERS Bulletin C 49.
2161 (Thanks to Tim Parenti.)
2163 Changes affecting past timestamps
2165 Iceland observed DST in 1919 and 1921, and its 1939 fallback
2166 transition was Oct. 29, not Nov. 29. Remove incorrect data from
2167 Shanks about time in Iceland between 1837 and 1908.
2169 Some more zones have been turned into links, when they differed
2170 from existing zones only for older timestamps. As usual,
2171 these changes affect UT offsets in pre-1970 timestamps only.
2172 Their old contents have been moved to the 'backzone' file.
2173 The affected zones are: Asia/Aden, Asia/Bahrain, Asia/Kuwait,
2176 Changes affecting code
2178 tzalloc now scrubs time zone abbreviations compatibly with the way
2179 that tzset always has, by replacing invalid bytes with '_' and by
2180 shortening too-long abbreviations.
2182 tzselect ports to POSIX awk implementations, no longer mishandles
2183 POSIX TZ settings when GNU awk is used, and reports POSIX TZ
2184 settings to the user. (Thanks to Stefan Kuhn.)
2186 Changes affecting build procedure
2188 'make check' now checks for links to links in the data.
2189 One such link (for Africa/Asmera) has been fixed.
2190 (Thanks to Stephen Colebourne for pointing out the problem.)
2192 Changes affecting commentary
2194 The leapseconds file commentary now mentions the expiration date.
2195 (Problem reported by Martin Burnicki.)
2197 Update Mexican Library of Congress URL.
2200 Release 2014j - 2014-11-10 17:37:11 -0800
2202 Changes affecting current and future timestamps
2204 Turks & Caicos' switch from US eastern time to UT -04 year-round
2205 did not occur on 2014-11-02 at 02:00. It's currently scheduled
2206 for 2015-11-01 at 02:00. (Thanks to Chris Walton.)
2208 Changes affecting past timestamps
2210 Many pre-1989 timestamps have been corrected for Asia/Seoul and
2211 Asia/Pyongyang, based on sources for the Korean-language Wikipedia
2212 entry for time in Korea. (Thanks to Sanghyuk Jung.) Also, no
2213 longer guess that Pyongyang mimicked Seoul time after World War II,
2214 as this is politically implausible.
2216 Some more zones have been turned into links, when they differed
2217 from existing zones only for older timestamps. As usual,
2218 these changes affect UT offsets in pre-1970 timestamps only.
2219 Their old contents have been moved to the 'backzone' file.
2220 The affected zones are: Africa/Addis_Ababa, Africa/Asmara,
2221 Africa/Dar_es_Salaam, Africa/Djibouti, Africa/Kampala,
2222 Africa/Mogadishu, Indian/Antananarivo, Indian/Comoro, and
2225 Changes affecting commentary
2227 The commentary is less enthusiastic about Shanks as a source,
2228 and is more careful to distinguish UT from UTC.
2231 Release 2014i - 2014-10-21 22:04:57 -0700
2233 Changes affecting future timestamps
2235 Pacific/Fiji will observe DST from 2014-11-02 02:00 to 2015-01-18 03:00.
2236 (Thanks to Ken Rylander for the heads-up.) Guess that future
2237 years will use a similar pattern.
2239 A new Zone Pacific/Bougainville, for the part of Papua New Guinea
2240 that plans to switch from UT +10 to +11 on 2014-12-28 at 02:00.
2241 (Thanks to Kiley Walbom for the heads-up.)
2243 Changes affecting time zone abbreviations
2245 Since Belarus is not changing its clocks even though Moscow is,
2246 the time zone abbreviation in Europe/Minsk is changing from FET
2247 to its more-traditional value MSK on 2014-10-26 at 01:00.
2248 (Thanks to Alexander Bokovoy for the heads-up about Belarus.)
2250 The new abbreviation IDT stands for the pre-1976 use of UT +08 in
2251 Indochina, to distinguish it better from ICT (+07).
2253 Changes affecting past timestamps
2255 Many timestamps have been corrected for Asia/Ho_Chi_Minh before 1976
2256 (thanks to Trần Ngọc Quân for an indirect pointer to Trần Tiến Bình's
2257 authoritative book). Asia/Ho_Chi_Minh has been added to
2258 zone1970.tab, to give tzselect users in Vietnam two choices,
2259 since north and south Vietnam disagreed after our 1970 cutoff.
2261 Asia/Phnom_Penh and Asia/Vientiane have been turned into links, as
2262 they differed from existing zones only for older timestamps. As
2263 usual, these changes affect pre-1970 timestamps only. Their old
2264 contents have been moved to the 'backzone' file.
2266 Changes affecting code
2268 The time-related library functions now set errno on failure, and
2269 some crashes in the new tzalloc-related library functions have
2270 been fixed. (Thanks to Christos Zoulas for reporting most of
2271 these problems and for suggesting fixes.)
2273 If USG_COMPAT is defined and the requested timestamp is standard time,
2274 the tz library's localtime and mktime functions now set the extern
2275 variable timezone to a value appropriate for that timestamp; and
2276 similarly for ALTZONE, daylight saving time, and the altzone variable.
2277 This change is a companion to the tzname change in 2014h, and is
2278 designed to make timezone and altzone more compatible with tzname.
2280 The tz library's functions now set errno to EOVERFLOW if they fail
2281 because the result cannot be represented. ctime and ctime_r now
2282 return NULL and set errno when a timestamp is out of range, rather
2283 than having undefined behavior.
2285 Some bugs associated with the new 2014g functions have been fixed.
2286 This includes a bug that largely incapacitated the new functions
2287 time2posix_z and posix2time_z. (Thanks to Christos Zoulas.)
2288 It also includes some uses of uninitialized variables after tzalloc.
2289 The new code uses the standard type 'ssize_t', which the Makefile
2290 now gives porting advice about.
2292 Changes affecting commentary
2294 Updated URLs for NRC Canada (thanks to Matt Johnson and Brian Inglis).
2297 Release 2014h - 2014-09-25 18:59:03 -0700
2299 Changes affecting past timestamps
2301 America/Jamaica's 1974 spring-forward transition was Jan. 6, not Apr. 28.
2303 Shanks says Asia/Novokuznetsk switched from LMT (not "NMT") on 1924-05-01,
2304 not 1920-01-06. The old entry was based on a misinterpretation of Shanks.
2306 Some more zones have been turned into links, when they differed
2307 from existing zones only for older timestamps. As usual,
2308 these changes affect UT offsets in pre-1970 timestamps only.
2309 Their old contents have been moved to the 'backzone' file.
2310 The affected zones are: Africa/Blantyre, Africa/Bujumbura,
2311 Africa/Gaborone, Africa/Harare, Africa/Kigali, Africa/Lubumbashi,
2312 Africa/Lusaka, Africa/Maseru, and Africa/Mbabane.
2314 Changes affecting code
2316 zdump -V and -v now output gmtoff= values on all platforms,
2317 not merely on platforms defining TM_GMTOFF.
2319 The tz library's localtime and mktime functions now set tzname to a value
2320 appropriate for the requested timestamp, and zdump now uses this
2321 on platforms not defining TM_ZONE, fixing a 2014g regression.
2322 (Thanks to Tim Parenti for reporting the problem.)
2324 The tz library no longer sets tzname if localtime or mktime fails.
2326 zdump -c no longer mishandles transitions near year boundaries.
2327 (Thanks to Tim Parenti for reporting the problem.)
2329 An access to uninitialized data has been fixed.
2330 (Thanks to Jörg Richter for reporting the problem.)
2332 When THREAD_SAFE is defined, the code ports to the C11 memory model.
2333 A memory leak has been fixed if ALL_STATE and THREAD_SAFE are defined
2334 and two threads race to initialize data used by gmtime-like functions.
2335 (Thanks to Andy Heninger for reporting the problems.)
2337 Changes affecting build procedure
2339 'make check' now checks better for properly-sorted data.
2341 Changes affecting documentation and commentary
2343 zdump's gmtoff=N output is now documented, and its isdst=D output
2344 is now documented to possibly output D values other than 0 or 1.
2346 zdump -c's treatment of years is now documented to use the
2347 Gregorian calendar and Universal Time without leap seconds,
2348 and its behavior at cutoff boundaries is now documented better.
2349 (Thanks to Arthur David Olson and Tim Parenti for reporting the problems.)
2351 Programs are now documented to use the proleptic Gregorian calendar.
2352 (Thanks to Alan Barrett for the suggestion.)
2354 Fractional-second GMT offsets have been documented for civil time
2355 in 19th-century Chennai, Jakarta, and New York.
2358 Release 2014g - 2014-08-28 12:31:23 -0700
2360 Changes affecting future timestamps
2362 Turks & Caicos is switching from US eastern time to UT -04
2363 year-round, modeled as a switch on 2014-11-02 at 02:00.
2364 [As noted in 2014j, this switch was later delayed.]
2366 Changes affecting past timestamps
2368 Time in Russia or the USSR before 1926 or so has been corrected by
2369 a few seconds in the following zones: Asia/Irkutsk,
2370 Asia/Krasnoyarsk, Asia/Omsk, Asia/Samarkand, Asia/Tbilisi,
2371 Asia/Vladivostok, Asia/Yakutsk, Europe/Riga, Europe/Samara. For
2372 Asia/Yekaterinburg the correction is a few minutes. (Thanks to
2373 Vladimir Karpinsky.)
2375 The Portuguese decree of 1911-05-26 took effect on 1912-01-01.
2376 This affects 1911 timestamps in Africa/Bissau, Africa/Luanda,
2377 Atlantic/Azores, and Atlantic/Madeira. Also, Lisbon's pre-1912
2378 GMT offset was -0:36:45 (rounded from -0:36:44.68), not -0:36:32.
2379 (Thanks to Stephen Colebourne for pointing to the decree.)
2381 Asia/Dhaka ended DST on 2009-12-31 at 24:00, not 23:59.
2383 A new file 'backzone' contains data which may appeal to
2384 connoisseurs of old timestamps, although it is out of scope for
2385 the tz database, is often poorly sourced, and contains some data
2386 that is known to be incorrect. The new file is not recommended
2387 for ordinary use and its entries are not installed by default.
2388 (Thanks to Lester Caine for the high-quality Jersey, Guernsey, and
2389 Isle of Man entries.)
2391 Some more zones have been turned into links, when they differed
2392 from existing zones only for older timestamps. As usual,
2393 these changes affect UT offsets in pre-1970 timestamps only.
2394 Their old contents have been moved to the 'backzone' file.
2395 The affected zones are: Africa/Bangui, Africa/Brazzaville,
2396 Africa/Douala, Africa/Kinshasa, Africa/Libreville, Africa/Luanda,
2397 Africa/Malabo, Africa/Niamey, and Africa/Porto-Novo.
2399 Changes affecting code
2401 Unless NETBSD_INSPIRED is defined to 0, the tz library now
2402 supplies functions for creating and using objects that represent
2403 timezones. The new functions are tzalloc, tzfree, localtime_rz,
2404 mktime_z, and (if STD_INSPIRED is also defined) posix2time_z and
2405 time2posix_z. They are intended for performance: for example,
2406 localtime_rz (unlike localtime_r) is trivially thread-safe without
2407 locking. (Thanks to Christos Zoulas for proposing NetBSD-inspired
2408 functions, and to Alan Barrett and Jonathan Lennox for helping to
2411 zdump now builds with the tz library unless USE_LTZ is defined to 0,
2412 This lets zdump use tz features even if the system library lacks them.
2413 To build zdump with the system library, use 'make CFLAGS=-DUSE_LTZ=0
2414 TZDOBJS=zdump.o CHECK_TIME_T_ALTERNATIVES='.
2416 zdump now uses localtime_rz if available, as it's significantly faster,
2417 and it can help zdump better diagnose invalid timezone names.
2418 Define HAVE_LOCALTIME_RZ to 0 to suppress this. HAVE_LOCALTIME_RZ
2419 defaults to 1 if NETBSD_INSPIRED && USE_LTZ. When localtime_rz is
2420 not available, zdump now uses localtime_r and tzset if available,
2421 as this is a bit cleaner and faster than plain localtime. Compile
2422 with -DHAVE_LOCALTIME_R=0 and/or -DHAVE_TZSET=0 if your system
2423 lacks these two functions.
2425 If THREAD_SAFE is defined to 1, the tz library is now thread-safe.
2426 Although not needed for tz's own applications, which are single-threaded,
2427 this supports POSIX better if the tz library is used in multithreaded apps.
2429 Some crashes have been fixed when zdump or the tz library is given
2430 invalid or outlandish input.
2432 The tz library no longer mishandles leap seconds on platforms with
2433 unsigned time_t in timezones that lack ordinary transitions after 1970.
2435 The tz code now attempts to infer TM_GMTOFF and TM_ZONE if not
2436 already defined, to make it easier to configure on common platforms.
2437 Define NO_TM_GMTOFF and NO_TM_ZONE to suppress this.
2439 Unless the new macro UNINIT_TRAP is defined to 1, the tz code now
2440 assumes that reading uninitialized memory yields garbage values
2441 but does not cause other problems such as traps.
2443 If TM_GMTOFF is defined and UNINIT_TRAP is 0, mktime is now
2444 more likely to guess right for ambiguous timestamps near
2445 transitions where tm_isdst does not change.
2447 If HAVE_STRFTIME_L is defined to 1, the tz library now defines
2448 strftime_l for compatibility with recent versions of POSIX.
2449 Only the C locale is supported, though. HAVE_STRFTIME_L defaults
2450 to 1 on recent POSIX versions, and to 0 otherwise.
2452 tzselect -c now uses a hybrid distance measure that works better
2453 in Africa. (Thanks to Alan Barrett for noting the problem.)
2455 The C source code now ports to NetBSD when GCC_DEBUG_FLAGS is used,
2456 or when time_tz is defined.
2458 When HAVE_UTMPX_H is set the 'date' command now builds on systems
2459 whose <utmpx.h> file does not define WTMPX_FILE, and when setting
2460 the date it updates the wtmpx file if _PATH_WTMPX is defined.
2461 This affects GNU/Linux and similar systems.
2463 For easier maintenance later, some C code has been simplified,
2464 some lint has been removed, and the code has been tweaked so that
2465 plain 'make' is more likely to work.
2467 The C type 'bool' is now used for boolean values, instead of 'int'.
2469 The long-obsolete LOCALE_HOME code has been removed.
2471 The long-obsolete 'gtime' function has been removed.
2473 Changes affecting build procedure
2475 'zdump' no longer links in ialloc.o, as it's not needed.
2477 'make check_time_t_alternatives' no longer assumes GNU diff.
2479 Changes affecting distribution tarballs
2481 The files checktab.awk and zoneinfo2tdf.pl are now distributed in
2482 the tzdata tarball instead of the tzcode tarball, since they help
2483 maintain the data. The NEWS and Theory files are now also
2484 distributed in the tzdata tarball, as they're relevant for data.
2485 (Thanks to Alan Barrett for pointing this out.) Also, the
2486 leapseconds.awk file is no longer distributed in the tzcode
2487 tarball, since it belongs in the tzdata tarball (where 2014f
2488 inadvertently also distributed it).
2490 Changes affecting documentation and commentary
2492 A new file CONTRIBUTING is distributed. (Thanks to Tim Parenti for
2493 suggesting a CONTRIBUTING file, and to Tony Finch and Walter Harms
2496 The man pages have been updated to use function prototypes,
2497 to document thread-safe variants like localtime_r, and to document
2498 the NetBSD-inspired functions tzalloc, tzfree, localtime_rz, and
2501 The fields in Link lines have been renamed to be more descriptive
2502 and more like the parameters of 'ln'. LINK-FROM has become TARGET,
2503 and LINK-TO has become LINK-NAME.
2505 tz-link.htm mentions the IETF's tzdist working group; Windows
2506 Runtime etc. (thanks to Matt Johnson); and HP-UX's tztab.
2508 Some broken URLs have been fixed in the commentary. (Thanks to
2511 Commentary about Philippines DST has been updated, and commentary
2512 on pre-1970 time in India has been added.
2515 Release 2014f - 2014-08-05 17:42:36 -0700
2517 Changes affecting future timestamps
2519 Russia will subtract an hour from most of its time zones on 2014-10-26
2520 at 02:00 local time. (Thanks to Alexander Krivenyshev.)
2521 There are a few exceptions: Magadan Oblast (Asia/Magadan) and Zabaykalsky
2522 Krai are subtracting two hours; conversely, Chukotka Autonomous Okrug
2523 (Asia/Anadyr), Kamchatka Krai (Asia/Kamchatka), Kemerovo Oblast
2524 (Asia/Novokuznetsk), and the Samara Oblast and the Udmurt Republic
2525 (Europe/Samara) are not changing their clocks. The changed zones are
2526 Europe/Kaliningrad, Europe/Moscow, Europe/Simferopol, Europe/Volgograd,
2527 Asia/Yekaterinburg, Asia/Omsk, Asia/Novosibirsk, Asia/Krasnoyarsk,
2528 Asia/Irkutsk, Asia/Yakutsk, Asia/Vladivostok, Asia/Khandyga,
2529 Asia/Sakhalin, and Asia/Ust-Nera; Asia/Magadan will have two hours
2530 subtracted; and Asia/Novokuznetsk's time zone abbreviation is affected,
2531 but not its UTC offset. Two zones are added: Asia/Chita (split
2532 from Asia/Yakutsk, and also with two hours subtracted) and
2533 Asia/Srednekolymsk (split from Asia/Magadan, but with only one hour
2534 subtracted). (Thanks to Tim Parenti for much of the above.)
2536 Changes affecting time zone abbreviations
2538 Australian eastern time zone abbreviations are now AEST/AEDT not EST,
2539 and similarly for the other Australian zones. That is, for eastern
2540 standard and daylight saving time the abbreviations are AEST and AEDT
2541 instead of the former EST for both; similarly, ACST/ACDT, ACWST/ACWDT,
2542 and AWST/AWDT are now used instead of the former CST, CWST, and WST.
2543 This change does not affect UT offsets, only time zone abbreviations.
2544 (Thanks to Rich Tibbett and many others.)
2546 Asia/Novokuznetsk shifts from NOVT to KRAT (remaining on UT +07)
2547 effective 2014-10-26 at 02:00 local time.
2549 The time zone abbreviation for Xinjiang Time (observed in Ürümqi)
2550 has been changed from URUT to XJT. (Thanks to Luther Ma.)
2552 Prefer MSK/MSD for Moscow time in Russia, even in other cities.
2553 Similarly, prefer EET/EEST for eastern European time in Russia.
2555 Change time zone abbreviations in (western) Samoa to use "ST" and
2556 "DT" suffixes, as this is more likely to match common practice.
2557 Prefix "W" to (western) Samoa time when its standard-time offset
2558 disagrees with that of American Samoa.
2560 America/Metlakatla now uses PST, not MeST, to abbreviate its time zone.
2562 Time zone abbreviations have been updated for Japan's two time
2563 zones used 1896-1937. JWST now stands for Western Standard
2564 Time, and JCST for Central Standard Time (formerly this was CJT).
2565 These abbreviations are now used for time in Korea, Taiwan,
2566 and Sakhalin while controlled by Japan.
2568 Changes affecting past timestamps
2570 China's five zones have been simplified to two, since the post-1970
2571 differences in the other three seem to have been imaginary. The
2572 zones Asia/Harbin, Asia/Chongqing, and Asia/Kashgar have been
2573 removed; backwards-compatibility links still work, albeit with
2574 different behaviors for timestamps before May 1980. Asia/Urumqi's
2575 1980 transition to UT +08 has been removed, so that it is now at
2576 +06 and not +08. (Thanks to Luther Ma and to Alois Treindl;
2577 Treindl sent helpful translations of two papers by Guo Qingsheng.)
2579 Some zones have been turned into links, when they differed from existing
2580 zones only for older UT offsets where data entries were likely invented.
2581 These changes affect UT offsets in pre-1970 timestamps only. This is
2582 similar to the change in release 2013e, except this time for western
2583 Africa. The affected zones are: Africa/Bamako, Africa/Banjul,
2584 Africa/Conakry, Africa/Dakar, Africa/Freetown, Africa/Lome,
2585 Africa/Nouakchott, Africa/Ouagadougou, Africa/Sao_Tome, and
2586 Atlantic/St_Helena. This also affects the backwards-compatibility
2587 link Africa/Timbuktu. (Thanks to Alan Barrett, Stephen Colebourne,
2588 Tim Parenti, and David Patte for reporting problems in earlier
2589 versions of this change.)
2591 Asia/Shanghai's pre-standard-time UT offset has been changed from
2592 8:05:57 to 8:05:43, the location of Xujiahui Observatory. Its
2593 transition to standard time has been changed from 1928 to 1901.
2595 Asia/Taipei switched to JWST on 1896-01-01, then to JST on 1937-10-01,
2596 then to CST on 1945-09-21 at 01:00, and did not observe DST in 1945.
2597 In 1946 it observed DST from 05-15 through 09-30; in 1947
2598 from 04-15 through 10-31; and in 1979 from 07-01 through 09-30.
2599 (Thanks to Yu-Cheng Chuang.)
2601 Asia/Riyadh's transition to standard time is now 1947-03-14, not 1950.
2603 Europe/Helsinki's 1942 fall-back transition was 10-04 at 01:00, not
2604 10-03 at 00:00. (Thanks to Konstantin Hyppönen.)
2606 Pacific/Pago_Pago has been changed from UT -11:30 to -11 for the
2607 period from 1911 to 1950.
2609 Pacific/Chatham has been changed to New Zealand standard time plus
2610 45 minutes for the period before 1957, reflecting a 1956 remark in
2611 the New Zealand parliament.
2613 Europe/Budapest has several pre-1946 corrections: in 1918 the transition
2614 out of DST was on 09-16, not 09-29; in 1919 it was on 11-24, not 09-15; in
2615 1945 it was on 11-01, not 11-03; in 1941 the transition to DST was 04-08
2616 not 04-06 at 02:00; and there was no DST in 1920.
2618 Africa/Accra is now assumed to have observed DST from 1920 through 1935.
2620 Time in Russia before 1927 or so has been corrected by a few seconds in
2621 the following zones: Europe/Moscow, Asia/Irkutsk, Asia/Tbilisi,
2622 Asia/Tashkent, Asia/Vladivostok, Asia/Yekaterinburg, Europe/Helsinki, and
2623 Europe/Riga. Also, Moscow's location has been changed to its Kilometer 0
2624 point. (Thanks to Vladimir Karpinsky for the Moscow changes.)
2626 Changes affecting data format
2628 A new file 'zone1970.tab' supersedes 'zone.tab' in the installed data.
2629 The new file's extended format allows multiple country codes per zone.
2630 The older file is still installed but is deprecated; its format is
2631 not changing and it will still be distributed for a while, but new
2632 applications should use the new file.
2634 The new file format simplifies maintenance of obscure locations.
2635 To test this, it adds coverage for the Crozet Islands and the
2636 Scattered Islands. (Thanks to Tobias Conradi and Antoine Leca.)
2638 The file 'iso3166.tab' is planned to switch from ASCII to UTF-8.
2639 It is still ASCII now, but commentary about the switch has been added.
2640 The new file 'zone1970.tab' already uses UTF-8.
2642 Changes affecting code
2644 'localtime', 'mktime', etc. now use much less stack space if ALL_STATE
2645 is defined. (Thanks to Elliott Hughes for reporting the problem.)
2647 'zic' no longer mishandles input when ignoring case in locales that
2648 are not compatible with English, e.g., unibyte Turkish locales when
2649 compiled with HAVE_GETTEXT.
2651 Error diagnostics of 'zic' and 'yearistype' have been reworded so that
2652 they no longer use ASCII '-' as if it were a dash.
2654 'zic' now rejects output file names that contain '.' or '..' components.
2655 (Thanks to Tim Parenti for reporting the problem.)
2657 'zic -v' now warns about output file names that do not follow
2658 POSIX rules, or that contain a digit or '.'. (Thanks to Arthur
2659 David Olson for starting the ball rolling on this.)
2661 Some lint has been removed when using GCC_DEBUG_FLAGS with GCC 4.9.0.
2663 Changes affecting build procedure
2665 'zic' no longer links in localtime.o and asctime.o, as they're not needed.
2666 (Thanks to John Cochran.)
2668 Changes affecting documentation and commentary
2670 The 'Theory' file documents legacy names, the longstanding
2671 exceptions to the POSIX-inspired file name rules.
2673 The 'zic' documentation clarifies the role of time types when
2674 interpreting dates. (Thanks to Arthur David Olson.)
2676 Documentation and commentary now prefer UTF-8 to US-ASCII,
2677 allowing the use of proper accents in foreign words and names.
2678 Code and data have not changed because of this. (Thanks to
2679 Garrett Wollman, Ian Abbott, and Guy Harris for helping to debug
2682 Non-HTML documentation and commentary now use plain-text URLs instead of
2683 HTML insertions, and are more consistent about bracketing URLs when they
2684 are not already surrounded by white space. (Thanks to suggestions by
2687 There is new commentary about Xujiahui Observatory, the five time-zone
2688 project in China from 1918 to 1949, timekeeping in Japanese-occupied
2689 Shanghai, and Tibet Time in the 1950s. The sharp-eyed can spot the
2690 warlord Jin Shuren in the data.
2692 Commentary about the coverage of each Russian zone has been standardized.
2693 (Thanks to Tim Parenti.)
2695 There is new commentary about contemporary timekeeping in Ethiopia.
2697 Obsolete comments about a 2007 proposal for DST in Kuwait has been removed.
2699 There is new commentary about time in Poland in 1919.
2701 Proper credit has been given to DST inventor George Vernon Hudson.
2703 Commentary about time in Metlakatla, AK and Resolute, NU has been
2704 improved, with a new source for the former.
2706 In zone.tab, Pacific/Easter no longer mentions Salas y Gómez, as it
2709 Commentary about permanent Antarctic bases has been updated.
2711 Several typos have been corrected. (Thanks to Tim Parenti for
2712 contributing some of these fixes.)
2714 tz-link.htm now mentions the JavaScript libraries Moment Timezone,
2715 TimezoneJS.Date, Walltime-js, and Timezone. (Thanks to a heads-up
2716 from Matt Johnson.) Also, it mentions the Go 'latlong' package.
2717 (Thanks to a heads-up from Dirkjan Ochtman.)
2719 The files usno1988, usno1989, usno1989a, usno1995, usno1997, and usno1998
2720 have been removed. These obsolescent US Naval Observatory entries were no
2721 longer helpful for maintenance. (Thanks to Tim Parenti for the suggestion.)
2724 Release 2014e - 2014-06-12 21:53:52 -0700
2726 Changes affecting near-future timestamps
2728 Egypt's 2014 Ramadan-based transitions are June 26 and July 31 at 24:00.
2729 (Thanks to Imed Chihi.) Guess that from 2015 on Egypt will temporarily
2730 switch to standard time at 24:00 the last Thursday before Ramadan, and
2731 back to DST at 00:00 the first Friday after Ramadan.
2733 Similarly, Morocco's are June 28 at 03:00 and August 2 at 02:00. (Thanks
2734 to Milamber Space Network.) Guess that from 2015 on Morocco will
2735 temporarily switch to standard time at 03:00 the last Saturday before
2736 Ramadan, and back to DST at 02:00 the first Saturday after Ramadan.
2738 Changes affecting past timestamps
2740 The abbreviation "MSM" (Moscow Midsummer Time) is now used instead of
2741 "MSD" for Moscow's double daylight time in summer 1921. Also, a typo
2742 "VLASST" has been repaired to be "VLAST" for Vladivostok summer time
2743 in 1991. (Thanks to Hank W. for reporting the problems.)
2745 Changes affecting commentary
2747 tz-link.htm now cites RFC 7265 for jCal, mentions PTP and the
2748 draft CalDAV extension, updates URLs for TSP, TZInfo, IATA, and
2749 removes stale pointers to World Time Explorer and WORLDTIME.
2752 Release 2014d - 2014-05-27 21:34:40 -0700
2754 Changes affecting code
2756 zic no longer generates files containing timestamps before the Big Bang.
2757 This works around GNOME glib bug 878
2758 <https://gitlab.gnome.org/GNOME/glib/issues/878>
2759 (Thanks to Leonardo Chiquitto for reporting the bug, and to
2760 Arthur David Olson and James Cloos for suggesting improvements to the fix.)
2762 Changes affecting documentation
2764 tz-link.htm now mentions GNOME.
2767 Release 2014c - 2014-05-13 07:44:13 -0700
2769 Changes affecting near-future timestamps
2771 Egypt observes DST starting 2014-05-15 at 24:00.
2772 (Thanks to Ahmad El-Dardiry and Gunther Vermier.)
2773 Details have not been announced, except that DST will not be observed
2774 during Ramadan. Guess that DST will stop during the same Ramadan dates as
2775 Morocco, and that Egypt's future spring and fall transitions will be the
2776 same as 2010 when it last observed DST, namely April's last Friday at
2777 00:00 to September's last Thursday at 23:00 standard time. Also, guess
2778 that Ramadan transitions will be at 00:00 standard time.
2780 Changes affecting code
2782 zic now generates transitions for minimum time values, eliminating guesswork
2783 when handling low-valued timestamps. (Thanks to Arthur David Olson.)
2785 Port to Cygwin sans glibc. (Thanks to Arthur David Olson.)
2787 Changes affecting commentary and documentation
2789 Remove now-confusing comment about Jordan. (Thanks to Oleksii Nochovnyi.)
2792 Release 2014b - 2014-03-24 21:28:50 -0700
2794 Changes affecting near-future timestamps
2796 Crimea switches to Moscow time on 2014-03-30 at 02:00 local time.
2797 (Thanks to Alexander Krivenyshev.) Move its zone.tab entry from UA to RU.
2799 New entry for Troll station, Antarctica. (Thanks to Paul-Inge Flakstad and
2800 Bengt-Inge Larsson.) This is currently an approximation; a better version
2801 will require the zic and localtime fixes mentioned below, and the plan is
2802 to wait for a while until at least the zic fixes propagate.
2804 Changes affecting code
2806 'zic' and 'localtime' no longer reject locations needing four transitions
2807 per year for the foreseeable future. (Thanks to Andrew Main (Zefram).)
2808 Also, 'zic' avoids some unlikely failures due to integer overflow.
2810 Changes affecting build procedure
2812 'make check' now detects Rule lines defined but never used.
2813 The NZAQ rules, an instance of this problem, have been removed.
2815 Changes affecting commentary and documentation
2817 Fix Tuesday/Thursday typo in description of time in Israel.
2818 (Thanks to Bert Katz via Pavel Kharitonov and Mike Frysinger.)
2820 Microsoft Windows 8.1 doesn't support tz database names. (Thanks
2821 to Donald MacQueen.) Instead, the Microsoft Windows Store app
2822 library supports them.
2824 Add comments about Johnston Island time in the 1960s.
2825 (Thanks to Lyle McElhaney.)
2827 Morocco's 2014 DST start will be as predicted.
2828 (Thanks to Sebastien Willemijns.)
2831 Release 2014a - 2014-03-07 23:30:29 -0800
2833 Changes affecting near-future timestamps
2835 Turkey begins DST on 2014-03-31, not 03-30. (Thanks to Faruk Pasin for
2836 the heads-up, and to Tim Parenti for simplifying the update.)
2838 Changes affecting past timestamps
2840 Fiji ended DST on 2014-01-19 at 02:00, not the previously-scheduled 03:00.
2841 (Thanks to Steffen Thorsen.)
2843 Ukraine switched from Moscow to Eastern European time on 1990-07-01
2844 (not 1992-01-01), and observed DST during the entire next winter.
2845 (Thanks to Vladimir in Moscow via Alois Treindl.)
2847 In 1988 Israel observed DST from 04-10 to 09-04, not 04-09 to 09-03.
2848 (Thanks to Avigdor Finkelstein.)
2850 Changes affecting code
2852 A uninitialized-storage bug in 'localtime' has been fixed.
2853 (Thanks to Logan Chien.)
2855 Changes affecting the build procedure
2857 The settings for 'make check_web' now default to Ubuntu 13.10.
2859 Changes affecting commentary and documentation
2861 The boundary of the US Pacific time zone is given more accurately.
2862 (Thanks to Alan Mintz.)
2864 Chile's 2014 DST will be as predicted. (Thanks to José Miguel Garrido.)
2866 Paraguay's 2014 DST will be as predicted. (Thanks to Carlos Raúl Perasso.)
2868 Better descriptions of countries with same time zone history as
2869 Trinidad and Tobago since 1970. (Thanks to Alan Barrett for suggestion.)
2871 Several changes affect tz-link.htm, the main web page.
2873 Mention Time.is (thanks to Even Scharning) and WX-now (thanks to
2876 Mention xCal (Internet RFC 6321) and jCal.
2878 Microsoft has some support for tz database names.
2880 CLDR data formats include both XML and JSON.
2882 Mention Maggiolo's map of solar vs standard time.
2883 (Thanks to Arthur David Olson.)
2885 Mention TZ4Net. (Thanks to Matt Johnson.)
2887 Mention the timezone-olson Haskell package.
2889 Mention zeitverschiebung.net. (Thanks to Martin Jäger.)
2891 Remove moribund links to daylight-savings-time.info and to
2892 Simple Timer + Clocks.
2894 Update two links. (Thanks to Oscar van Vlijmen.)
2896 Fix some formatting glitches, e.g., remove random newlines from
2897 abbr elements' title attributes.
2900 Release 2013i - 2013-12-17 07:25:23 -0800
2902 Changes affecting near-future timestamps:
2904 Jordan switches back to standard time at 00:00 on December 20, 2013.
2905 The 2006-2011 transition schedule is planned to resume in 2014.
2906 (Thanks to Steffen Thorsen.)
2908 Changes affecting past timestamps:
2910 In 2004, Cuba began DST on March 28, not April 4.
2911 (Thanks to Steffen Thorsen.)
2913 Changes affecting code
2915 The compile-time flag NOSOLAR has been removed, as nowadays the
2916 benefit of slightly shrinking runtime table size is outweighed by the
2917 cost of disallowing potential future updates that exceed old limits.
2919 Changes affecting documentation and commentary
2921 The files solar87, solar88, and solar89 are no longer distributed.
2922 They were a negative experiment - that is, a demonstration that
2923 tz data can represent solar time only with some difficulty and error.
2924 Their presence in the distribution caused confusion, as Riyadh
2925 civil time was generally not solar time in those years.
2927 tz-link.htm now mentions Noda Time. (Thanks to Matt Johnson.)
2930 Release 2013h - 2013-10-25 15:32:32 -0700
2932 Changes affecting current and future timestamps:
2934 Libya has switched its UT offset back to +02 without DST, instead
2935 of +01 with DST. (Thanks to Even Scharning.)
2937 Western Sahara (Africa/El_Aaiun) uses Morocco's DST rules.
2938 (Thanks to Gwillim Law.)
2940 Changes affecting future timestamps:
2942 Acre and (we guess) western Amazonas will switch from UT -04 to -05
2943 on 2013-11-10. This affects America/Rio_Branco and America/Eirunepe.
2944 (Thanks to Steffen Thorsen.)
2946 Add entries for DST transitions in Morocco in the year 2038.
2947 This avoids some year-2038 glitches introduced in 2013g.
2948 (Thanks to Yoshito Umaoka for reporting the problem.)
2950 Changes affecting API
2952 The 'tzselect' command no longer requires the 'select' command,
2953 and should now work with /bin/sh on more platforms. It also works
2954 around a bug in BusyBox awk before version 1.21.0. (Thanks to
2955 Patrick 'P. J.' McDermott and Alan Barrett.)
2957 Changes affecting code
2959 Fix localtime overflow bugs with 32-bit unsigned time_t.
2961 zdump no longer assumes sscanf returns maximal values on overflow.
2963 Changes affecting the build procedure
2965 The builder can specify which programs to use, if any, instead of
2966 'ar' and 'ranlib', and libtz.a is now built locally before being
2967 installed. (Thanks to Michael Forney.)
2969 A dependency typo in the 'zdump' rule has been fixed.
2970 (Thanks to Andrew Paprocki.)
2972 The Makefile has been simplified by assuming that 'mkdir -p' and 'cp -f'
2973 work as specified by POSIX.2-1992 or later; this is portable nowadays.
2975 'make clean' no longer removes 'leapseconds', since it's
2976 host-independent and is part of the distribution.
2978 The unused makefile macros TZCSRCS, TZDSRCS, DATESRCS have been removed.
2980 Changes affecting documentation and commentary
2982 tz-link.htm now mentions TC TIMEZONE's draft time zone service protocol
2983 (thanks to Mike Douglass) and TimezoneJS.Date (thanks to Jim Fehrle).
2985 Update URLs in tz-link page. Add URLs for Microsoft Windows, since
2986 8.1 introduces tz support. Remove URLs for Tru64 and UnixWare (no
2987 longer maintained) and for old advisories. SOFA now does C.
2989 Release 2013g - 2013-09-30 21:08:26 -0700
2991 Changes affecting current and near-future timestamps
2993 Morocco now observes DST from the last Sunday in March to the last
2994 Sunday in October, not April to September respectively. (Thanks
2995 to Steffen Thorsen.)
2997 Changes affecting 'zic'
2999 'zic' now runs on platforms that lack both hard links and symlinks.
3000 (Thanks to Theo Veenker for reporting the problem, for MinGW.)
3001 Also, fix some bugs on platforms that lack hard links but have symlinks.
3003 'zic -v' again warns that Asia/Tehran has no POSIX environment variable
3004 to predict the far future, fixing a bug introduced in 2013e.
3006 Changes affecting the build procedure
3008 The 'leapseconds' file is again put into the tzdata tarball.
3009 Also, 'leapseconds.awk', so tzdata is self-contained. (Thanks to
3010 Matt Burgess and Ian Abbott.) The timestamps of these and other
3011 dependent files in tarballs are adjusted more consistently.
3013 Changes affecting documentation and commentary
3015 The README file is now part of the data tarball as well as the code.
3016 It now states that files are public domain unless otherwise specified.
3017 (Thanks to Andrew Main (Zefram) for asking for clarifications.)
3018 Its details about the 1989 release moved to a place of honor near
3022 Release 2013f - 2013-09-24 23:37:36 -0700
3024 Changes affecting near-future timestamps
3026 Tocantins will very likely not observe DST starting this spring.
3027 (Thanks to Steffen Thorsen.)
3029 Jordan will likely stay at UT +03 indefinitely, and will not fall
3032 Palestine will fall back at 00:00, not 01:00. (Thanks to Steffen Thorsen.)
3034 Changes affecting API
3036 The types of the global variables 'timezone' and 'altzone' (if present)
3037 have been changed back to 'long'. This is required for 'timezone'
3038 by POSIX, and for 'altzone' by common practice, e.g., Solaris 11.
3039 These variables were originally 'long' in the tz code, but were
3040 mistakenly changed to 'time_t' in 1987; nobody reported the
3041 incompatibility until now. The difference matters on x32, where
3042 'long' is 32 bits and 'time_t' is 64. (Thanks to Elliott Hughes.)
3044 Changes affecting the build procedure
3046 Avoid long strings in leapseconds.awk to work around a mawk bug.
3047 (Thanks to Cyril Baurand.)
3049 Changes affecting documentation and commentary
3051 New file 'NEWS' that contains release notes like this one.
3053 Paraguay's law does not specify DST transition time; 00:00 is customary.
3054 (Thanks to Waldemar Villamayor-Venialbo.)
3056 Minor capitalization fixes.
3058 Changes affecting version-control only
3060 The experimental GitHub repository now contains annotated and
3061 signed tags for recent releases, e.g., '2013e' for Release 2013e.
3062 Releases are tagged starting with 2012e; earlier releases were
3063 done differently, and tags would either not have a simple name or
3064 not exactly match what was released.
3066 'make set-timestamps' is now simpler and a bit more portable.
3069 Release 2013e - 2013-09-19 23:50:04 -0700
3071 Changes affecting near-future timestamps
3073 This year Fiji will start DST on October 27, not October 20.
3074 (Thanks to David Wheeler for the heads-up.) For now, guess that
3075 Fiji will continue to spring forward the Sunday before the fourth
3078 Changes affecting current and future time zone abbreviations
3080 Use WIB/WITA/WIT rather than WIT/CIT/EIT for alphabetic Indonesian
3081 time zone abbreviations since 1932. (Thanks to George Ziegler,
3082 Priyadi Iman Nurcahyo, Zakaria, Jason Grimes, Martin Pitt, and
3083 Benny Lin.) This affects Asia/Dili, Asia/Jakarta, Asia/Jayapura,
3084 Asia/Makassar, and Asia/Pontianak.
3086 Use ART (UT -03, standard time), rather than WARST (also -03, but
3087 daylight saving time) for San Luis, Argentina since 2009.
3089 Changes affecting Godthåb timestamps after 2037 if version mismatch
3091 Allow POSIX-like TZ strings where the transition time's hour can
3092 range from -167 through 167, instead of the POSIX-required 0
3093 through 24. E.g., TZ='FJT-12FJST,M10.3.1/146,M1.3.4/75' for the
3094 new Fiji rules. This is a more-compact way to represent
3095 far-future timestamps for America/Godthab, America/Santiago,
3096 Antarctica/Palmer, Asia/Gaza, Asia/Hebron, Asia/Jerusalem,
3097 Pacific/Easter, and Pacific/Fiji. Other zones are unaffected by
3098 this change. (Derived from a suggestion by Arthur David Olson.)
3100 Allow POSIX-like TZ strings where daylight saving time is in
3101 effect all year. E.g., TZ='WART4WARST,J1/0,J365/25' for Western
3102 Argentina Summer Time all year. This supports a more-compact way
3103 to represent the 2013d data for America/Argentina/San_Luis.
3104 Because of the change for San Luis noted above this change does not
3105 affect the current data. (Thanks to Andrew Main (Zefram) for
3106 suggestions that improved this change.)
3108 Where these two TZ changes take effect, there is a minor extension
3109 to the tz file format in that it allows new values for the
3110 embedded TZ-format string, and the tz file format version number
3111 has therefore been increased from 2 to 3 as a precaution.
3112 Version-2-based client code should continue to work as before for
3113 all timestamps before 2038. Existing version-2-based client code
3114 (tzcode, GNU/Linux, Solaris) has been tested on version-3-format
3115 files, and typically works in practice even for timestamps after
3116 2037; the only known exception is America/Godthab.
3118 Changes affecting timestamps before 1970
3120 Pacific/Johnston is now a link to Pacific/Honolulu. This corrects
3121 some errors before 1947.
3123 Some zones have been turned into links, when they differ from existing
3124 zones only in older data entries that were likely invented or that
3125 differ only in LMT or transitions from LMT. These changes affect
3126 only timestamps before 1943. The affected zones are:
3127 Africa/Juba, America/Anguilla, America/Aruba, America/Dominica,
3128 America/Grenada, America/Guadeloupe, America/Marigot,
3129 America/Montserrat, America/St_Barthelemy, America/St_Kitts,
3130 America/St_Lucia, America/St_Thomas, America/St_Vincent,
3131 America/Tortola, and Europe/Vaduz. (Thanks to Alois Treindl for
3132 confirming that the old Europe/Vaduz zone was wrong and the new
3133 link is better for WWII-era times.)
3135 Change Kingston Mean Time from -5:07:12 to -5:07:11. This affects
3136 America/Cayman, America/Jamaica and America/Grand_Turk timestamps
3139 Change the UT offset of Bern Mean Time from 0:29:44 to 0:29:46.
3140 This affects Europe/Zurich timestamps from 1853 to 1894. (Thanks
3143 Change the date of the circa-1850 Zurich transition from 1849-09-12
3144 to 1853-07-16, overriding Shanks with data from Messerli about
3145 postal and telegraph time in Switzerland.
3147 Changes affecting time zone abbreviations before 1970
3149 For Asia/Jakarta, use BMT (not JMT) for mean time from 1923 to 1932,
3150 as Jakarta was called Batavia back then.
3152 Changes affecting API
3154 The 'zic' command now outputs a dummy transition when far-future
3155 data can't be summarized using a TZ string, and uses a 402-year
3156 window rather than a 400-year window. For the current data, this
3157 affects only the Asia/Tehran file. It does not affect any of the
3158 timestamps that this file represents, so zdump outputs the same
3159 information as before. (Thanks to Andrew Main (Zefram).)
3161 The 'date' command has a new '-r' option, which lets you specify
3162 the integer time to display, a la FreeBSD.
3164 The 'tzselect' command has two new options '-c' and '-n', which lets you
3165 select a zone based on latitude and longitude.
3167 The 'zic' command's '-v' option now warns about constructs that
3168 require the new version-3 binary file format. (Thanks to Arthur
3169 David Olson for the suggestion.)
3171 Support for floating-point time_t has been removed.
3172 It was always dicey, and POSIX no longer requires it.
3173 (Thanks to Eric Blake for suggesting to the POSIX committee to
3174 remove it, and thanks to Alan Barrett, Clive D.W. Feather, Andy
3175 Heninger, Arthur David Olson, and Alois Treindl, for reporting
3176 bugs and elucidating some of the corners of the old floating-point
3179 The signatures of 'offtime', 'timeoff', and 'gtime' have been
3180 changed back to the old practice of using 'long' to represent UT
3181 offsets. This had been inadvertently and mistakenly changed to
3182 'int_fast32_t'. (Thanks to Christos Zoulas.)
3184 The code avoids undefined behavior on integer overflow in some
3185 more places, including gmtime, localtime, mktime and zdump.
3187 Changes affecting the zdump utility
3189 zdump now outputs "UT" when referring to Universal Time, not "UTC".
3190 "UTC" does not make sense for timestamps that predate the introduction
3191 of UTC, whereas "UT", a more-generic term, does. (Thanks to Steve Allen
3192 for clarifying UT vs UTC.)
3194 Data changes affecting behavior of tzselect and similar programs
3196 Country code BQ is now called the more-common name "Caribbean Netherlands"
3197 rather than the more-official "Bonaire, St Eustatius & Saba".
3199 Remove from zone.tab the names America/Montreal, America/Shiprock,
3200 and Antarctica/South_Pole, as they are equivalent to existing
3201 same-country-code zones for post-1970 timestamps. The data entries for
3202 these names are unchanged, so the names continue to work as before.
3204 Changes affecting code internals
3206 zic -c now runs way faster on 64-bit hosts when given large numbers.
3208 zic now uses vfprintf to avoid allocating and freeing some memory.
3210 tzselect now computes the list of continents from the data,
3211 rather than have it hard-coded.
3213 Minor changes pacify GCC 4.7.3 and GCC 4.8.1.
3215 Changes affecting the build procedure
3217 The 'leapseconds' file is now generated automatically from a
3218 new file 'leap-seconds.list', which is a copy of
3219 <ftp://ftp.nist.gov/pub/time/leap-seconds.list>
3220 A new source file 'leapseconds.awk' implements this.
3221 The goal is simplification of the future maintenance of 'leapseconds'.
3223 When building the 'posix' or 'right' subdirectories, if the
3224 subdirectory would be a copy of the default subdirectory, it is
3225 now made a symbolic link if that is supported. This saves about
3226 2 MB of file system space.
3228 The links America/Shiprock and Antarctica/South_Pole have been
3229 moved to the 'backward' file. This affects only nondefault builds
3230 that omit 'backward'.
3232 Changes affecting version-control only
3234 .gitignore now ignores 'date'.
3236 Changes affecting documentation and commentary
3238 Changes to the 'tzfile' man page
3240 It now mentions that the binary file format may be extended in
3241 future versions by appending data.
3243 It now refers to the 'zdump' and 'zic' man pages.
3245 Changes to the 'zic' man page
3247 It lists conditions that elicit a warning with '-v'.
3249 It says that the behavior is unspecified when duplicate names
3250 are given, or if the source of one link is the target of another.
3252 Its examples are updated to match the latest data.
3254 The definition of white space has been clarified slightly.
3255 (Thanks to Michael Deckers.)
3257 Changes to the 'Theory' file
3259 There is a new section about the accuracy of the tz database,
3260 describing the many ways that errors can creep in, and
3261 explaining why so many of the pre-1970 timestamps are wrong or
3262 misleading (thanks to Steve Allen, Lester Caine, and Garrett
3263 Wollman for discussions that contributed to this).
3265 The 'Theory' file describes LMT better (this follows a
3266 suggestion by Guy Harris).
3268 It refers to the 2013 edition of POSIX rather than the 2004 edition.
3270 It's mentioned that excluding 'backward' should not affect the
3271 other data, and it suggests at least one zone.tab name per
3272 inhabited country (thanks to Stephen Colebourne).
3274 Some longstanding restrictions on names are documented, e.g.,
3275 'America/New_York' precludes 'America/New_York/Bronx'.
3277 It gives more reasons for the 1970 cutoff.
3279 It now mentions which time_t variants are supported, such as
3280 signed integer time_t. (Thanks to Paul Goyette for reporting
3281 typos in an experimental version of this change.)
3283 (Thanks to Philip Newton for correcting typos in these changes.)
3285 Documentation and commentary is more careful to distinguish UT in
3286 general from UTC in particular. (Thanks to Steve Allen.)
3288 Add a better source for the Zurich 1894 transition.
3289 (Thanks to Pierre-Yves Berger.)
3291 Update shapefile citations in tz-link.htm. (Thanks to Guy Harris.)
3294 Release 2013d - 2013-07-05 07:38:01 -0700
3296 Changes affecting future timestamps:
3298 Morocco's midsummer transitions this year are July 7 and August 10,
3299 not July 9 and August 8. (Thanks to Andrew Paprocki.)
3301 Israel now falls back on the last Sunday of October.
3302 (Thanks to Ephraim Silverberg.)
3304 Changes affecting past timestamps:
3306 Specify Jerusalem's location more precisely; this changes the pre-1880
3309 Changing affecting metadata only:
3311 Fix typos in the entries for country codes BQ and SX.
3313 Changes affecting code:
3315 Rework the code to fix a bug with handling Australia/Macquarie on
3316 32-bit hosts (thanks to Arthur David Olson).
3318 Port to platforms like NetBSD, where time_t can be wider than long.
3320 Add support for testing time_t types other than the system's.
3321 Run 'make check_time_t_alternatives' to try this out.
3322 Currently, the tests fail for unsigned time_t;
3323 this should get fixed at some point.
3325 Changes affecting documentation and commentary:
3327 Deemphasize the significance of national borders.
3329 Update the zdump man page.
3331 Remove obsolete NOID comment (thanks to Denis Excoffier).
3333 Update several URLs and comments in the web pages.
3335 Spelling fixes (thanks to Kevin Lyda and Jonathan Leffler).
3337 Update URL for CLDR Zone->Tzid table (thanks to Yoshito Umaoka).
3340 Release 2013c - 2013-04-19 16:17:40 -0700
3342 Changes affecting current and future timestamps:
3344 Palestine observed DST starting March 29, 2013. (Thanks to
3345 Steffen Thorsen.) From 2013 on, Gaza and Hebron both observe DST,
3346 with the predicted rules being the last Thursday in March at 24:00
3347 to the first Friday on or after September 21 at 01:00.
3349 Assume that the recent change to Paraguay's DST rules is permanent,
3350 by moving the end of DST to the 4th Sunday in March every year.
3351 (Thanks to Carlos Raúl Perasso.)
3353 Changes affecting past timestamps:
3355 Fix some historical data for Palestine to agree with that of
3356 timeanddate.com, as follows:
3358 The spring 2008 change in Gaza and Hebron was on 00:00 Mar 28, not
3361 The fall 2009 change in Gaza and Hebron on Sep 4 was at 01:00, not
3364 The spring 2010 change in Hebron was 00:00 Mar 26, not 00:01 Mar 27.
3366 The spring 2011 change in Gaza was 00:01 Apr 1, not 12:01 Apr 2.
3368 The spring 2011 change in Hebron on Apr 1 was at 00:01, not 12:01.
3370 The fall 2011 change in Hebron on Sep 30 was at 00:00, not 03:00.
3372 Fix times of habitation for Macquarie to agree with the Tasmania
3373 Parks & Wildlife Service history, which indicates that permanent
3374 habitation was 1899-1919 and 1948 on.
3376 Changing affecting metadata only:
3378 Macquarie Island is politically part of Australia, not Antarctica.
3379 (Thanks to Tobias Conradi.)
3381 Sort Macquarie more-consistently with other parts of Australia.
3382 (Thanks to Tim Parenti.)
3385 Release 2013b - 2013-03-10 22:33:40 -0700
3387 Changes affecting current and future timestamps:
3389 Haiti uses US daylight-saving rules this year, and presumably future years.
3390 This changes timestamps starting today. (Thanks to Steffen Thorsen.)
3392 Paraguay will end DST on March 24 this year.
3393 (Thanks to Steffen Thorsen.) For now, assume it's just this year.
3395 Morocco does not observe DST during Ramadan;
3396 try to predict Ramadan in Morocco as best we can.
3397 (Thanks to Erik Homoet for the heads-up.)
3399 Changes affecting commentary:
3401 Update URLs in tz-link page. Add URLs for webOS, BB10, iOS.
3402 Update URL for Solaris. Mention Internet RFC 6557.
3403 Update Internet RFCs 2445->5545, 2822->5322.
3404 Switch from FTP to HTTP for Internet RFCs.
3407 Release 2013a - 2013-02-27 09:20:35 -0800
3409 Change affecting binary data format:
3411 The zone offset at the end of version-2-format zone files is now
3412 allowed to be 24:00, as per POSIX.1-2008. (Thanks to Arthur David Olson.)
3414 Changes affecting current and future timestamps:
3416 Chile's 2013 rules, and we guess rules for 2014 and later, will be
3417 the same as 2012, namely Apr Sun>=23 03:00 UTC to Sep Sun>=2 04:00 UTC.
3418 (Thanks to Steffen Thorsen and Robert Elz.)
3420 New Zones Asia/Khandyga, Asia/Ust-Nera, Europe/Busingen.
3421 (Thanks to Tobias Conradi and Arthur David Olson.)
3423 Many changes affect historical timestamps before 1940.
3424 These were deduced from: Milne J. Civil time. Geogr J. 1899
3425 Feb;13(2):173-94 <https://www.jstor.org/stable/1774359>.
3427 Changes affecting the code:
3429 Fix zic bug that mishandled Egypt's 2010 changes (this also affected
3430 the data). (Thanks to Arthur David Olson.)
3432 Fix localtime bug when time_t is unsigned and data files were generated
3433 by a signed time_t system. (Thanks to Doug Bailey for reporting and
3434 to Arthur David Olson for fixing.)
3436 Allow the email address for bug reports to be set by the packager.
3437 The default is tz@iana.org, as before. (Thanks to Joseph S. Myers.)
3439 Update HTML checking to be compatible with Ubuntu 12.10.
3441 Check that files are a safe subset of ASCII. At some point we may
3442 relax this requirement to a safe subset of UTF-8. Without the
3443 check, some non-UTF-8 encodings were leaking into the distribution.
3447 Restore a comment about copyright notices that was inadvertently deleted.
3448 (Thanks to Arthur David Olson.)
3450 Improve the commentary about which districts observe what times
3451 in Russia. (Thanks to Oscar van Vlijmen and Arthur David Olson.)
3453 Add web page links to tz.js.
3455 Add "Run by the Monkeys" to tz-art. (Thanks to Arthur David Olson.)
3458 Release 2012j - 2012-11-12 18:34:49 -0800
3460 Libya moved to CET this weekend, but with DST planned next year.
3461 (Thanks to Even Scharning, Steffen Thorsen, and Tim Parenti.)
3463 Signatures now have the extension .asc, not .sign, as that's more
3464 standard. (Thanks to Phil Pennock.)
3466 The output of 'zdump --version', and of 'zic --version', now
3467 uses a format that is more typical for --version.
3468 (Thanks to Joseph S. Myers.)
3470 The output of 'tzselect --help', 'zdump --help', and 'zic --help'
3471 now uses tz@iana.org rather than the old elsie address.
3473 zic -v now complains about abbreviations that are less than 3
3474 or more than 6 characters, as per Posix. Formerly, it checked
3475 for abbreviations that were more than 3.
3477 'make public' no longer puts its temporary directory under /tmp,
3478 and uses the just-built zic rather than the system zic.
3480 Various fixes to documentation and commentary.
3483 Release 2012i - 2012-11-03 12:57:09 -0700
3485 Cuba switches from DST tomorrow at 01:00. (Thanks to Steffen Thorsen.)
3487 Linker flags can now be specified via LDFLAGS.
3488 AWK now defaults to 'awk', not 'nawk'.
3489 The shell in tzselect now defaults to /bin/bash, but this can
3490 be overridden by specifying KSHELL.
3491 The main web page now mentions the unofficial GitHub repository.
3492 (Thanks to Mike Frysinger.)
3494 Tarball signatures can now be built by running 'make signatures'.
3495 There are also new makefile rules 'tarballs', 'check_public', and
3496 separate makefile rules for each tarball and signature file.
3497 A few makefile rules are now more portable to strict POSIX.
3499 The main web page now lists the canonical IANA URL.
3502 Release 2012h - 2012-10-26 22:49:10 -0700
3504 Bahia no longer has DST. (Thanks to Kelley Cook.)
3506 Tocantins has DST. (Thanks to Rodrigo Severo.)
3508 Israel has new DST rules next year. (Thanks to Ephraim Silverberg.)
3510 Jordan stays on DST this winter. (Thanks to Steffen Thorsen.)
3514 More C modernization, except that at Arthur David Olson's suggestion
3515 the instances of 'register' were kept.
3518 Release 2012g - 2012-10-17 20:59:45 -0700
3520 Samoa fall 2012 and later. (Thanks to Nicholas Pereira and Robert Elz.)
3522 Palestine fall 2012. (Thanks to Steffen Thorsen.)
3526 To attack the version-number problem, this release ships the file
3527 'Makefile' (which contains the release number) in both the tzcode and
3528 the tzdata tarballs. The two Makefiles are identical, and should be
3529 identical in any matching pair of tarballs, so it shouldn't matter
3530 which order you extract the tarballs. Perhaps we can come up with a
3531 better version-number scheme at some point; this scheme does have the
3532 virtue of not adding more files.
3535 Release 2012f - 2012-09-12 23:17:03 -0700
3537 * australasia (Pacific/Fiji): Fiji DST is October 21 through January
3538 20 this year. (Thanks to Steffen Thorsen.)
3541 Release 2012e - 2012-08-02 20:44:55 -0700
3543 * australasia (Pacific/Fakaofo): Tokelau is UT +13, not +14.
3544 (Thanks to Steffen Thorsen.)
3546 * Use a single version number for both code and data.
3548 * .gitignore: New file.
3550 * Remove trailing white space.
3553 Release code2012c-data2012d - 2012-07-19 16:35:33 -0700
3555 Changes for Morocco's timestamps, which take effect in a couple of
3556 hours, along with infrastructure changes to accommodate how the tz
3557 code and data are released on IANA.
3560 Release data2012c - 2012-03-27 12:17:25 -0400
3563 Summer time changes for Morocco (to start late April 2012)
3566 Changes for 2012 for Gaza & the West Bank (Hebron) and Syria
3569 Haiti following US/Canada rules for 2012 (and we're assuming,
3570 for now anyway, for the future).
3573 Release 2012b - 2012-03-02 12:29:15 +0700
3575 There is just one change to tzcode2012b (compared with 2012a):
3576 the Makefile that was accidentally included with 2012a has been
3577 replaced with the version that should have been there, which is
3578 identical with the previous version (from tzcode2011i).
3580 There are just two changes in tzdata2012b compared with 2012a.
3582 Most significantly, summer time in Cuba has been delayed 3 weeks
3583 (now starts April 1 rather than March 11). Since Mar 11 (the old start
3584 date, as listed in 2012a) is just a little over a week away, this
3587 Less importantly, an excess tab in one of the changes in zone.tab
3588 in 2012a has been removed.
3591 Release 2012a - 2012-03-01 18:28:10 +0700
3593 The changes in tzcode2012a (compared to the previous version, 2011i)
3594 are entirely to the README and tz-art.htm and tz-link.htm files, if
3595 none of those concern you, you can ignore the code update. The changes
3596 reflect the changed addresses for the mailing list and the code and
3597 data distribution points & methods (and a link to DateTime::TimeZone::Tzfile
3598 has been added to tz-link.htm).
3600 In tzdata2012a (compared to the previous release, which was 2011n)
3601 the major changes are:
3602 Chile 2011/2012 and 2012/2013 summer time date adjustments.
3603 Falkland Islands onto permanent summer time (we're assuming for the
3604 foreseeable future, though 2012 is all we're fairly certain of.)
3605 Armenia has abolished Summer Time.
3606 Tokelau jumped the International Date Line back last December
3607 (just the same as their near neighbour, Samoa).
3608 America/Creston is a new zone for a small area of British Columbia
3609 There will be a leapsecond 2012-06-30 23:59:60 UTC.
3611 Other minor changes are:
3612 Corrections to 1918 Canadian summer time end dates.
3613 Updated URL for UK time zone history (in comments)
3614 A few typos in Le Corre's list of free French place names (comments)
3617 Release data2011n - 2011-10-30 14:57:54 +0700
3619 There are three changes of note - most urgently, Cuba (America/Havana)
3620 has extended summer time by two weeks, now to end on Nov 13, rather than
3621 the (already past) Oct 30. Second, the Pridnestrovian Moldavian Republic
3622 (Europe/Tiraspol) decided not to split from the rest of Moldova after
3623 all, and consequently that zone has been removed (again) and reinstated
3624 in the "backward" file as a link to Europe/Chisinau. And third, the
3625 end date for Fiji's summer time this summer was moved forward from the
3626 earlier planned Feb 26, to Jan 22.
3628 Apart from that, Moldova (MD) returns to a single entry in zone.tab
3629 (and the incorrect syntax that was in the 2011m version of that file
3630 is so fixed - it would have been fixed in a different way had this
3631 change not happened - that's the "missing" sccs version id).
3634 Release data2011m - 2011-10-24 21:42:16 +0700
3636 In particular, the typos in comments in the data (2011-11-17 should have
3637 been 2011-10-17 as Alan Barrett noted, and spelling of Tiraspol that
3638 Tim Parenti noted) have been fixed, and the change for Ukraine has been
3639 made in all 4 Ukrainian zones, rather than just Kiev (again, thanks to
3640 Tim Parenti, and also Denys Gavrysh)
3642 In addition, I added Europe/Tiraspol to zone.tab.
3644 This time, all the files have new version numbers... (including the files
3645 otherwise unchanged in 2011m that were changed in 2011l but didn't get new
3646 version numbers there...)
3649 Release data2011l - 2011-10-10 11:15:43 +0700
3651 There are just 2 changes that cause different generated tzdata files from
3652 zic, to Asia/Hebron and Pacific/Fiji - the possible change for Bahia, Brazil
3653 is included, but commented out. Compared with the diff I sent out last week,
3654 this version also includes attributions for the sources for the changes
3655 (in much the same format as ado used, but the html tags have not been
3656 checked, verified, or used in any way at all, so if there are errors there,
3657 please let me know.)
3660 Release data2011k - 2011-09-20 17:54:03 -0400
3665 Release data2011j - 2011-09-12 09:22:49 -0400
3667 (contemporary changes for Samoa; past changes for Kenya, Uganda, and
3668 Tanzania); there are also two spelling corrections to comments in
3669 the australasia file (with thanks to Christos Zoulas).
3672 Release 2011i - 2011-08-29 05:56:32 -0400
3677 Release data2011h - 2011-06-15 18:41:48 -0400
3679 Russia and Curaçao changes
3682 Release 2011g - 2011-04-25 09:07:22 -0400
3684 update the rules for Egypt to reflect its abandonment of DST this year
3687 Release 2011f - 2011-04-06 17:14:53 -0400
3692 Release 2011e - 2011-03-31 16:04:38 -0400
3694 Morocco, Chile, and tz-link changes
3697 Release 2011d - 2011-03-14 09:18:01 -0400
3699 changes that impact present-day timestamps in Cuba, Samoa, and Turkey
3702 Release 2011c - 2011-03-07 09:30:09 -0500
3704 These do affect current timestamps in Chile and Annette Island, Canada.
3707 Release 2011b - 2011-02-07 08:44:50 -0500
3712 Release 2011a - 2011-01-24 10:30:16 -0500
3717 Release data2010o - 2010-11-01 09:18:23 -0400
3719 change to the end of DST in Fiji in 2011
3722 Release 2010n - 2010-10-25 08:19:17 -0400
3727 Release 2010m - 2010-09-27 09:24:48 -0400
3729 Hong Kong, Vostok, and zic.c changes
3732 Release 2010l - 2010-08-16 06:57:25 -0400
3737 Release 2010k - 2010-07-26 10:42:27 -0400
3742 Release 2010j - 2010-05-10 09:07:48 -0400
3744 changes for Bahía de Banderas and for version naming
3747 Release data2010i - 2010-04-16 18:50:45 -0400
3749 the end of DST in Morocco on 2010-08-08
3752 Release data2010h - 2010-04-05 09:58:56 -0400
3757 Release data2010g - 2010-03-24 11:14:53 -0400
3762 Release 2010f - 2010-03-22 09:45:46 -0400
3767 Release data2010e - 2010-03-08 14:24:27 -0500
3769 corrects the Dhaka bug found by Danvin Ruangchan
3772 Release data2010d - 2010-03-06 07:26:01 -0500
3777 Release 2010c - 2010-03-01 09:20:58 -0500
3779 changes including KRE's suggestion for earlier initialization of
3780 "goahead" and "goback" structure elements
3783 Release code2010a - 2010-02-16 10:40:04 -0500
3788 Release data2010b - 2010-01-20 12:37:01 -0500
3793 Release data2010a - 2010-01-18 08:30:04 -0500
3798 Release data2009u - 2009-12-26 08:32:28 -0500
3800 changes to DST in Bangladesh
3803 Release 2009t - 2009-12-21 13:24:27 -0500
3808 Release data2009s - 2009-11-14 10:26:32 -0500
3810 (cosmetic) Antarctica change and the DST-in-Fiji-in-2009-and-2010 change
3813 Release 2009r - 2009-11-09 10:10:31 -0500
3815 "antarctica" and "tz-link.htm" changes
3818 Release 2009q - 2009-11-02 09:12:40 -0500
3820 with two corrections as reported by Eric Muller and Philip Newton
3823 Release data2009p - 2009-10-23 15:05:27 -0400
3825 Argentina (including San Luis) changes (with the correction from
3829 Release data2009o - 2009-10-14 16:49:38 -0400
3831 Samoa (commentary only), Pakistan, and Bangladesh changes
3834 Release data2009n - 2009-09-22 15:13:38 -0400
3836 added commentary for Argentina and a change to the end of DST in
3840 Release data2009m - 2009-09-03 10:23:43 -0400
3842 Samoa and Palestine changes
3845 Release data2009l - 2009-08-14 09:13:07 -0400
3847 Samoa (comments only) and Egypt
3850 Release 2009k - 2009-07-20 09:46:08 -0400
3855 Release data2009j - 2009-06-15 06:43:59 -0400
3857 Bangladesh change (with a short turnaround since the DST change is
3861 Release 2009i - 2009-06-08 09:21:22 -0400
3863 updating for DST in Bangladesh this year
3866 Release 2009h - 2009-05-26 09:19:14 -0400
3871 Release data2009g - 2009-04-20 16:34:07 -0400
3876 Release data2009f - 2009-04-10 11:00:52 -0400
3878 correct DST in Pakistan
3881 Release 2009e - 2009-04-06 09:08:11 -0400
3886 Release 2009d - 2009-03-23 09:38:12 -0400
3888 Morocco, Tunisia, Argentina, and American Astronomical Society changes
3891 Release data2009c - 2009-03-16 09:47:51 -0400
3893 change to the start of Cuban DST
3896 Release 2009b - 2009-02-09 11:15:22 -0500
3901 Release 2009a - 2009-01-21 10:09:39 -0500
3906 Release data2008i - 2008-10-21 12:10:25 -0400
3908 southamerica and zone.tab files, with Argentina DST rule changes and
3909 United States zone reordering and recommenting
3912 Release 2008h - 2008-10-13 07:33:56 -0400
3917 Release 2008g - 2008-10-06 09:03:18 -0400
3919 Fix a broken HTML anchor and update Brazil's DST transitions;
3920 there's also a slight reordering of information in tz-art.htm.
3923 Release data2008f - 2008-09-09 22:33:26 -0400
3928 Release 2008e - 2008-07-28 14:11:17 -0400
3930 changes by Arthur David Olson and Jesper Nørgaard Welen
3933 Release data2008d - 2008-07-07 09:51:38 -0400
3935 changes by Arthur David Olson, Paul Eggert, and Rodrigo Severo
3938 Release data2008c - 2008-05-19 17:48:03 -0400
3940 Pakistan, Morocco, and Mongolia
3943 Release data2008b - 2008-03-24 08:30:59 -0400
3945 including renaming Asia/Calcutta to Asia/Kolkata, with a backward
3949 Release 2008a - 2008-03-08 05:42:16 -0500
3954 Release 2007k - 2007-12-31 10:25:22 -0500
3956 most importantly, changes to the "southamerica" file based on
3957 Argentina's readoption of daylight saving time
3960 Release 2007j - 2007-12-03 09:51:01 -0500
3962 1. eliminate the "P" (parameter) macro;
3964 2. the "noncontroversial" changes circulated on the time zone
3965 mailing list (less the changes to "logwtmp.c");
3967 3. eliminate "too many transition" errors when "min" is used in time
3970 4. changes by Paul Eggert (including updated information for Venezuela).
3973 Release data2007i - 2007-10-30 10:28:11 -0400
3975 changes for Cuba and Syria
3978 Release 2007h - 2007-10-01 10:05:51 -0400
3980 changes by Paul Eggert, as well as an updated link to the ICU
3981 project in tz-link.htm
3984 Release 2007g - 2007-08-20 10:47:59 -0400
3986 changes by Paul Eggert
3988 The "leapseconds" file has been updated to incorporate the most
3989 recent International Earth Rotation and Reference Systems Service
3992 There's an addition to tz-art.htm regarding the television show "Medium".
3995 Release 2007f - 2007-05-07 10:46:46 -0400
3997 changes by Paul Eggert (including Haiti, Turks and Caicos, and New
4000 changes to zic.c to allow hour values greater than 24 (along with
4001 Paul's improved time value overflow checking)
4004 Release 2007e - 2007-04-02 10:11:52 -0400
4006 Syria and Honduras changes by Paul Eggert
4008 zic.c variable renaming changes by Arthur David Olson
4011 Release 2007d - 2007-03-20 08:48:30 -0400
4013 changes by Paul Eggert
4015 the elimination of white space at the ends of lines
4018 Release 2007c - 2007-02-26 09:09:37 -0500
4020 changes by Paul Eggert
4023 Release 2007b - 2007-02-12 09:34:20 -0500
4025 Paul Eggert's proposed change to the quotation handling logic in zic.c.
4027 changes to the commentary in "leapseconds" reflecting the IERS
4028 announcement that there is to be no positive leap second at the end
4032 Release 2007a - 2007-01-08 12:28:29 -0500
4034 changes by Paul Eggert
4036 Derick Rethan's Asmara change
4038 Oscar van Vlijmen's Easter Island local mean time change
4040 symbolic link changes
4043 Release 2006p - 2006-11-27 08:54:27 -0500
4045 changes by Paul Eggert
4048 Release 2006o - 2006-11-06 09:18:07 -0500
4050 changes by Paul Eggert
4053 Release 2006n - 2006-10-10 11:32:06 -0400
4055 changes by Paul Eggert
4058 Release 2006m - 2006-10-02 15:32:35 -0400
4060 changes for Uruguay, Palestine, and Egypt by Paul Eggert
4062 (minimalist) changes to zic.8 to clarify "until" information
4065 Release data2006l - 2006-09-18 12:58:11 -0400
4067 Paul's best-effort work on this coming weekend's Egypt time change
4070 Release 2006k - 2006-08-28 12:19:09 -0400
4072 changes by Paul Eggert
4075 Release 2006j - 2006-08-21 09:56:32 -0400
4077 changes by Paul Eggert
4080 Release code2006i - 2006-08-07 12:30:55 -0400
4084 Ken Pizzini's conversion script
4087 Release code2006h - 2006-07-24 09:19:37 -0400
4089 adds public domain notices to four files
4091 includes a fix for transition times being off by a second
4093 adds a new recording to the "arts" file (information courtesy Colin Bowern)
4096 Release 2006g - 2006-05-08 17:18:09 -0400
4098 northamerica changes by Paul Eggert
4101 Release 2006f - 2006-05-01 11:46:00 -0400
4103 a missing version number problem is fixed (with thanks to Bradley
4104 White for catching the problem)
4107 Release 2006d - 2006-04-17 14:33:43 -0400
4109 changes by Paul Eggert
4111 added new items to tz-arts.htm that were found by Paul
4114 Release 2006c - 2006-04-03 10:09:32 -0400
4116 two sets of data changes by Paul Eggert
4118 a fencepost error fix in zic.c
4120 changes to zic.c and the "europe" file to minimize differences
4121 between output produced by the old 32-bit zic and the new 64-bit
4125 Release 2006b - 2006-02-20 10:08:18 -0500
4126 [tz32code2006b + tz64code2006b + tzdata2006b]
4130 All SCCS IDs were bumped to "8.1" for this release.
4133 Release 2006a - 2006-01-30 08:59:31 -0500
4135 changes by Paul Eggert (in particular, Indiana time zone moves)
4137 an addition to the zic manual page to describe how special-case
4138 transitions are handled
4141 Release 2005r - 2005-12-27 09:27:13 -0500
4143 Canadian changes by Paul Eggert
4145 They also add "<pre>" directives to time zone data files and reflect
4146 changes to warning message logic in "zdump.c" (but with calls to
4147 "gettext" kept unbundled at the suggestion of Ken Pizzini).
4150 Release 2005q - 2005-12-13 09:17:09 -0500
4152 Nothing earth-shaking here:
4153 1. Electronic mail addresses have been removed.
4154 2. Casts of the return value of exit have been removed.
4155 3. Casts of the argument of is.* macros have been added.
4156 4. Indentation in one section of zic.c has been fixed.
4157 5. References to dead URLs in the data files have been dealt with.
4160 Release 2005p - 2005-12-05 10:30:53 -0500
4162 "systemv", "tz-link.htm", and "zdump.c" changes
4163 (less the casts of arguments to the is* macros)
4166 Release 2005o - 2005-11-28 10:55:26 -0500
4168 Georgia, Cuba, Nicaragua, and Jordan changes by Paul Eggert
4170 zdump.c lint fixes by Arthur David Olson
4173 Release 2005n - 2005-10-03 09:44:09 -0400
4175 changes by Paul Eggert (both the Uruguay changes and the Kyrgyzstan
4179 Release 2005m - 2005-08-29 12:15:40 -0400
4181 changes by Paul Eggert (with a small tweak to the tz-art change)
4183 a declaration of an unused variable has been removed from zdump.c
4186 Release 2005l - 2005-08-22 12:06:39 -0400
4188 changes by Paul Eggert
4190 overflow/underflow checks by Arthur David Olson, minus changes to
4191 the "Theory" file about the pending addition of 64-bit data (I grow
4192 less confident of the changes being accepted with each passing day,
4193 and the changes no longer increase the data files nine-fold--there's
4194 less than a doubling in size by my local Sun's reckoning)
4197 Release 2005k - 2005-07-14 14:14:24 -0400
4199 The "leapseconds" file has been edited to reflect the recently
4200 announced leap second at the end of 2005.
4202 I've also deleted electronic mail addresses from the files as an
4206 Release 2005j - 2005-06-13 14:34:13 -0400
4208 These reflect changes to limit the length of time zone abbreviations
4209 and the characters used in those abbreviations.
4211 There are also changes to handle POSIX-style "quoted" timezone
4212 environment variables.
4214 The changes were circulated on the time zone mailing list; the only
4215 change since then was the removal of a couple of minimum-length of
4216 abbreviation checks.
4219 Release data2005i - 2005-04-21 15:04:16 -0400
4221 changes (most importantly to Nicaragua and Haiti) by Paul Eggert
4224 Release 2005h - 2005-04-04 11:24:47 -0400
4226 changes by Paul Eggert
4228 minor changes to Makefile and zdump.c to produce more useful output
4229 when doing a "make typecheck"
4232 Release 2005g - 2005-03-14 10:11:21 -0500
4234 changes by Paul Eggert (a change to current DST rules in Uruguay and
4235 an update to a link to time zone software)
4238 Release 2005f - 2005-03-01 08:45:32 -0500
4240 data and documentation changes by Paul Eggert
4243 Release 2005e - 2005-02-10 15:59:44 -0500
4248 Release code2005d - 2005-01-31 09:21:47 -0500
4250 make zic complain about links to links if the -v flag is used
4252 have "make public" do more code checking
4254 add an include to "localtime.c" for the benefit of gcc systems
4257 Release 2005c - 2005-01-17 18:36:29 -0500
4259 get better results when mktime runs on a system where time_t is double
4261 changes to the data files (most importantly to Paraguay)
4264 Release 2005b - 2005-01-10 09:19:54 -0500
4266 Get localtime and gmtime working on systems with exotic time_t types.
4268 Update the leap second commentary in the "leapseconds" file.
4271 Release 2005a - 2005-01-01 13:13:44 -0500
4276 Release code2004i - 2004-12-14 13:42:58 -0500
4278 Deal with systems where time_t is unsigned.
4281 Release code2004h - 2004-12-07 11:40:18 -0500
4283 64-bit-time_t changes
4286 Release 2004g - 2004-11-02 09:06:01 -0500
4288 update to Cuba (taking effect this weekend)
4290 other changes by Paul Eggert
4292 correction of the spelling of Oslo
4294 changed versions of difftime.c and private.h
4297 Release code2004f - 2004-10-21 10:25:22 -0400
4299 Cope with wide-ranging tm_year values.
4302 Release 2004e - 2004-10-11 14:47:21 -0400
4304 Brazil/Argentina/Israel changes by Paul Eggert
4306 changes to tz-link.htm by Paul
4308 one small fix to Makefile
4311 Release 2004d - 2004-09-22 08:27:29 -0400
4313 Avoid overflow problems when TM_YEAR_BASE is added to an integer.
4316 Release 2004c - 2004-08-11 12:06:26 -0400
4318 asctime-related changes
4320 (variants of) some of the documentation changes suggested by Paul Eggert
4323 Release 2004b - 2004-07-19 14:33:35 -0400
4325 data changes by Paul Eggert - most importantly, updates for Argentina
4328 Release 2004a - 2004-05-27 12:00:47 -0400
4330 changes by Paul Eggert
4332 Handle DST transitions that occur at the end of a month in some
4333 years but at the start of the following month in other years.
4335 Add a copy of the correspondence that's the basis for claims about
4336 DST in the Navajo Nation.
4339 Release 2003e - 2003-12-15 09:36:47 -0500
4341 changes by Arthur David Olson (primarily code changes)
4343 changes by Paul Eggert (primarily data changes)
4345 minor changes to "Makefile" and "northamerica" (in the latter case,
4346 optimization of the "Toronto" rules)
4349 Release 2003d - 2003-10-06 09:34:44 -0400
4351 changes by Paul Eggert
4354 Release 2003c - 2003-09-16 10:47:05 -0400
4356 Fix bad returns in zic.c's inleap function.
4357 Thanks to Bradley White for catching the problem!
4360 Release 2003b - 2003-09-16 07:13:44 -0400
4362 Add a "--version" option (and documentation) to the zic and zdump commands.
4364 changes to overflow/underflow checking in zic
4366 a localtime typo fix.
4368 Update the leapseconds and tz-art.htm files.
4371 Release 2003a - 2003-03-24 09:30:54 -0500
4373 changes by Paul Eggert
4375 a few additions and modifications to the tz-art.htm file
4378 Release 2002d - 2002-10-15 13:12:42 -0400
4380 changes by Paul Eggert, less the "Britain (UK)" change in iso3166.tab
4382 There's also a new time zone quote in "tz-art.htm".
4385 Release 2002c - 2002-04-04 11:55:20 -0500
4387 changes by Paul Eggert
4389 Change zic.c to avoid creating symlinks to files that don't exist.
4392 Release 2002b - 2002-01-28 12:56:03 -0500
4394 [These change notes are for Release 2002a, which was corrupted.
4395 2002b was a corrected version of 2002a.]
4397 changes by Paul Eggert
4399 Update the "leapseconds" file to note that there'll be no leap
4400 second at the end of June, 2002.
4402 Change "zic.c" to deal with a problem in handling the "Asia/Bishkek" zone.
4404 Change to "difftime.c" to avoid sizeof problems.
4407 Release 2001d - 2001-10-09 13:31:32 -0400
4409 changes by Paul Eggert
4412 Release 2001c - 2001-06-05 13:59:55 -0400
4414 changes by Paul Eggert and Andrew Brown
4417 Release 2001b - 2001-04-05 16:44:38 -0400
4419 changes by Paul Eggert (modulo jnorgard's typo fix)
4421 tz-art.htm has been HTMLified.
4424 Release 2001a - 2001-03-13 12:57:44 -0500
4426 changes by Paul Eggert
4428 An addition to the "leapseconds" file: comments with the text of the
4429 latest IERS leap second notice.
4431 Trailing white space has been removed from data file lines, and
4432 repeated spaces in "Rule Jordan" lines in the "asia" file have been
4436 Release 2000h - 2000-12-14 15:33:38 -0500
4438 changes by Paul Eggert
4440 one typo fix in the "art" file
4442 With providence, this is the last update of the millennium.
4445 Release 2000g - 2000-10-10 11:35:22 -0400
4447 changes by Paul Eggert
4449 correction of John Mackin's name submitted by Robert Elz
4451 Garry Shandling's Daylight Saving Time joke (!?!) from the recent
4452 Emmy Awards broadcast.
4455 Release 2000f - 2000-08-10 09:31:58 -0400
4457 changes by Paul Eggert
4459 Added information in "tz-art.htm" on a Seinfeld reference to DST.
4461 Error checking and messages in the "yearistype" script have been
4465 Release 2000e - 2000-07-31 09:27:54 -0400
4467 data changes by Paul Eggert
4469 a change to the default value of the defined constant HAVE_STRERROR
4471 the addition of a Dave Barry quote on DST to the tz-arts file
4474 Release 2000d - 2000-04-20 15:43:04 -0400
4476 changes to the documentation and code of strftime for C99 conformance
4478 a bug fix for date.c
4480 These are based on (though modified from) changes by Paul Eggert.
4483 Release 2000c - 2000-03-04 10:31:43 -0500
4485 changes by Paul Eggert
4488 Release 2000b - 2000-02-21 12:16:29 -0500
4490 changes by Paul Eggert and Joseph Myers
4492 modest tweaks to the tz-art.htm and tz-link.htm files
4495 Release 2000a - 2000-01-18 09:21:26 -0500
4497 changes by Paul Eggert
4499 The two hypertext documents have also been renamed.
4502 Release code1999i-data1999j - 1999-11-15 18:43:22 -0500
4504 Paul Eggert's changes
4506 additions to the "zic" manual page and the "Arts.htm" file
4509 Release code1999h-data1999i - 1999-11-08 14:55:21 -0500
4514 Release data1999h - 1999-10-07 03:50:29 -0400
4516 changes by Paul Eggert to "europe" (most importantly, fixing
4517 Lithuania and Estonia)
4520 Release 1999g - 1999-09-28 11:06:18 -0400
4522 data changes by Paul Eggert (most importantly, the change for
4523 Lebanon that buys correctness for this coming Sunday)
4525 The "code" file contains changes to "Makefile" and "checktab.awk" to
4526 allow better checking of time zone files before they are published.
4529 Release 1999f - 1999-09-23 09:48:14 -0400
4531 changes by Arthur David Olson and Paul Eggert
4534 Release 1999e - 1999-08-17 15:20:54 -0400
4536 changes circulated by Paul Eggert, although the change to handling
4537 of DST-specifying timezone names has been commented out for now
4538 (search for "XXX" in "localtime.c" for details). These files also
4539 do not make any changes to the start of DST in Brazil.
4541 In addition to Paul's changes, there are updates to "Arts.htm" and
4545 Release 1999d - 1999-03-30 11:31:07 -0500
4547 changes by Paul Eggert
4549 The Makefile's "make public" rule has also been changed to do a test
4550 compile of each individual time zone data file (which should help
4551 avoid problems such as the one we had with Nicosia).
4554 Release 1999c - 1999-03-25 09:47:47 -0500
4556 changes by Paul Eggert, most importantly the change for Chile.
4559 Release 1999b - 1999-02-01 17:51:44 -0500
4561 changes by Paul Eggert
4563 code changes (suggested by Mani Varadarajan, mani at be.com) for
4564 correct handling of symbolic links when building using a relative directory
4566 code changes to generate correct messages for failed links
4568 updates to the URLs in Arts.htm
4571 Release 1999a - 1999-01-19 16:20:29 -0500
4573 error message internationalizations and corrections in zic.c and
4574 zdump.c (as suggested by Vladimir Michl, vladimir.michl at upol.cz,
4578 Release code1998h-data1998i - 1998-10-01 09:56:10 -0400
4580 changes for Brazil, Chile, and Germany
4582 support for use of "24:00" in the input files for the time zone compiler
4585 Release code1998g-data1998h - 1998-09-24 10:50:28 -0400
4587 changes by Paul Eggert
4589 correction to a define in the "private.h" file
4592 Release data1998g - 1998-08-11 03:28:35 -0000
4593 [tzdata1998g.tar.gz is missing!]
4595 Lithuanian change provided by mgedmin at pub.osf.it
4597 Move creation of the GMT link with Etc/GMT to "etcetera" (from
4598 "backward") to ensure that the GMT file is created even where folks
4599 don't want the "backward" links (as suggested by Paul Eggert).
4602 Release data1998f - 1998-07-20 13:50:00 -0000
4603 [tzdata1998f.tar.gz is missing!]
4605 Update the "leapseconds" file to include the newly-announced
4606 insertion at the end of 1998.
4609 Release code1998f - 1998-06-01 10:18:31 -0400
4611 addition to localtime.c by Guy Harris
4614 Release 1998e - 1998-05-28 09:56:26 -0400
4616 The Makefile is changed to produce zoneinfo-posix rather than
4617 zoneinfo/posix, and to produce zoneinfo-leaps rather than
4620 data changes by Paul Eggert
4622 changes from Guy Harris to provide asctime_r and ctime_r
4624 A usno1998 file (substantially identical to usno1997) has been added.
4627 Release 1998d - 1998-05-14 11:58:34 -0400
4629 changes to comments (in particular, elimination of references to CIA maps).
4630 "Arts.htm", "WWW.htm", "asia", and "australasia" are the only places
4631 where changes occur.
4634 Release 1998c - 1998-02-28 12:32:26 -0500
4636 changes by Paul Eggert (save the "French correction," on which I'll
4637 wait for the dust to settle)
4641 changes and additions to Arts.htm
4644 Release 1998b - 1998-01-17 14:31:51 -0500
4646 URL cleanups and additions
4649 Release 1998a - 1998-01-13 12:37:35 -0500
4651 changes by Paul Eggert
4654 Release code1997i-data1997k - 1997-12-29 09:53:41 -0500
4656 changes by Paul Eggert, with minor modifications from Arthur David
4657 Olson to make the files more browser friendly
4660 Release code1997h-data1997j - 1997-12-18 17:47:35 -0500
4662 minor changes to put "TZif" at the start of each timezone information file
4664 a rule has also been added to the Makefile so you can
4666 to just recompile the zone information files (rather than doing a
4667 full "make install" with its other effects).
4670 Release data1997i - 1997-10-07 08:45:38 -0400
4672 changes to Africa by Paul Eggert
4675 Release code1997g-data1997h - 1997-09-04 16:56:54 -0400
4677 corrections for Uruguay (and other locations)
4679 Arthur David Olson's simple-minded fix allowing mktime to both
4680 correctly handle leap seconds and correctly handle tm_sec values
4681 upon which arithmetic has been performed.
4684 Release code1997f-data1997g - 1997-07-19 13:15:02 -0400
4686 Paul Eggert's updates
4688 a small change to a function prototype;
4690 "Music" has been renamed "Arts.htm", HTMLified, and augmented to
4691 include information on Around the World in Eighty Days.
4694 Release code1997e-data1997f - 1997-05-03 18:52:34 -0400
4696 fixes to zic's error handling
4698 changes inspired by the item circulated on Slovenia
4700 The description of Web resources has been HTMLified for browsing
4703 A new piece of tz-related music has been added to the "Music" file.
4706 Release code1997d-data1997e - 1997-03-29 12:48:52 -0500
4708 Paul Eggert's latest suggestions
4711 Release code1997c-data1997d - 1997-03-07 20:37:54 -0500
4713 changes to "zic.c" to correct performance of the "-s" option
4715 a new file "usno1997"
4718 Release data1997c - 1997-03-04 09:58:18 -0500
4723 Release 1997b - 1997-02-27 18:34:19 -0500
4725 The data file incorporates the 1997 leap second.
4727 The code file incorporates Arthur David Olson's take on the
4728 zic/multiprocessor/directory-creation situation.
4731 Release 1997a - 1997-01-21 09:11:10 -0500
4733 Paul Eggert's Antarctica (and other changes)
4735 Arthur David Olson finessed the "getopt" issue by checking against
4736 both -1 and EOF (regardless of POSIX, SunOS 4.1.1's manual says -1
4737 is returned while SunOS 5.5's manual says EOF is returned).
4740 Release code1996o-data1996n - 1996-12-27 21:42:05 -0500
4742 Paul Eggert's latest changes
4745 Release code1996n - 1996-12-16 09:42:02 -0500
4747 link snapping fix from Bruce Evans (via Garrett Wollman)
4750 Release data1996m - 1996-11-24 02:37:34 -0000
4751 [tzdata1996m.tar.gz is missing!]
4753 Paul Eggert's batch of changes
4756 Release code1996m-data1996l - 1996-11-05 14:00:12 -0500
4758 No functional changes here; the files have simply been changed to
4759 make more use of ISO style dates in comments. The names of the above
4760 files now include the year in full.
4763 Release code96l - 1996-09-08 17:12:20 -0400
4765 tzcode96k was missing a couple of pieces.
4768 Release 96k - 1996-09-08 16:06:22 -0400
4770 the latest round of changes from Paul Eggert
4772 the recent Year 2000 material
4775 Release code96j - 1996-07-30 13:18:53 -0400
4777 Set sp->typecnt as suggested by Timothy Patrick Murphy.
4780 Release code96i - 1996-07-27 20:11:35 -0400
4782 Paul's suggested patch for strftime %V week numbers
4785 Release data96i - 1996-07-01 18:13:04 -0400
4787 "northamerica" and "europe" changes by Paul Eggert
4790 Release code96h - 1996-06-05 08:02:21 -0400
4792 fix for handling transitions specified in Universal Time
4794 Some "public domain" notices have also been added.
4797 Release code96g - 1996-05-16 14:00:26 -0400
4799 fix for the simultaneous-DST-and-zone-change challenge
4802 Release data96h - 1996-05-09 17:40:51 -0400
4804 changes by Paul Eggert
4807 Release code96f-data96g - 1996-05-03 03:09:59 -0000
4808 [tzcode96f.tar.gz + tzdata96g.tar.gz are both missing!]
4810 The changes get us some of the way to fixing the problems noted in Paul
4811 Eggert's letter yesterday (in addition to a few others). The approach
4812 has been to make zic a bit smarter about figuring out what time zone
4813 abbreviations apply just after the time specified in the "UNTIL" part
4814 of a zone line. Putting the smarts in zic means avoiding having
4815 transition times show up in both "Zone" lines and "Rule" lines, which
4816 in turn avoids multiple transition time entries in time zone files.
4817 (This also makes the zic input files such as "europe" a bit shorter and
4818 should ease maintenance.)
4821 Release data96f - 1996-04-19 19:20:03 -0000
4822 [tzdata96f.tar.gz is missing!]
4824 The only changes are to the "northamerica" file; the time zone
4825 abbreviation for Denver is corrected to MST (and MDT), and the
4826 comments for Mexico have been updated.
4829 Release data96e - 1996-03-19 17:37:26 -0500
4831 Proposals by Paul Eggert, in particular the Portugal change that
4832 comes into play at the end of this month.
4835 Release data96d - 1996-03-18 20:49:39 -0500
4840 Release code96e - 1996-02-29 15:43:27 -0000
4841 [tzcode96e.tar.gz is missing!]
4843 internationalization changes and the fix to the documentation for strftime
4846 Release code96d-data96c - 1996-02-12 11:05:27 -0500
4848 The "code" file simply updates Bob Kridle's electronic address.
4850 The "data" file updates rules for Mexico.
4853 Release data96b - 1996-01-27 15:44:42 -0500
4858 Release code96c - 1996-01-16 16:58:15 -0500
4860 leap-year streamlining and binary-search changes
4865 Release code96b - 1996-01-10 20:42:39 -0500
4867 fixes and enhancements from Paul Eggert, including code that
4868 emulates the behavior of recent versions of the SunOS "date"
4872 Release 96a - 1996-01-06 09:08:24 -0500
4876 fixes to strftime.c for correct ISO 8601 week number generation,
4877 plus support for two new formats ('G' and 'g') to give ISO 8601 year
4878 numbers (which are not necessarily the same as calendar year numbers)
4881 Release code95i-data95m - 1995-12-21 12:46:47 -0500
4883 The latest revisions from Paul Eggert are included, the usno1995
4884 file has been updated, and a new file ("WWW") covering useful URLs
4888 Release code95h-data95l - 1995-12-19 18:10:12 -0500
4890 A simplification of a macro definition, a change to data for Sudan,
4891 and (for last minute shoppers) notes in the "Music" file on the CD
4895 Release code95g-data95k - 1995-10-30 10:32:47 -0500
4897 (slightly reformatted) 8-bit-clean proposed patch
4899 minor patch: US/Eastern -> America/New_York
4901 snapshot of the USNO's latest data ("usno1995")
4903 some other minor cleanups
4906 Release code95f-data95j - 1995-10-28 21:01:34 -0000
4907 [tzcode95f.tar.gz + tzdata95j.tar.gz are both missing!]
4911 support for 64-bit time_t's
4913 optimization in localtime.c
4916 Release code95e - 1995-10-13 13:23:57 -0400
4918 the mktime change to scan from future to past when trying to find time zone
4922 Release data95i - 1995-09-26 10:43:26 -0400
4924 For Canada/Central, guess that the Sun customer's "one week too
4925 early" was just a approximation, and the true error is one month
4926 too early. This is consistent with the rest of Canada.
4929 Release data95h - 1995-09-21 11:26:48 -0400
4931 latest changes from Paul Eggert
4934 Release code95d - 1995-09-14 11:14:45 -0400
4936 the addition of a "Music" file, which documents four recorded
4937 versions of the tune "Save That Time".
4940 Release data95g - 1995-09-01 17:21:36 -0400
4942 "yearistype" correction
4945 Release data95f - 1995-08-28 20:46:56 -0400
4947 Paul Eggert's change to the australasia file
4950 Release data95e - 1995-07-08 18:02:34 -0400
4952 The only change is a leap second at the end of this year.
4953 Thanks to Bradley White for forwarding news on the leap second.
4956 Release data95d - 1995-07-03 13:26:22 -0400
4958 Paul Eggert's changes
4961 Release data95c - 1995-07-02 19:19:28 -0400
4963 changes to "asia", "backward", "europe", and "southamerica"
4964 (read: northamericacentrics need not apply)
4967 Release code95c - 1995-03-13 14:00:46 -0500
4969 one-line fix for sign extension problems in detzcode
4972 Release 95b - 1995-03-04 11:22:38 -0500
4974 Minor changes in both:
4976 The "code" file contains a workaround for the lack of "unistd.h" in
4977 Microsoft C++ version 7.
4979 The "data" file contains a fixed "Link" for America/Shiprock.
4982 Release 94h - 1994-12-10 12:51:14 -0500
4986 * incorporate the changes to "zdump" and "date" to make changes to
4987 the "TZ" environment variable permanent;
4989 * incorporate the table changes by Paul Eggert;
4991 * include (and document) support for universal time specifications in
4992 data files - but do not (yet) include use of this feature in the
4995 Think of this as "TZ Classic" - the software has been set up not to break if
4996 universal time shows up in its input, and data entries have been
4997 left as is so as not to break existing implementations.
5000 Release data94f - 1994-08-20 12:56:09 -0400
5002 (with thanks!) the latest data updates from Paul Eggert
5005 Release data94e - 1994-06-04 13:13:53 -0400
5010 Release code94g - 1994-05-05 12:14:07 -0400
5012 fix missing "optind.c" and a reference to it in the Makefile
5015 Release code94f - 1994-05-05 13:00:33 -0000
5016 [tzcode94f.tar.gz is missing!]
5018 changes to avoid overflow in difftime, as well as changes to cope
5019 with the 52/53 challenge in strftime
5022 Release code94e - 1994-03-30 23:32:59 -0500
5024 change for the benefit of PCTS
5027 Release 94d - 1994-02-24 15:42:25 -0500
5029 Avoid clashes with POSIX semantics for zones such as GMT+4.
5031 Some other very minor housekeeping is also present.
5034 Release code94c - 1994-02-10 08:52:40 -0500
5036 Fix bug where mkdirs was broken unless you compile with
5037 -fwritable-strings (which is generally losing to do).
5040 Release 94b - 1994-02-07 10:04:33 -0500
5042 work by Paul Eggert who notes:
5044 I found another book of time zone histories by E W Whitman; it's not
5045 as extensive as Shanks but has a few goodies of its own. I used it
5046 to update the tables. I also fixed some more as a result of
5047 correspondence with Adam David and Peter Ilieve, and move some stray
5048 links from 'europe' to 'backward'. I corrected some scanning errors
5051 As far as the code goes, I fixed zic to allow years in the range
5052 INT_MIN to INT_MAX; this fixed a few boundary conditions around 1900.
5053 And I cleaned up the zic documentation a little bit.
5056 Release data94a - 1994-02-03 08:58:54 -0500
5058 It simply incorporates the recently announced leap second into the
5062 Release 93g - 1993-11-22 17:28:27 -0500
5064 Paul Eggert has provided a good deal of historic information (based
5065 on Shanks), and there are some code changes to deal with the buglets
5066 that crawled out in dealing with the new information.
5069 Release 93f - 1993-10-15 12:27:46 -0400
5071 Paul Eggert's changes
5074 Release 93e - 1993-09-05 21:21:44 -0400
5076 This has updated data for Israel, England, and Kwajalein. There's
5077 also an update to "zdump" to cope with Kwajalein's 24-hour jump.
5078 Thanks to Paul Eggert and Peter Ilieve for the changes.
5081 Release 93d - 1993-06-17 23:34:17 -0400
5083 new fix and new data on Israel
5086 Release 93c - 1993-06-06 19:31:55 -0400
5091 Release 93b - 1993-02-02 14:53:58 -0500
5093 updated "leapseconds" file
5096 Release 93 - 1993-01-08 07:01:06 -0500
5098 At kre's suggestion, the package has been split in two - a code piece
5099 (which also includes documentation) that's only of use to folks who
5100 want to recompile things and a data piece useful to anyone who can
5103 The new version has a few changes to the data files, a few
5104 portability changes, and an off-by-one fix (with thanks to
5105 Tom Karzes at deshaw.com for providing a description and a
5109 Release 92c - 1992-11-21 17:35:36 -0000
5110 [tz92c.tar.Z is missing!]
5112 The fallout from the latest round of DST transitions.
5114 There are changes for Portugal, Saskatchewan, and "Pacific-New";
5115 there's also a change to "zic.c" that makes it portable to more systems.
5118 Release 92 - 1992-04-25 18:17:03 -0000
5119 [tz92.tar.Z is missing!]
5121 By popular demand (well, at any rate, following a request by kre at munnari)
5124 The 1989 update of the time zone package featured:
5126 * POSIXization (including interpretation of POSIX-style TZ environment
5127 variables, provided by Guy Harris),
5128 * ANSIfication (including versions of "mktime" and "difftime"),
5129 * SVIDulation (an "altzone" variable)
5130 * MACHination (the "gtime" function)
5131 * corrections to some time zone data (including corrections to the rules
5132 for Great Britain and New Zealand)
5133 * reference data from the United States Naval Observatory for folks who
5134 want to do additional time zones
5135 * and the 1989 data for Saudi Arabia.
5137 (Since this code will be treated as "part of the implementation" in some
5138 places and as "part of the application" in others, there's no good way to
5139 name functions, such as timegm, that are not part of the proposed ANSI C
5140 standard; such functions have kept their old, underscore-free names in this
5143 And the "dysize" function has disappeared; it was present to allow
5144 compilation of the "date" command on old BSD systems, and a version of "date"
5145 is now provided in the package. The "date" command is not created when you
5146 "make all" since it may lack options provided by the version distributed with
5147 your operating system, or may not interact with the system in the same way
5148 the native version does.
5150 Since POSIX frowns on correct leap second handling, the default behavior of
5151 the "zic" command (in the absence of a "-L" option) has been changed to omit
5152 leap second information from its output files.
5158 This file contains copies of the part of each release announcement
5159 that talks about the changes in that release. The text has been
5160 adapted and reformatted for the purposes of this file.
5162 Traditionally a release R consists of a pair of tarball files,
5163 tzcodeR.tar.gz and tzdataR.tar.gz. However, some releases (e.g.,
5164 code2010a, data2012c) consist of just one or the other tarball, and a
5165 few (e.g., code2012c-data2012d) have tarballs with mixed version
5166 numbers. Recent releases also come in an experimental format
5167 consisting of a single tarball tzdb-R.tar.lz with extra data.
5169 Release timestamps are taken from the release's commit (for newer,
5170 Git-based releases), from the newest file in the tarball (for older
5171 releases, where this info is available) or from the email announcing
5172 the release (if all else fails; these are marked with a time zone
5173 abbreviation of -0000 and an "is missing!" comment).
5175 Earlier versions of the code and data were not announced on the tz
5176 list and are not summarized here.
5178 This file is in the public domain.