1 News for the tz database
3 Release 2018i - 2018-12-30 11:05:43 -0800
6 São Tomé and Príncipe switches from +01 to +00 on 2019-01-01.
8 Changes to future timestamps
10 Due to a change in government, São Tomé and Príncipe switches back
11 from +01 to +00 on 2019-01-01 at 02:00. (Thanks to Vadim
12 Nasardinov and Michael Deckers.)
15 Release 2018h - 2018-12-23 17:59:32 -0800
18 Qyzylorda, Kazakhstan moved from +06 to +05 on 2018-12-21.
19 New zone Asia/Qostanay because Qostanay, Kazakhstan didn't move.
20 Metlakatla, Alaska observes PST this winter only.
21 Guess Morocco will continue to adjust clocks around Ramadan.
22 Add predictions for Iran from 2038 through 2090.
24 Changes to future timestamps
26 Guess that Morocco will continue to fall back just before and
27 spring forward just after Ramadan, the practice since 2012.
28 (Thanks to Maamar Abdelkader.) This means Morocco will observe
29 negative DST during Ramadan in main and vanguard formats, and in
30 rearguard format it stays in the +00 timezone and observes
31 ordinary DST in all months other than Ramadan. As before, extend
32 this guesswork to the year 2037. As a consequence, Morocco is
33 scheduled to observe three DST transitions in some Gregorian years
34 (e.g., 2033) due to the mismatch between the Gregorian and Islamic
37 The table of exact transitions for Iranian DST has been extended.
38 It formerly cut off before the year 2038 in a nod to 32-bit time_t.
39 It now cuts off before 2091 as there is doubt about how the Persian
40 calendar will treat 2091. This change predicts DST transitions in
41 2038-9, 2042-3, and 2046-7 to occur one day later than previously
42 predicted. As before, post-cutoff transitions are approximated.
44 Changes to past and future timestamps
46 Qyzylorda (aka Kyzylorda) oblast in Kazakhstan moved from +06 to
47 +05 on 2018-12-21. This is a zone split as Qostanay (aka
48 Kostanay) did not switch, so create a zone Asia/Qostanay.
50 Metlakatla moved from Alaska to Pacific standard time on 2018-11-04.
51 It did not change clocks that day and remains on -08 this winter.
52 (Thanks to Ryan Stanley.) It will revert to the usual Alaska
53 rules next spring, so this change affects only timestamps
54 from 2018-11-04 through 2019-03-10.
56 Change to past timestamps
58 Kwajalein's 1993-08-20 transition from -12 to +12 was at 24:00,
59 not 00:00. I transcribed the time incorrectly from Shanks.
60 (Thanks to Phake Nick.)
62 Nauru's 1979 transition was on 02-10 at 02:00, not 05-01 at 00:00.
63 (Thanks to Phake Nick.)
65 Guam observed DST irregularly from 1959 through 1977.
66 (Thanks to Phake Nick.)
68 Hong Kong observed DST in 1941 starting 06-15 (not 04-01), then on
69 10-01 changed standard time to +08:30 (not +08). Its transition
70 back to +08 after WWII was on 1945-09-15, not the previous day.
71 Its 1904-10-30 change took effect at 01:00 +08 (not 00:00 LMT).
72 (Thanks to Phake Nick, Steve Allen, and Joseph Myers.) Also,
73 its 1952 fallback was on 11-02 (not 10-25).
75 This release contains many changes to timestamps before 1946 due
76 to Japanese possession or occupation of Pacific/Chuuk,
77 Pacific/Guam, Pacific/Kosrae, Pacific/Kwajalein, Pacific/Majuro,
78 Pacific/Nauru, Pacific/Palau, and Pacific/Pohnpei.
79 (Thanks to Phake Nick.)
81 Assume that the Spanish East Indies was like the Philippines and
82 observed American time until the end of 1844. This affects
83 Pacific/Chuuk, Pacific/Kosrae, Pacific/Palau, and Pacific/Pohnpei.
85 Changes to past tm_isdst flags
87 For the recent Morocco change, the tm_isdst flag should be 1 from
88 2018-10-27 00:00 to 2018-10-28 03:00. (Thanks to Michael Deckers.)
89 Give a URL to the official decree. (Thanks to Matt Johnson.)
92 Release 2018g - 2018-10-26 22:22:45 -0700
95 Morocco switches to permanent +01 on 2018-10-28.
97 Changes to future timestamps
99 Morocco switches from +00/+01 to permanent +01 effective 2018-10-28,
100 so its clocks will not fall back as previously scheduled.
101 (Thanks to Mohamed Essedik Najd and Brian Inglis.)
105 When generating TZif files with leap seconds, zic no longer uses a
106 format that trips up older 32-bit clients, fixing a bug introduced
107 in 2018f. (Reported by Daniel Fischer.) Also, the zic workaround
108 for QTBUG-53071 now also works for TZif files with leap seconds.
110 The translator to rearguard format now rewrites the line
111 "Rule Japan 1948 1951 - Sep Sat>=8 25:00 0 S" to
112 "Rule Japan 1948 1951 - Sep Sun>=9 1:00 0 S".
113 This caters to zic before 2007 and to Oracle TZUpdater 2.2.0
114 and earlier. (Reported by Christos Zoulas.)
116 Changes to past time zone abbreviations
118 Change HDT to HWT/HPT for WWII-era abbreviations in Hawaii.
119 This reverts to 2011h, as the abbreviation change in 2011i was
122 Changes to documentation
124 tzfile.5 has new sections on interoperability issues.
127 Release 2018f - 2018-10-18 00:14:18 -0700
130 Volgograd moves from +03 to +04 on 2018-10-28.
131 Fiji ends DST 2019-01-13, not 2019-01-20.
132 Most of Chile changes DST dates, effective 2019-04-06.
134 Changes to future timestamps
136 Volgograd moves from +03 to +04 on 2018-10-28 at 02:00.
137 (Thanks to Alexander Fetisov and Stepan Golosunov.)
139 Fiji ends DST 2019-01-13 instead of the 2019-01-20 previously
140 predicted. (Thanks to Raymond Kumar.) Adjust future predictions
143 Most of Chile will end DST on the first Saturday in April at 24:00 mainland
144 time, and resume DST on the first Saturday in September at 24:00 mainland
145 time. The changes are effective from 2019-04-06, and do not affect the
146 Magallanes region modeled by America/Punta_Arenas. (Thanks to Juan Correa
147 and Tim Parenti.) Adjust future predictions accordingly.
149 Changes to past timestamps
151 The 2018-05-05 North Korea 30-minute time zone change took place
152 at 23:30 the previous day, not at 00:00 that day.
154 China's 1988 spring-forward transition was on April 17, not
155 April 10. Its DST transitions in 1986/91 were at 02:00, not 00:00.
158 Fix several issues for Macau before 1992. Macau's pre-1904 LMT
159 was off by 10 s. Macau switched to +08 in 1904 not 1912, and
160 temporarily switched to +09/+10 during World War II. Macau
161 observed DST in 1942/79, not 1961/80, and there were several
162 errors for transition times and dates. (Thanks to P Chan.)
164 The 1948-1951 fallback transitions in Japan were at 25:00 on
165 September's second Saturday, not at 24:00. (Thanks to Phake Nick.)
166 zic turns this into 01:00 on the day after September's second
167 Saturday, which is the best that POSIX or C platforms can do.
169 Incorporate 1940-1949 Asia/Shanghai DST transitions from a 2014
170 paper by Li Yu, replacing more-questionable data from Shanks.
172 Changes to time zone abbreviations
174 Use "PST" and "PDT" for Philippine time. (Thanks to Paul Goyette.)
178 zic now always generates TZif files where time type 0 is used for
179 timestamps before the first transition. This simplifies the
180 reading of TZif files and should not affect behavior of existing
181 TZif readers because the same set of time types is used; only
182 their internal indexes may have changed. This affects only the
183 legacy zones EST5EDT, CST6CDT, MST7MDT, PST8PDT, CET, MET, and
184 EET, which previously used nonzero types for these timestamps.
186 Because of the type 0 change, zic no longer outputs a dummy
187 transition at time -2**59 (before the Big Bang), as clients should
188 no longer need this to handle historical timestamps correctly.
189 This reverts a change introduced in 2013d and shrinks most TZif
190 files by a few bytes.
192 zic now supports negative time-of-day in Rule and Leap lines, e.g.,
193 "Rule X min max - Apr lastSun -6:00 1:00 -" means the transition
194 occurs at 18:00 on the Saturday before the last Sunday in April.
195 This behavior was documented in 2018a but the code did not
196 entirely match the documentation.
198 localtime.c no longer requires at least one time type in TZif
199 files that lack transitions or have a POSIX-style TZ string. This
200 future-proofs the code against possible future extensions to the
201 format that would allow TZif files with POSIX-style TZ strings and
202 without transitions or time types.
204 A read-access subscript error in localtime.c has been fixed.
205 It could occur only in TZif files with timecnt == 0, something that
206 does not happen in practice now but could happen in future versions.
208 localtime.c no longer ignores TZif POSIX-style TZ strings that
209 specify only standard time. Instead, these TZ strings now
210 override the default time type for timestamps after the last
211 transition (or for all timestamps if there are no transitions),
212 just as DST strings specifying DST have always done.
214 leapseconds.awk now outputs "#updated" and "#expires" comments,
215 and supports leap seconds at the ends of months other than June
216 and December. (Inspired by suggestions from Chris Woodbury.)
218 Changes to documentation
220 New restrictions: A Rule name must start with a character that
221 is neither an ASCII digit nor "-" nor "+", and an unquoted name
222 should not use characters in the set "!$%&'()*,/:;<=>?@[\]^`{|}~".
223 The latter restriction makes room for future extensions (a
224 possibility noted by Tom Lane).
226 tzfile.5 now documents what time types apply before the first and
227 after the last transition, if any.
229 Documentation now uses the spelling "timezone" for a TZ setting
230 that determines timestamp history, and "time zone" for a
231 geographic region currently sharing the same standard time.
233 The name "TZif" is now used for the tz binary data format.
235 tz-link.htm now mentions the A0 TimeZone Migration utilities.
236 (Thanks to Aldrin Martoq for the link.)
238 Changes to build procedure
240 New 'make' target 'rearguard_tarballs' to build the rearguard
241 tarball only. This is a convenience on platforms that lack lzip
242 if you want to build the rearguard tarball. (Problem reported by
245 tzdata.zi is now more stable from release to release. (Problem
246 noted by Tom Lane.) It is also a bit shorter.
248 tzdata.zi now can contain comment lines documenting configuration
249 information, such as which data format was selected, which input
250 files were used, and how leap seconds are treated. (Problems
251 noted by Lester Caine and Brian Inglis.) If the Makefile defaults
252 are used these comment lines are absent, for backward
253 compatibility. A redistributor intending to alter its copy of the
254 files should also append "-LABEL" to the 'version' file's first
255 line, where "LABEL" identifies the redistributor's change.
258 Release 2018e - 2018-05-01 23:42:51 -0700
262 North Korea switches back to +09 on 2018-05-05.
263 The main format uses negative DST again, for Ireland etc.
264 'make tarballs' now also builds a rearguard tarball.
265 New 's' and 'd' suffixes in SAVE columns of Rule and Zone lines.
267 Changes to past and future timestamps
269 North Korea switches back from +0830 to +09 on 2018-05-05.
270 (Thanks to Kang Seonghoon, Arthur David Olson, Seo Sanghyeon,
273 Bring back the negative-DST changes of 2018a, except be more
274 compatible with data parsers that do not support negative DST.
275 Also, this now affects historical timestamps in Namibia and the
276 former Czechoslovakia, not just Ireland. The main format now uses
277 negative DST to model timestamps in Europe/Dublin (from 1971 on),
278 Europe/Prague (1946/7), and Africa/Windhoek (1994/2017). This
279 does not affect UT offsets, only time zone abbreviations and the
280 tm_isdst flag. Also, this does not affect rearguard or vanguard
281 formats; effectively the main format now uses vanguard instead of
282 rearguard format. Data parsers that do not support negative DST
283 can still use data from the rearguard tarball described below.
285 Changes to build procedure
287 The command 'make tarballs' now also builds the tarball
288 tzdataVERSION-rearguard.tar.gz, which is like tzdataVERSION.tar.gz
289 except that it uses rearguard format intended for trailing-edge
292 Changes to data format and to code
294 The SAVE column of Rule and Zone lines can now have an 's' or 'd'
295 suffix, which specifies whether the adjusted time is standard time
296 or daylight saving time. If no suffix is given, daylight saving
297 time is used if and only if the SAVE column is nonzero; this is
298 the longstanding behavior. Although this new feature is not used
299 in tzdata, it could be used to specify the legal time in Namibia
300 1994-2017, as opposed to the popular time (see below).
302 Changes to past timestamps
304 From 1994 through 2017 Namibia observed DST in winter, not summer.
305 That is, it used negative DST, as Ireland still does. This change
306 does not affect UTC offsets; it affects only the tm_isdst flag and
307 the abbreviation used during summer, which is now CAT, not WAST.
308 Although (as noted by Michael Deckers) summer and winter time were
309 both simply called "standard time" in Namibian law, in common
310 practice winter time was considered to be DST (as noted by Stephen
311 Colebourne). The full effect of this change is only in vanguard
312 and main format; in rearguard format, the tm_isdst flag is still
313 zero in winter and nonzero in summer.
315 In 1946/7 Czechoslovakia also observed negative DST in winter.
316 The full effect of this change is only in vanguard and main
317 formats; in rearguard format, it is modeled as plain GMT without
318 daylight saving. Also, the dates of some 1944/5 DST transitions
319 in Czechoslovakia have been changed.
322 Release 2018d - 2018-03-22 07:05:46 -0700
326 Palestine starts DST a week earlier in 2018.
327 Add support for vanguard and rearguard data consumers.
328 Add subsecond precision to source data format, though not to data.
330 Changes to future timestamps
332 In 2018, Palestine starts DST on March 24, not March 31.
333 Adjust future predictions accordingly. (Thanks to Sharef Mustafa.)
335 Changes to past and future timestamps
337 Casey Station in Antarctica changed from +11 to +08 on 2018-03-11
338 at 04:00. (Thanks to Steffen Thorsen.)
340 Changes to past timestamps
342 Historical transitions for Uruguay, represented by
343 America/Montevideo, have been updated per official legal documents,
344 replacing previous data mainly originating from the inventions of
345 Shanks & Pottenger. This has resulted in adjustments ranging from
346 30 to 90 minutes in either direction over at least two dozen
347 distinct periods ranging from one day to several years in length.
348 A mere handful of pre-1991 transitions are unaffected; data since
349 then has come from more reliable contemporaneous reporting. These
350 changes affect various timestamps in 1920-1923, 1936, 1939,
351 1942-1943, 1959, 1966-1970, 1972, 1974-1980, and 1988-1990.
352 Additionally, Uruguay's pre-standard-time UT offset has been
353 adjusted westward by 7 seconds, from UT-03:44:44 to UT-03:44:51, to
354 match the location of the Observatory of the National Meteorological
355 Institute in Montevideo.
356 (Thanks to Jeremie Bonjour, Tim Parenti, and Michael Deckers.)
358 Enderbury and Kiritimati skipped New Year's Eve 1994, not
359 New Year's Day 1995. (Thanks to Kerry Shetline.)
361 Fix the 1912-01-01 transition for Portugal and its colonies.
362 This transition was at 00:00 according to the new UT offset, not
363 according to the old one. Also assume that Cape Verde switched on
364 the same date as the rest, not in 1907. This affects
365 Africa/Bissau, Africa/Sao_Tome, Asia/Macau, Atlantic/Azores,
366 Atlantic/Cape_Verde, Atlantic/Madeira, and Europe/Lisbon.
367 (Thanks to Michael Deckers.)
369 Fix an off-by-1 error for pre-1913 timestamps in Jamaica and in
372 Changes to past time zone abbreviations
374 MMT took effect in Uruguay from 1908-06-10, not 1898-06-28. There
375 is no clock change associated with the transition.
377 Changes to build procedure
379 The new DATAFORM macro in the Makefile lets the installer choose
380 among three source data formats. The idea is to lessen downstream
381 disruption when data formats are improved.
383 * DATAFORM=vanguard installs from the latest, bleeding-edge
384 format. DATAFORM=main (the default) installs from the format
385 used in the 'africa' etc. files. DATAFORM=rearguard installs
386 from a trailing-edge format. Eventually, elements of today's
387 vanguard format should move to the main format, and similarly
388 the main format's features should eventually move to the
391 * In the current version, the main and rearguard formats are
392 identical and match that of 2018c, so this change does not
393 affect default behavior. The vanguard format currently contains
394 one feature not in the main format: negative SAVE values. This
395 improves support for Ireland, which uses Irish Standard Time
396 (IST, UTC+01) in summer and GMT (UTC) in winter. tzcode has
397 supported negative SAVE values for decades, and this feature
398 should move to the main format soon. However, it will not move
399 to the rearguard format for quite some time because some
400 downstream parsers do not support it.
402 * The build procedure constructs three files vanguard.zi, main.zi,
403 and rearguard.zi, one for each format. The files represent the
404 same data as closely as the formats allow. These three files
405 are intended for downstream data consumers and are not
406 installed. Zoneinfo parsers that do not support negative SAVE values
407 should start using rearguard.zi, so that they will be unaffected
408 when the negative-DST feature moves from vanguard to main.
409 Bleeding-edge Zoneinfo parsers that support the new features
410 already can use vanguard.zi; in this respect, current tzcode is
413 The Makefile should now be safe for parallelized builds, and 'make
414 -j to2050new.tzs' is now much faster on a multiprocessor host
417 When built with -DSUPPRESS_TZDIR, the tzcode library no longer
418 prepends TZDIR/ to file names that do not begin with '/'. This is
419 not recommended for general use, due to its security implications.
420 (From a suggestion by Manuela Friedrich.)
424 zic now accepts subsecond precision in expressions like
425 00:19:32.13, which is approximately the legal time of the
426 Netherlands from 1835 to 1937. However, because it is
427 questionable whether the few recorded uses of non-integer offsets
428 had subsecond precision in practice, there are no plans for tzdata
429 to use this feature. (Thanks to Steve Allen for pointing out
430 the limitations of historical data in this area.)
432 The code is a bit more portable to MS-Windows. Installers can
433 compile with -DRESERVE_STD_EXT_IDS on MS-Windows platforms that
434 reserve identifiers like 'localtime'. (Thanks to Manuela
437 Changes to documentation and commentary
439 theory.html now outlines tzdb's extensions to POSIX's model for
440 civil time, and has a section "POSIX features no longer needed"
441 that lists POSIX API components that are now vestigial.
442 (From suggestions by Steve Summit.) It also better distinguishes
443 time zones from tz regions. (From a suggestion by Guy Harris.)
445 Commentary is now more consistent about using the phrase "daylight
446 saving time", to match the C name tm_isdst. Daylight saving time
447 need not occur in summer, and need not have a positive offset from
450 Commentary about historical transitions in Uruguay has been expanded
451 with links to many relevant legal documents.
452 (Thanks to Tim Parenti.)
454 Commentary now uses some non-ASCII characters with Unicode value
455 less than U+0100, as they can be useful and should work even with
456 older editors such as XEmacs.
459 Release 2018c - 2018-01-22 23:00:44 -0800
462 Revert Irish changes that relied on negative SAVE values.
466 Revert the 2018a change to Europe/Dublin. As before, this change
467 does not affect UT offsets or abbreviations; it affects only
468 whether timestamps are considered to be standard time or
469 daylight-saving time, as expressed in the tm_isdst flag of C's
470 struct tm type. This reversion is intended to be a temporary
471 workaround for problems discovered with downstream uses of
472 releases 2018a and 2018b, which implemented Irish time by using
473 negative SAVE values in the Eire rules of the 'europe' file.
474 Although negative SAVE values have been part of tzcode for many
475 years and are supported by many platforms, they were not
476 documented before 2018a and ICU and OpenJDK do not currently
477 support them. A mechanism to export data to platforms lacking
478 support for negative DST is planned to be developed before the
479 change is reapplied. (Problems reported by Deborah Goldsmith and
482 Changes to past timestamps
484 Japanese DST transitions (1948-1951) were Sundays at 00:00, not
485 Saturdays or Sundays at 02:00. (Thanks to Takayuki Nikai.)
487 Changes to build procedure
489 The build procedure now works around mawk 1.3.3's lack of support
490 for character class expressions. (Problem reported by Ohyama.)
493 Release 2018b - 2018-01-17 23:24:48 -0800
496 Fix a packaging problem in tz2018a, which was missing 'pacificnew'.
498 Changes to build procedure
500 The distribution now contains the file 'pacificnew' again.
501 This file was inadvertantly omitted in the 2018a distribution.
502 (Problem reported by Matias Fonzo.)
505 Release 2018a - 2018-01-12 22:29:21 -0800
508 São Tomé and Príncipe switched from +00 to +01.
509 Brazil's DST will now start on November's first Sunday.
510 Ireland's standard time is now in the summer, not the winter.
511 Use Debian-style installation locations, instead of 4.3BSD-style.
514 Changes to past and future timestamps
516 São Tomé and Príncipe switched from +00 to +01 on 2018-01-01 at
517 01:00. (Thanks to Steffen Thorsen and Michael Deckers.)
519 Changes to future timestamps
521 Starting in 2018 southern Brazil will begin DST on November's
522 first Sunday instead of October's third Sunday. (Thanks to
525 Changes to past timestamps
527 A discrepancy of 4 s in timestamps before 1931 in South Sudan has
528 been corrected. The 'backzone' and 'zone.tab' files did not agree
529 with the 'africa' and 'zone1970.tab' files. (Problem reported by
532 The abbreviation invented for Bolivia Summer Time (1931-2) is now
533 BST instead of BOST, to be more consistent with the convention
534 used for Latvian Summer Time (1918-9) and for British Summer Time.
538 Change Europe/Dublin so that it observes Irish Standard Time (UT
539 +01) in summer and GMT (as negative daylight-saving) in winter,
540 instead of observing standard time (GMT) in winter and Irish
541 Summer Time (UT +01) in summer. This change does not affect UT
542 offsets or abbreviations; it affects only whether timestamps are
543 considered to be standard time or daylight-saving time, as
544 expressed in the tm_isdst flag of C's struct tm type.
545 (Discrepancy noted by Derick Rethans.)
547 Changes to build procedure
549 The default installation locations have been changed to mostly
550 match Debian circa 2017, instead of being designed as an add-on to
551 4.3BSD circa 1986. This affects the Makefile macros TOPDIR,
552 TZDIR, MANDIR, and LIBDIR. New Makefile macros TZDEFAULT, USRDIR,
553 USRSHAREDIR, BINDIR, ZDUMPDIR, and ZICDIR let installers tailor
554 locations more precisely. (This responds to suggestions from
555 Brian Inglis and from Steve Summit.)
557 The default installation procedure no longer creates the
558 backward-compatibility link US/Pacific-New, which causes
559 confusion during user setup (e.g., see Debian bug 815200).
560 Use 'make BACKWARD="backward pacificnew"' to create the link
561 anyway, for now. Eventually we plan to remove the link entirely.
563 tzdata.zi now contains a version-number comment.
564 (Suggested by Tom Lane.)
566 The Makefile now quotes values like BACKWARD more carefully when
567 passing them to the shell. (Problem reported by Zefram.)
569 Builders no longer need to specify -DHAVE_SNPRINTF on platforms
570 that have snprintf and use pre-C99 compilers. (Problem reported
575 zic has a new option -t FILE that specifies the location of the
576 file that determines local time when TZ is unset. The default for
577 this location can be configured via the new TZDEFAULT makefile
578 macro, which defaults to /etc/localtime.
580 Diagnostics and commentary now distinguish UT from UTC more
581 carefully; see theory.html for more information about UT vs UTC.
583 zic has been ported to GCC 8's -Wstringop-truncation option.
584 (Problem reported by Martin Sebor.)
586 Changes to documentation and commentary
588 The zic man page now documents the longstanding behavior that
589 times and years can be out of the usual range, with negative times
590 counting backwards from midnight and with year 0 preceding year 1.
591 (Problem reported by Michael Deckers.)
593 The theory.html file now mentions the POSIX limit of six chars
594 per abbreviation, and lists alphabetic abbreviations used.
596 The files tz-art.htm and tz-link.htm have been renamed to
597 tz-art.html and tz-link.html, respectively, for consistency with
598 other file names and to simplify web server configuration.
601 Release 2017c - 2017-10-20 14:49:34 -0700
604 Northern Cyprus switches from +03 to +02/+03 on 2017-10-29.
605 Fiji ends DST 2018-01-14, not 2018-01-21.
606 Namibia switches from +01/+02 to +02 on 2018-04-01.
607 Sudan switches from +03 to +02 on 2017-11-01.
608 Tonga likely switches from +13/+14 to +13 on 2017-11-05.
609 Turks & Caicos switches from -04 to -05/-04 on 2018-11-04.
610 A new file tzdata.zi now holds a small text copy of all data.
611 The zic input format has been regularized slightly.
613 Changes to future timestamps
615 Northern Cyprus has decided to resume EU rules starting
616 2017-10-29, thus reinstituting winter time.
618 Fiji ends DST 2018-01-14 instead of the 2018-01-21 previously
619 predicted. (Thanks to Dominic Fok.) Adjust future predictions
622 Namibia will switch from +01 with DST to +02 all year on
623 2017-09-03 at 02:00. This affects UT offsets starting 2018-04-01
624 at 02:00. (Thanks to Steffen Thorsen.)
626 Sudan will switch from +03 to +02 on 2017-11-01. (Thanks to Ahmed
627 Atyya and Yahia Abdalla.) South Sudan is not switching, so
628 Africa/Juba is no longer a link to Africa/Khartoum.
630 Tonga has likely ended its experiment with DST, and will not
631 adjust its clocks on 2017-11-05. Although Tonga has not announced
632 whether it will continue to observe DST, the IATA is assuming that
633 it will not. (Thanks to David Wade.)
635 Turks & Caicos will switch from -04 all year to -05 with US DST on
636 2018-03-11 at 03:00. This affects UT offsets starting 2018-11-04
637 at 02:00. (Thanks to Steffen Thorsen.)
639 Changes to past timestamps
641 Namibia switched from +02 to +01 on 1994-03-21, not 1994-04-03.
642 (Thanks to Arthur David Olson.)
644 Detroit did not observe DST in 1967.
646 Use railway time for Asia/Kolkata before 1941, by switching to
647 Madras local time (UT +052110) in 1870, then to IST (UT +0530) in
648 1906. Also, treat 1941-2's +0630 as DST, like 1942-5.
650 Europe/Dublin's 1946 and 1947 fallback transitions occurred at
651 02:00 standard time, not 02:00 DST. (Thanks to Michael Deckers.)
653 Pacific/Apia and Pacific/Pago_Pago switched from Antipodean to
654 American time in 1892, not 1879. (Thanks to Michael Deckers.)
656 Adjust the 1867 transition in Alaska to better reflect the
657 historical record, by changing it to occur on 1867-10-18 at 15:30
658 Sitka time rather than at the start of 1867-10-17 local time.
659 Although strictly speaking this is accurate only for Sitka,
660 the rest of Alaska's blanks need to be filled in somehow.
662 Fix off-by-one errors in UT offsets for Adak and Nome before 1867.
663 (Thanks to Michael Deckers.)
665 Add 7 s to the UT offset in Asia/Yangon before 1920.
667 Changes to zone names
669 Remove Canada/East-Saskatchewan from the 'backward' file, as it
670 exceeded the 14-character limit and was an unused misnomer anyway.
672 Changes to build procedure
674 To support applications that prefer to read time zone data in text
675 form, two zic input files tzdata.zi and leapseconds are now
676 installed by default. The commands 'zic tzdata.zi' and 'zic -L
677 leapseconds tzdata.zi' can reproduce the tzdata binary files
678 without and with leap seconds, respectively. To prevent these two
679 new files from being installed, use 'make TZDATA_TEXT=', and to
680 suppress leap seconds from the tzdata text installation, use 'make
681 TZDATA_TEXT=tzdata.zi'.
683 'make BACKWARD=' now suppresses backward-compatibility names
684 like 'US/Pacific' that are defined in the 'backward' and
687 'make check' now works on systems that lack a UTF-8 locale,
688 or that lack the nsgmls program. Set UTF8_LOCALE to configure
689 the name of a UTF-8 locale, if you have one.
691 Y2K runtime checks are no longer enabled by default. Add
692 -DDEPRECATE_TWO_DIGIT_YEARS to CFLAGS to enable them, instead of
693 adding -DNO_RUN_TIME_WARNINGS_ABOUT_YEAR_2000_PROBLEMS_THANK_YOU
694 to disable them. (New name suggested by Brian Inglis.)
696 The build procedure for zdump now works on AIX 7.1.
697 (Problem reported by Kees Dekker.)
701 zic and the reference runtime now reject multiple leap seconds
702 within 28 days of each other, or leap seconds before the Epoch.
703 As a result, support for double leap seconds, which was
704 obsolescent and undocumented, has been removed. Double leap
705 seconds were an error in the C89 standard; they have never existed
706 in civil timekeeping. (Thanks to Robert Elz and Bradley White for
707 noticing glitches in the code that uncovered this problem.)
709 zic now warns about use of the obsolescent and undocumented -y
710 option, and about use of the obsolescent TYPE field of Rule lines.
712 zic now allows unambiguous abbreviations like "Sa" and "Su" for
713 weekdays; formerly it rejected them due to a bug. Conversely, zic
714 no longer considers non-prefixes to be abbreviations; for example,
715 it no longer accepts "lF" as an abbreviation for "lastFriday".
716 Also, zic warns about the undocumented usage with a "last-"
717 prefix, e.g., "last-Fri".
719 Similarly, zic now accepts the unambiguous abbreviation "L" for
720 "Link" in ordinary context and for "Leap" in leap-second context.
721 Conversely, zic no longer accepts non-prefixes such as "La" as
722 abbreviations for words like "Leap".
724 zic no longer accepts leap second lines in ordinary input, or
725 ordinary lines in leap second input. Formerly, zic sometimes
726 warned about this undocumented usage and handled it incorrectly.
728 The new macro HAVE_TZNAME governs whether the tzname external
729 variable is exported, instead of USG_COMPAT. USG_COMPAT now
730 governs only the external variables "timezone" and "daylight".
731 This change is needed because the three variables are not in the
732 same category: although POSIX requires tzname, it specifies the
733 other two variables as optional. Also, USG_COMPAT is now 1 or 0:
734 if not defined, the code attempts to guess it from other macros.
736 localtime.c and difftime.c no longer require stdio.h, and .c files
737 other than zic.c no longer require sys/wait.h.
739 zdump.c no longer assumes snprintf. (Reported by Jonathan Leffler.)
741 Calculation of time_t extrema works around a bug in GCC 4.8.4
742 (Reported by Stan Shebs and Joseph Myers.)
744 zic.c no longer mistranslates formats of line numbers in non-English
745 locales. (Problem reported by Benno Schulenberg.)
747 Several minor changes have been made to the code to make it a
748 bit easier to port to MS-Windows and Solaris. (Thanks to Kees
749 Dekker for reporting the problems.)
751 Changes to documentation and commentary
753 The two new files 'theory.html' and 'calendars' contain the
754 contents of the removed file 'Theory'. The goal is to document
755 tzdb theory more accessibly.
757 The zic man page now documents abbreviation rules.
759 tz-link.htm now covers how to apply tzdata changes to clients.
760 (Thanks to Jorge Fábregas for the AIX link.) It also mentions MySQL.
762 The leap-seconds.list URL has been updated to something that is
763 more reliable for tzdb. (Thanks to Tim Parenti and Brian Inglis.)
765 Release 2017b - 2017-03-17 07:30:38 -0700
767 Briefly: Haiti has resumed DST.
769 Changes to past and future timestamps
771 Haiti resumed observance of DST in 2017. (Thanks to Steffen Thorsen.)
773 Changes to past timestamps
775 Liberia changed from -004430 to +00 on 1972-01-07, not 1972-05-01.
777 Use "MMT" to abbreviate Liberia's time zone before 1972, as "-004430"
778 is one byte over the POSIX limit. (Problem reported by Derick Rethans.)
782 The reference localtime implementation now falls back on the
783 current US daylight-saving transition rules rather than the
784 1987-2006 rules. This fallback occurs only when (1) the TZ
785 environment variable has a value like "AST4ADT" that asks
786 for daylight saving time but does not specify the rules, (2) there
787 is no file by that name, and (3) the TZDEFRULES file cannot be
788 loaded. (Thanks to Tom Lane.)
791 Release 2017a - 2017-02-28 00:05:36 -0800
793 Briefly: Southern Chile moves from -04/-03 to -03, and Mongolia
796 Changes to future timestamps
798 Mongolia no longer observes DST. (Thanks to Ganbold Tsagaankhuu.)
800 Chile's Region of Magallanes moves from -04/-03 to -03 year-round.
801 Its clocks diverge from America/Santiago starting 2017-05-13 at
802 23:00, hiving off a new zone America/Punta_Arenas. Although the
803 Chilean government says this change expires in May 2019, for now
804 assume it's permanent. (Thanks to Juan Correa and Deborah
805 Goldsmith.) This also affects Antarctica/Palmer.
807 Changes to past timestamps
809 Fix many entries for historical timestamps for Europe/Madrid
810 before 1979, to agree with tables compiled by Pere Planesas of the
811 National Astronomical Observatory of Spain. As a side effect,
812 this changes some timestamps for Africa/Ceuta before 1929, which
813 are probably guesswork anyway. (Thanks to Steve Allen and
814 Pierpaolo Bernardi for the heads-ups, and to Michael Deckers for
815 correcting the 1901 transition.)
817 Ecuador observed DST from 1992-11-28 to 1993-02-05.
818 (Thanks to Alois Treindl.)
820 Asia/Atyrau and Asia/Oral were at +03 (not +04) before 1930-06-21.
821 (Thanks to Stepan Golosunov.)
823 Changes to past and future time zone abbreviations
825 Switch to numeric time zone abbreviations for South America, as
826 part of the ongoing project of removing invented abbreviations.
827 This avoids the need to invent an abbreviation for the new Chilean
828 new zone. Similarly, switch from invented to numeric time zone
829 abbreviations for Afghanistan, American Samoa, the Azores,
830 Bangladesh, Bhutan, the British Indian Ocean Territory, Brunei,
831 Cape Verde, Chatham Is, Christmas I, Cocos (Keeling) Is, Cook Is,
832 Dubai, East Timor, Eucla, Fiji, French Polynesia, Greenland,
833 Indochina, Iran, Iraq, Kiribati, Lord Howe, Macquarie, Malaysia,
834 the Maldives, Marshall Is, Mauritius, Micronesia, Mongolia,
835 Myanmar, Nauru, Nepal, New Caledonia, Niue, Norfolk I, Palau,
836 Papua New Guinea, the Philippines, Pitcairn, Qatar, Réunion, St
837 Pierre & Miquelon, Samoa, Saudi Arabia, Seychelles, Singapore,
838 Solomon Is, Tokelau, Tuvalu, Wake, Vanuatu, Wallis & Futuna, and
839 Xinjiang; for 20-minute daylight saving time in Ghana before 1943;
840 for half-hour daylight saving time in Belize before 1944 and in
841 the Dominican Republic before 1975; and for Canary Islands before
842 1946, for Guinea-Bissau before 1975, for Iceland before 1969, for
843 Indian Summer Time before 1942, for Indonesia before around 1964,
844 for Kenya before 1960, for Liberia before 1973, for Madeira before
845 1967, for Namibia before 1943, for the Netherlands in 1937-9, for
846 Pakistan before 1971, for Western Sahara before 1977, and for
847 Zaporozhye in 1880-1924.
849 For Alaska time from 1900 through 1967, instead of "CAT" use the
850 abbreviation "AST", the abbreviation commonly used at the time
851 (Atlantic Standard Time had not been standardized yet). Use "AWT"
852 and "APT" instead of the invented abbreviations "CAWT" and "CAPT".
854 Use "CST" and "CDT" instead of invented abbreviations for Macau
855 before 1999 and Taiwan before 1938, and use "JST" instead of the
856 invented abbreviation "JCST" for Japan and Korea before 1938.
858 Change to database entry category
860 Move the Pacific/Johnston link from 'australasia' to 'backward',
861 since Johnston is now uninhabited.
865 zic no longer mishandles some transitions in January 2038 when it
866 attempts to work around Qt bug 53071. This fixes a bug affecting
867 Pacific/Tongatapu that was introduced in zic 2016e. localtime.c
868 now contains a workaround, useful when loading a file generated by
869 a buggy zic. (Problem and localtime.c fix reported by Bradley
872 zdump -i now outputs non-hour numeric time zone abbreviations
873 without a colon, e.g., "+0530" rather than "+05:30". This agrees
874 with zic %z and with common practice, and simplifies auditing of
877 zdump is now buildable again with -DUSE_LTZ=0.
878 (Problem reported by Joseph Myers.)
880 zdump.c now always includes private.h, to avoid code duplication
881 with private.h. (Problem reported by Kees Dekker.)
883 localtime.c no longer mishandles early or late timestamps
884 when TZ is set to a POSIX-style string that specifies DST.
885 (Problem reported by Kees Dekker.)
887 date and strftime now cause %z to generate "-0000" instead of
888 "+0000" when the UT offset is zero and the time zone abbreviation
891 Changes to documentation and commentary
893 The 'Theory' file now better documents choice of historical time
894 zone abbreviations. (Problems reported by Michael Deckers.)
896 tz-link.htm now covers leap smearing, which is popular in clouds.
899 Release 2016j - 2016-11-22 23:17:13 -0800
901 Briefly: Saratov, Russia moves from +03 to +04 on 2016-12-04.
903 Changes to future timestamps
905 Saratov, Russia switches from +03 to +04 on 2016-12-04 at 02:00.
906 This hives off a new zone Europe/Saratov from Europe/Volgograd.
907 (Thanks to Yuri Konotopov and Stepan Golosunov.)
909 Changes to past timestamps
911 The new zone Asia/Atyrau for Atyraū Region, Kazakhstan, is like
912 Asia/Aqtau except it switched from +05/+06 to +04/+05 in spring
913 1999, not fall 1994. (Thanks to Stepan Golosunov.)
915 Changes to past time zone abbreviations
917 Asia/Gaza and Asia/Hebron now use "EEST", not "EET", to denote
918 summer time before 1948. The old use of "EET" was a typo.
922 zic no longer mishandles file systems that lack hard links, fixing
923 bugs introduced in 2016g. (Problems reported by Tom Lane.)
924 Also, when the destination already contains symbolic links, zic
925 should now work better on systems where the 'link' system call
926 does not follow symbolic links.
928 Changes to documentation and commentary
930 tz-link.htm now documents the relationship between release version
931 numbers and development-repository commit tags. (Suggested by
934 The 'Theory' file now documents UT.
936 iso3166.tab now accents "Curaçao", and commentary now mentions
937 the names "Cabo Verde" and "Czechia". (Thanks to Jiří Boháč.)
940 Release 2016i - 2016-11-01 23:19:52 -0700
942 Briefly: Cyprus split into two time zones on 2016-10-30, and Tonga
943 reintroduces DST on 2016-11-06.
945 Changes to future timestamps
947 Pacific/Tongatapu begins DST on 2016-11-06 at 02:00, ending on
948 2017-01-15 at 03:00. Assume future observances in Tonga will be
949 from the first Sunday in November through the third Sunday in
950 January, like Fiji. (Thanks to Pulu ʻAnau.) Switch to numeric
951 time zone abbreviations for this zone.
953 Changes to past and future timestamps
955 Northern Cyprus is now +03 year round, causing a split in Cyprus
956 time zones starting 2016-10-30 at 04:00. This creates a zone
957 Asia/Famagusta. (Thanks to Even Scharning and Matt Johnson.)
959 Antarctica/Casey switched from +08 to +11 on 2016-10-22.
960 (Thanks to Steffen Thorsen.)
962 Changes to past timestamps
964 Several corrections were made for pre-1975 timestamps in Italy.
965 These affect Europe/Malta, Europe/Rome, Europe/San_Marino, and
968 First, the 1893-11-01 00:00 transition in Italy used the new UT
969 offset (+01), not the old (+00:49:56). (Thanks to Michael
972 Second, rules for daylight saving in Italy were changed to agree
973 with Italy's National Institute of Metrological Research (INRiM)
974 except for 1944, as follows (thanks to Pierpaolo Bernardi, Brian
975 Inglis, and Michael Deckers):
977 The 1916-06-03 transition was at 24:00, not 00:00.
979 The 1916-10-01, 1919-10-05, and 1920-09-19 transitions were at
982 The 1917-09-30 and 1918-10-06 transitions were at 24:00, not
985 The 1944-09-17 transition was at 03:00, not 01:00. This
986 particular change is taken from Italian law as INRiM's table,
987 (which says 02:00) appears to have a typo here. Also, keep the
988 1944-04-03 transition for Europe/Rome, as Rome was controlled by
991 The 1967-1970 and 1972-1974 fallback transitions were at 01:00,
996 The code should now be buildable on AmigaOS merely by setting the
997 appropriate Makefile variables. (From a patch by Carsten Larsen.)
1000 Release 2016h - 2016-10-19 23:17:57 -0700
1002 Changes to future timestamps
1004 Asia/Gaza and Asia/Hebron end DST on 2016-10-29 at 01:00, not
1005 2016-10-21 at 00:00. (Thanks to Sharef Mustafa.) Predict that
1006 future fall transitions will be on the last Saturday of October
1007 at 01:00, which is consistent with predicted spring transitions
1008 on the last Saturday of March. (Thanks to Tim Parenti.)
1010 Changes to past timestamps
1012 In Turkey, transitions in 1986-1990 were at 01:00 standard time
1013 not at 02:00, and the spring 1994 transition was on March 20, not
1014 March 27. (Thanks to Kıvanç Yazan.)
1016 Changes to past and future time zone abbreviations
1018 Asia/Colombo now uses numeric time zone abbreviations like "+0530"
1019 instead of alphabetic ones like "IST" and "LKT". Various
1020 English-language sources use "IST", "LKT" and "SLST", with no
1021 working consensus. (Usage of "SLST" mentioned by Sadika
1026 zic no longer mishandles relativizing file names when creating
1027 symbolic links like /etc/localtime, when these symbolic links
1028 are outside the usual directory hierarchy. This fixes a bug
1029 introduced in 2016g. (Problem reported by Andreas Stieger.)
1031 Changes to build procedure
1033 New rules 'traditional_tarballs' and 'traditional_signatures' for
1034 building just the traditional-format distribution. (Requested by
1037 The file 'version' is now put into the tzdata tarball too.
1038 (Requested by Howard Hinnant.)
1040 Changes to documentation and commentary
1042 The 'Theory' file now has a section on interface stability.
1043 (Requested by Paul Koning.) It also mentions features like
1044 tm_zone and localtime_rz that have long been supported by the
1047 tz-link.htm has improved coverage of time zone boundaries suitable
1048 for geolocation. (Thanks to heads-ups from Evan Siroky and Matt
1051 The US commentary now mentions Allen and the "day of two noons".
1053 The Fiji commentary mentions the government's 2016-10-03 press
1054 release. (Thanks to Raymond Kumar.)
1057 Release 2016g - 2016-09-13 08:56:38 -0700
1059 Changes to future timestamps
1061 Turkey switched from EET/EEST (+02/+03) to permanent +03,
1062 effective 2016-09-07. (Thanks to Burak AYDIN.) Use "+03" rather
1063 than an invented abbreviation for the new time.
1065 New leap second 2016-12-31 23:59:60 UTC as per IERS Bulletin C 52.
1066 (Thanks to Tim Parenti.)
1068 Changes to past timestamps
1070 For America/Los_Angeles, spring-forward transition times have been
1071 corrected from 02:00 to 02:01 in 1948, and from 02:00 to 01:00 in
1074 For zones using Soviet time on 1919-07-01, transitions to UT-based
1075 time were at 00:00 UT, not at 02:00 local time. The affected
1076 zones are Europe/Kirov, Europe/Moscow, Europe/Samara, and
1077 Europe/Ulyanovsk. (Thanks to Alexander Belopolsky.)
1079 Changes to past and future time zone abbreviations
1081 The Factory zone now uses the time zone abbreviation -00 instead
1082 of a long English-language string, as -00 is now the normal way to
1083 represent an undefined time zone.
1085 Several zones in Antarctica and the former Soviet Union, along
1086 with zones intended for ships at sea that cannot use POSIX TZ
1087 strings, now use numeric time zone abbreviations instead of
1088 invented or obsolete alphanumeric abbreviations. The affected
1089 zones are Antarctica/Casey, Antarctica/Davis,
1090 Antarctica/DumontDUrville, Antarctica/Mawson, Antarctica/Rothera,
1091 Antarctica/Syowa, Antarctica/Troll, Antarctica/Vostok,
1092 Asia/Anadyr, Asia/Ashgabat, Asia/Baku, Asia/Bishkek, Asia/Chita,
1093 Asia/Dushanbe, Asia/Irkutsk, Asia/Kamchatka, Asia/Khandyga,
1094 Asia/Krasnoyarsk, Asia/Magadan, Asia/Omsk, Asia/Sakhalin,
1095 Asia/Samarkand, Asia/Srednekolymsk, Asia/Tashkent, Asia/Tbilisi,
1096 Asia/Ust-Nera, Asia/Vladivostok, Asia/Yakutsk, Asia/Yekaterinburg,
1097 Asia/Yerevan, Etc/GMT-14, Etc/GMT-13, Etc/GMT-12, Etc/GMT-11,
1098 Etc/GMT-10, Etc/GMT-9, Etc/GMT-8, Etc/GMT-7, Etc/GMT-6, Etc/GMT-5,
1099 Etc/GMT-4, Etc/GMT-3, Etc/GMT-2, Etc/GMT-1, Etc/GMT+1, Etc/GMT+2,
1100 Etc/GMT+3, Etc/GMT+4, Etc/GMT+5, Etc/GMT+6, Etc/GMT+7, Etc/GMT+8,
1101 Etc/GMT+9, Etc/GMT+10, Etc/GMT+11, Etc/GMT+12, Europe/Kaliningrad,
1102 Europe/Minsk, Europe/Samara, Europe/Volgograd, and
1103 Indian/Kerguelen. For Europe/Moscow the invented abbreviation MSM
1104 was replaced by +05, whereas MSK and MSD were kept as they are not
1105 our invention and are widely used.
1107 Changes to zone names
1109 Rename Asia/Rangoon to Asia/Yangon, with a backward compatibility link.
1110 (Thanks to David Massoud.)
1114 zic no longer generates binary files containing POSIX TZ-like
1115 strings that disagree with the local time type after the last
1116 explicit transition in the data. This fixes a bug with
1117 Africa/Casablanca and Africa/El_Aaiun in some year-2037 timestamps
1118 on the reference platform. (Thanks to Alexander Belopolsky for
1119 reporting the bug and suggesting a way forward.)
1121 If the installed localtime and/or posixrules files are symbolic
1122 links, zic now keeps them symbolic links when updating them, for
1123 compatibility with platforms like OpenSUSE where other programs
1124 configure these files as symlinks.
1126 zic now avoids hard linking to symbolic links, avoids some
1127 unnecessary mkdir and stat system calls, and uses shorter file
1130 zdump has a new -i option to generate transitions in a
1131 more-compact but still human-readable format. This option is
1132 experimental, and the output format may change in future versions.
1133 (Thanks to Jon Skeet for suggesting that an option was needed,
1134 and thanks to Tim Parenti and Chris Rovick for further comments.)
1136 Changes to build procedure
1138 An experimental distribution format is available, in addition
1139 to the traditional format which will continue to be distributed.
1140 The new format is a tarball tzdb-VERSION.tar.lz with signature
1141 file tzdb-VERSION.tar.lz.asc. It unpacks to a top-level directory
1142 tzdb-VERSION containing the code and data of the traditional
1143 two-tarball format, along with extra data that may be useful.
1144 (Thanks to Antonio Diaz Diaz, Oscar van Vlijmen, and many others
1145 for comments about the experimental format.)
1147 The release version number is now more accurate in the usual case
1148 where releases are built from a Git repository. For example, if
1149 23 commits and some working-file changes have been made since
1150 release 2016g, the version number is now something like
1151 '2016g-23-g50556e3-dirty' instead of the misleading '2016g'.
1152 Tagged releases use the same version number format as before,
1153 e.g., '2016g'. To support the more-accurate version number, its
1154 specification has moved from a line in the Makefile to a new
1155 source file 'version'.
1157 The experimental distribution contains a file to2050.tzs that
1158 contains what should be the output of 'zdump -i -c 2050' on
1159 primary zones. If this file is available, 'make check' now checks
1160 that zdump generates this output.
1162 'make check_web' now works on Fedora-like distributions.
1164 Changes to documentation and commentary
1166 tzfile.5 now documents the new restriction on POSIX TZ-like
1167 strings that is now implemented by zic.
1169 Comments now cite URLs for some 1917-1921 Russian DST decrees.
1170 (Thanks to Alexander Belopolsky.)
1172 tz-link.htm mentions JuliaTime (thanks to Curtis Vogt) and Time4J
1173 (thanks to Meno Hochschild) and ThreeTen-Extra, and its
1174 description of Java 8 has been brought up to date (thanks to
1175 Stephen Colebourne). Its description of local time on Mars has
1176 been updated to match current practice, and URLs have been updated
1177 and some obsolete ones removed.
1180 Release 2016f - 2016-07-05 16:26:51 +0200
1182 Changes affecting future timestamps
1184 The Egyptian government changed its mind on short notice, and
1185 Africa/Cairo will not introduce DST starting 2016-07-07 after all.
1186 (Thanks to Mina Samuel.)
1188 Asia/Novosibirsk switches from +06 to +07 on 2016-07-24 at 02:00.
1189 (Thanks to Stepan Golosunov.)
1191 Changes to past and future timestamps
1193 Asia/Novokuznetsk and Asia/Novosibirsk now use numeric time zone
1194 abbreviations instead of invented ones.
1196 Changes affecting past timestamps
1198 Europe/Minsk's 1992-03-29 spring-forward transition was at 02:00 not 00:00.
1199 (Thanks to Stepan Golosunov.)
1202 Release 2016e - 2016-06-14 08:46:16 -0700
1204 Changes affecting future timestamps
1206 Africa/Cairo observes DST in 2016 from July 7 to the end of October.
1207 Guess October 27 and 24:00 transitions. (Thanks to Steffen Thorsen.)
1208 For future years, guess April's last Thursday to October's last
1209 Thursday except for Ramadan.
1211 Changes affecting past timestamps
1213 Locations while uninhabited now use '-00', not 'zzz', as a
1214 placeholder time zone abbreviation. This is inspired by Internet
1215 RFC 3339 and is more consistent with numeric time zone
1216 abbreviations already used elsewhere. The change affects several
1217 arctic and antarctic locations, e.g., America/Cambridge_Bay before
1218 1920 and Antarctica/Troll before 2005.
1220 Asia/Baku's 1992-09-27 transition from +04 (DST) to +04 (non-DST) was
1221 at 03:00, not 23:00 the previous day. (Thanks to Michael Deckers.)
1225 zic now outputs a dummy transition at time 2**31 - 1 in zones
1226 whose POSIX-style TZ strings contain a '<'. This mostly works
1227 around Qt bug 53071 <https://bugreports.qt.io/browse/QTBUG-53071>.
1228 (Thanks to Zhanibek Adilbekov for reporting the Qt bug.)
1230 Changes affecting documentation and commentary
1232 tz-link.htm says why governments should give plenty of notice for
1233 time zone or DST changes, and refers to Matt Johnson's blog post.
1235 tz-link.htm mentions Tzdata for Elixir. (Thanks to Matt Johnson.)
1238 Release 2016d - 2016-04-17 22:50:29 -0700
1240 Changes affecting future timestamps
1242 America/Caracas switches from -0430 to -04 on 2016-05-01 at 02:30.
1243 (Thanks to Alexander Krivenyshev for the heads-up.)
1245 Asia/Magadan switches from +10 to +11 on 2016-04-24 at 02:00.
1246 (Thanks to Alexander Krivenyshev and Matt Johnson.)
1248 New zone Asia/Tomsk, split off from Asia/Novosibirsk. It covers
1249 Tomsk Oblast, Russia, which switches from +06 to +07 on 2016-05-29
1250 at 02:00. (Thanks to Stepan Golosunov.)
1252 Changes affecting past timestamps
1254 New zone Europe/Kirov, split off from Europe/Volgograd. It covers
1255 Kirov Oblast, Russia, which switched from +04/+05 to +03/+04 on
1256 1989-03-26 at 02:00, roughly a year after Europe/Volgograd made
1257 the same change. (Thanks to Stepan Golosunov.)
1259 Russia and nearby locations had daylight-saving transitions on
1260 1992-03-29 at 02:00 and 1992-09-27 at 03:00, instead of on
1261 1992-03-28 at 23:00 and 1992-09-26 at 23:00. (Thanks to Stepan
1264 Many corrections to historical time in Kazakhstan from 1991
1265 through 2005. (Thanks to Stepan Golosunov.) Replace Kazakhstan's
1266 invented time zone abbreviations with numeric abbreviations.
1268 Changes to commentary
1270 Mention Internet RFCs 7808 (TZDIST) and 7809 (CalDAV time zone references).
1273 Release 2016c - 2016-03-23 00:51:27 -0700
1275 Changes affecting future timestamps
1277 Azerbaijan no longer observes DST. (Thanks to Steffen Thorsen.)
1279 Chile reverts from permanent to seasonal DST. (Thanks to Juan
1280 Correa for the heads-up, and to Tim Parenti for corrections.)
1281 Guess that future transitions are August's and May's second
1282 Saturdays at 24:00 mainland time. Also, call the period from
1283 2014-09-07 through 2016-05-14 daylight saving time instead of
1284 standard time, as that seems more appropriate now.
1286 Changes affecting past timestamps
1288 Europe/Kaliningrad and Europe/Vilnius changed from +03/+04 to
1289 +02/+03 on 1989-03-26, not 1991-03-31. Europe/Volgograd changed
1290 from +04/+05 to +03/+04 on 1988-03-27, not 1989-03-26.
1291 (Thanks to Stepan Golosunov.)
1293 Changes to commentary
1295 Several updates and URLs for historical and proposed Russian changes.
1296 (Thanks to Stepan Golosunov, Matt Johnson, and Alexander Krivenyshev.)
1299 Release 2016b - 2016-03-12 17:30:14 -0800
1303 Starting with release 2016b, some data entries cause zic implementations
1304 derived from tz releases 2005j through 2015e to issue warnings like
1305 "time zone abbreviation differs from POSIX standard (+03)".
1306 These warnings should not otherwise affect zic's output and can safely be
1307 ignored on today's platforms, as the warnings refer to a restriction in
1308 POSIX.1-1988 that was removed in POSIX.1-2001. One way to suppress the
1309 warnings is to upgrade to zic derived from tz releases 2015f and later.
1311 Changes affecting future timestamps
1313 New zones Europe/Astrakhan and Europe/Ulyanovsk for Astrakhan and
1314 Ulyanovsk Oblasts, Russia, both of which will switch from +03 to +04 on
1315 2016-03-27 at 02:00 local time. They need distinct zones since their
1316 post-1970 histories disagree. New zone Asia/Barnaul for Altai Krai and
1317 Altai Republic, Russia, which will switch from +06 to +07 on the same date
1318 and local time. The Astrakhan change is already official; the others have
1319 passed the first reading in the State Duma and are extremely likely.
1320 Also, Asia/Sakhalin moves from +10 to +11 on 2016-03-27 at 02:00.
1321 (Thanks to Alexander Krivenyshev for the heads-up, and to Matt Johnson
1322 and Stepan Golosunov for followup.)
1324 As a trial of a new system that needs less information to be made up,
1325 the new zones use numeric time zone abbreviations like "+04"
1326 instead of invented abbreviations like "ASTT".
1328 Haiti will not observe DST in 2016. (Thanks to Jean Antoine via
1331 Palestine's spring-forward transition on 2016-03-26 is at 01:00, not 00:00.
1332 (Thanks to Hannah Kreitem.) Guess future transitions will be March's last
1333 Saturday at 01:00, not March's last Friday at 24:00.
1335 Changes affecting past timestamps
1337 Europe/Chisinau observed DST during 1990, and switched from +04 to
1338 +03 at 1990-05-06 02:00, instead of switching from +03 to +02.
1339 (Thanks to Stepan Golosunov.)
1341 1991 abbreviations in Europe/Samara should be SAMT/SAMST, not
1342 KUYT/KUYST. (Thanks to Stepan Golosunov.)
1346 tzselect's diagnostics and checking, and checktab.awk's checking,
1347 have been improved. (Thanks to J William Piggott.)
1349 tzcode now builds under MinGW. (Thanks to Ian Abbott and Esben Haabendal.)
1351 tzselect now tests Julian-date TZ settings more accurately.
1352 (Thanks to J William Piggott.)
1354 Changes to commentary
1356 Comments in zone tables have been improved. (Thanks to J William Piggott.)
1358 tzselect again limits its menu comments so that menus fit on a
1359 24×80 alphanumeric display.
1361 A new web page tz-how-to.html. (Thanks to Bill Seymour.)
1363 In the Theory file, the description of possible time zone abbreviations in
1364 tzdata has been cleaned up, as the old description was unclear and
1365 inconsistent. (Thanks to Alain Mouette for reporting the problem.)
1368 Release 2016a - 2016-01-26 23:28:02 -0800
1370 Changes affecting future timestamps
1372 America/Cayman will not observe daylight saving this year after all.
1373 Revert our guess that it would. (Thanks to Matt Johnson.)
1375 Asia/Chita switches from +0800 to +0900 on 2016-03-27 at 02:00.
1376 (Thanks to Alexander Krivenyshev.)
1378 Asia/Tehran now has DST predictions for the year 2038 and later,
1379 to be March 21 00:00 to September 21 00:00. This is likely better
1380 than predicting no DST, albeit off by a day every now and then.
1382 Changes affecting past and future timestamps
1384 America/Metlakatla switched from PST all year to AKST/AKDT on
1385 2015-11-01 at 02:00. (Thanks to Steffen Thorsen.)
1387 America/Santa_Isabel has been removed, and replaced with a
1388 backward compatibility link to America/Tijuana. Its contents were
1389 apparently based on a misreading of Mexican legislation.
1391 Changes affecting past timestamps
1393 Asia/Karachi's two transition times in 2002 were off by a minute.
1394 (Thanks to Matt Johnson.)
1396 Changes affecting build procedure
1398 An installer can now combine leap seconds with use of the backzone file,
1399 e.g., with 'make PACKRATDATA=backzone REDO=posix_right zones'.
1400 The old 'make posix_packrat' rule is now marked as obsolescent.
1401 (Thanks to Ian Abbott for an initial implementation.)
1403 Changes affecting documentation and commentary
1405 A new file LICENSE makes it easier to see that the code and data
1406 are mostly public-domain. (Thanks to James Knight.) The three
1407 non-public-domain files now use the current (3-clause) BSD license
1408 instead of older versions of that license.
1410 tz-link.htm mentions the BDE library (thanks to Andrew Paprocki),
1411 CCTZ (thanks to Tim Parenti), TimeJones.com, and has a new section
1412 on editing tz source files (with a mention of Sublime zoneinfo,
1413 thanks to Gilmore Davidson).
1415 The Theory and asia files now mention the 2015 book "The Global
1416 Transformation of Time, 1870-1950", and cite a couple of reviews.
1418 The America/Chicago entry now documents the informal use of US
1419 central time in Fort Pierre, South Dakota. (Thanks to Rick
1420 McDermid, Matt Johnson, and Steve Jones.)
1423 Release 2015g - 2015-10-01 00:39:51 -0700
1425 Changes affecting future timestamps
1427 Turkey's 2015 fall-back transition is scheduled for Nov. 8, not Oct. 25.
1430 Norfolk moves from +1130 to +1100 on 2015-10-04 at 02:00 local time.
1431 (Thanks to Alexander Krivenyshev.)
1433 Fiji's 2016 fall-back transition is scheduled for January 17, not 24.
1434 (Thanks to Ken Rylander.)
1436 Fort Nelson, British Columbia will not fall back on 2015-11-01. It has
1437 effectively been on MST (-0700) since it advanced its clocks on 2015-03-08.
1438 New zone America/Fort_Nelson. (Thanks to Matt Johnson.)
1440 Changes affecting past timestamps
1442 Norfolk observed DST from 1974-10-27 02:00 to 1975-03-02 02:00.
1444 Changes affecting code
1446 localtime no longer mishandles America/Anchorage after 2037.
1447 (Thanks to Bradley White for reporting the bug.)
1449 On hosts with signed 32-bit time_t, localtime no longer mishandles
1450 Pacific/Fiji after 2038-01-16 14:00 UTC.
1452 The localtime module allows the variables 'timezone', 'daylight',
1453 and 'altzone' to be in common storage shared with other modules,
1454 and declares them in case the system <time.h> does not.
1455 (Problems reported by Kees Dekker.)
1457 On platforms with tm_zone, strftime.c now assumes it is not NULL.
1458 This simplifies the code and is consistent with zdump.c.
1459 (Problem reported by Christos Zoulas.)
1461 Changes affecting documentation
1463 The tzfile man page now documents that transition times denote the
1464 starts (not the ends) of the corresponding time periods.
1465 (Ambiguity reported by Bill Seymour.)
1468 Release 2015f - 2015-08-10 18:06:56 -0700
1470 Changes affecting future timestamps
1472 North Korea switches to +0830 on 2015-08-15. (Thanks to Steffen Thorsen.)
1473 The abbreviation remains "KST". (Thanks to Robert Elz.)
1475 Uruguay no longer observes DST. (Thanks to Steffen Thorsen
1478 Changes affecting past and future timestamps
1480 Moldova starts and ends DST at 00:00 UTC, not at 01:00 UTC.
1481 (Thanks to Roman Tudos.)
1483 Changes affecting data format and code
1485 zic's '-y YEARISTYPE' option is no longer documented. The TYPE
1486 field of a Rule line should now be '-'; the old values 'even',
1487 'odd', 'uspres', 'nonpres', 'nonuspres' were already undocumented.
1488 Although the implementation has not changed, these features do not
1489 work in the default installation, they are not used in the data,
1490 and they are now considered obsolescent.
1492 zic now checks that two rules don't take effect at the same time.
1493 (Thanks to Jon Skeet and Arthur David Olson.) Constraints on
1494 simultaneity are now documented.
1496 The two characters '%z' in a zone format now stand for the UT
1497 offset, e.g., '-07' for seven hours behind UT and '+0530' for
1498 five hours and thirty minutes ahead. This better supports time
1499 zone abbreviations conforming to POSIX.1-2001 and later.
1501 Changes affecting installed data files
1503 Comments for America/Halifax and America/Glace_Bay have been improved.
1504 (Thanks to Brian Inglis.)
1506 Data entries have been simplified for Atlantic/Canary, Europe/Simferopol,
1507 Europe/Sofia, and Europe/Tallinn. This yields slightly smaller
1508 installed data files for Europe/Simferopol and Europe/Tallinn.
1509 It does not affect timestamps. (Thanks to Howard Hinnant.)
1511 Changes affecting code
1513 zdump and zic no longer warn about valid time zone abbreviations
1516 Some Visual Studio 2013 warnings have been suppressed.
1517 (Thanks to Kees Dekker.)
1519 'date' no longer sets the time of day and its -a, -d, -n and -t
1520 options have been removed. Long obsolescent, the implementation
1521 of these features had porting problems. Builders no longer need
1522 to configure HAVE_ADJTIME, HAVE_SETTIMEOFDAY, or HAVE_UTMPX_H.
1523 (Thanks to Kees Dekker for pointing out the problem.)
1525 Changes affecting documentation
1527 The Theory file mentions naming issues earlier, as these seem to be
1528 poorly publicized (thanks to Gilmore Davidson for reporting the problem).
1530 tz-link.htm mentions Time Zone Database Parser (thanks to Howard Hinnant).
1532 Mention that Herbert Samuel introduced the term "Summer Time".
1535 Release 2015e - 2015-06-13 10:56:02 -0700
1537 Changes affecting future timestamps
1539 Morocco will suspend DST from 2015-06-14 03:00 through 2015-07-19 02:00,
1540 not 06-13 and 07-18 as we had guessed. (Thanks to Milamber.)
1542 Assume Cayman Islands will observe DST starting next year, using US rules.
1543 Although it isn't guaranteed, it is the most likely.
1545 Changes affecting data format
1547 The file 'iso3166.tab' now uses UTF-8, so that its entries can better
1548 spell the names of Åland Islands, Côte d'Ivoire, and Réunion.
1550 Changes affecting code
1552 When displaying data, tzselect converts it to the current locale's
1553 encoding if the iconv command works. (Problem reported by random832.)
1555 tzselect no longer mishandles Dominica, fixing a bug introduced
1556 in Release 2014f. (Problem reported by Owen Leibman.)
1558 zic -l no longer fails when compiled with -DTZDEFAULT=\"/etc/localtime\".
1559 This fixes a bug introduced in Release 2014f.
1560 (Problem reported by Leonardo Chiquitto.)
1563 Release 2015d - 2015-04-24 08:09:46 -0700
1565 Changes affecting future timestamps
1567 Egypt will not observe DST in 2015 and will consider canceling it
1568 permanently. For now, assume no DST indefinitely.
1569 (Thanks to Ahmed Nazmy and Tim Parenti.)
1571 Changes affecting past timestamps
1573 America/Whitehorse switched from UT -09 to -08 on 1967-05-28, not
1574 1966-07-01. Also, Yukon's time zone history is documented better.
1575 (Thanks to Brian Inglis and Dennis Ferguson.)
1577 Change affecting past and future time zone abbreviations
1579 The abbreviations for Hawaii-Aleutian standard and daylight times
1580 have been changed from HAST/HADT to HST/HDT, as per US Government
1581 Printing Office style. This affects only America/Adak since 1983,
1582 as America/Honolulu was already using the new style.
1584 Changes affecting code
1586 zic has some minor performance improvements.
1589 Release 2015c - 2015-04-11 08:55:55 -0700
1591 Changes affecting future timestamps
1593 Egypt's spring-forward transition is at 24:00 on April's last Thursday,
1594 not 00:00 on April's last Friday. 2015's transition will therefore be on
1595 Thursday, April 30 at 24:00, not Friday, April 24 at 00:00. Similar fixes
1596 apply to 2026, 2037, 2043, etc. (Thanks to Steffen Thorsen.)
1598 Changes affecting past timestamps
1600 The following changes affect some pre-1991 Chile-related timestamps
1601 in America/Santiago, Antarctica/Palmer, and Pacific/Easter.
1603 The 1910 transition was January 10, not January 1.
1605 The 1918 transition was September 10, not September 1.
1607 The UT -04 time observed from 1932 to 1942 is now considered to
1608 be standard time, not year-round DST.
1610 Santiago observed DST (UT -03) from 1946-07-15 through
1611 1946-08-31, then reverted to standard time, then switched to -05
1614 Assume transitions before 1968 were at 00:00, since we have no data
1617 The spring 1988 transition was 1988-10-09, not 1988-10-02.
1618 The fall 1990 transition was 1990-03-11, not 1990-03-18.
1620 Assume no UT offset change for Pacific/Easter on 1890-01-01,
1621 and omit all transitions on Pacific/Easter from 1942 through 1946
1622 since we have no data suggesting that they existed.
1624 One more zone has been turned into a link, as it differed
1625 from an existing zone only for older timestamps. As usual,
1626 this change affects UT offsets in pre-1970 timestamps only.
1627 The zone's old contents have been moved to the 'backzone' file.
1628 The affected zone is America/Montreal.
1630 Changes affecting commentary
1632 Mention the TZUpdater tool.
1634 Mention "The Time Now". (Thanks to Brandon Ramsey.)
1637 Release 2015b - 2015-03-19 23:28:11 -0700
1639 Changes affecting future timestamps
1641 Mongolia will start observing DST again this year, from the last
1642 Saturday in March at 02:00 to the last Saturday in September at 00:00.
1643 (Thanks to Ganbold Tsagaankhuu.)
1645 Palestine will start DST on March 28, not March 27. Also,
1646 correct the fall 2014 transition from September 26 to October 24.
1647 Adjust future predictions accordingly. (Thanks to Steffen Thorsen.)
1649 Changes affecting past timestamps
1651 The 1982 zone shift in Pacific/Easter has been corrected, fixing a 2015a
1652 regression. (Thanks to Stuart Bishop for reporting the problem.)
1654 Some more zones have been turned into links, when they differed
1655 from existing zones only for older timestamps. As usual,
1656 these changes affect UT offsets in pre-1970 timestamps only.
1657 Their old contents have been moved to the 'backzone' file.
1658 The affected zones are: America/Antigua, America/Cayman,
1659 Pacific/Midway, and Pacific/Saipan.
1661 Changes affecting time zone abbreviations
1663 Correct the 1992-2010 DST abbreviation in Volgograd from "MSK" to "MSD".
1666 Changes affecting code
1668 Fix integer overflow bug in reference 'mktime' implementation.
1669 (Problem reported by Jörg Richter.)
1671 Allow -Dtime_tz=time_t compilations, and allow -Dtime_tz=... libraries
1672 to be used in the same executable as standard-library time_t functions.
1673 (Problems reported by Bradley White.)
1675 Changes affecting commentary
1677 Cite the recent Mexican decree changing Quintana Roo's time zone.
1678 (Thanks to Carlos Raúl Perasso.)
1680 Likewise for the recent Chilean decree. (Thanks to Eduardo Romero Urra.)
1682 Update info about Mars time.
1685 Release 2015a - 2015-01-29 22:35:20 -0800
1687 Changes affecting future timestamps
1689 The Mexican state of Quintana Roo, represented by America/Cancun,
1690 will shift from Central Time with DST to Eastern Time without DST
1691 on 2015-02-01 at 02:00. (Thanks to Steffen Thorsen and Gwillim Law.)
1693 Chile will not change clocks in April or thereafter; its new standard time
1694 will be its old daylight saving time. This affects America/Santiago,
1695 Pacific/Easter, and Antarctica/Palmer. (Thanks to Juan Correa.)
1697 New leap second 2015-06-30 23:59:60 UTC as per IERS Bulletin C 49.
1698 (Thanks to Tim Parenti.)
1700 Changes affecting past timestamps
1702 Iceland observed DST in 1919 and 1921, and its 1939 fallback
1703 transition was Oct. 29, not Nov. 29. Remove incorrect data from
1704 Shanks about time in Iceland between 1837 and 1908.
1706 Some more zones have been turned into links, when they differed
1707 from existing zones only for older timestamps. As usual,
1708 these changes affect UT offsets in pre-1970 timestamps only.
1709 Their old contents have been moved to the 'backzone' file.
1710 The affected zones are: Asia/Aden, Asia/Bahrain, Asia/Kuwait,
1713 Changes affecting code
1715 tzalloc now scrubs time zone abbreviations compatibly with the way
1716 that tzset always has, by replacing invalid bytes with '_' and by
1717 shortening too-long abbreviations.
1719 tzselect ports to POSIX awk implementations, no longer mishandles
1720 POSIX TZ settings when GNU awk is used, and reports POSIX TZ
1721 settings to the user. (Thanks to Stefan Kuhn.)
1723 Changes affecting build procedure
1725 'make check' now checks for links to links in the data.
1726 One such link (for Africa/Asmera) has been fixed.
1727 (Thanks to Stephen Colebourne for pointing out the problem.)
1729 Changes affecting commentary
1731 The leapseconds file commentary now mentions the expiration date.
1732 (Problem reported by Martin Burnicki.)
1734 Update Mexican Library of Congress URL.
1737 Release 2014j - 2014-11-10 17:37:11 -0800
1739 Changes affecting current and future timestamps
1741 Turks & Caicos' switch from US eastern time to UT -04 year-round
1742 did not occur on 2014-11-02 at 02:00. It's currently scheduled
1743 for 2015-11-01 at 02:00. (Thanks to Chris Walton.)
1745 Changes affecting past timestamps
1747 Many pre-1989 timestamps have been corrected for Asia/Seoul and
1748 Asia/Pyongyang, based on sources for the Korean-language Wikipedia
1749 entry for time in Korea. (Thanks to Sanghyuk Jung.) Also, no
1750 longer guess that Pyongyang mimicked Seoul time after World War II,
1751 as this is politically implausible.
1753 Some more zones have been turned into links, when they differed
1754 from existing zones only for older timestamps. As usual,
1755 these changes affect UT offsets in pre-1970 timestamps only.
1756 Their old contents have been moved to the 'backzone' file.
1757 The affected zones are: Africa/Addis_Ababa, Africa/Asmara,
1758 Africa/Dar_es_Salaam, Africa/Djibouti, Africa/Kampala,
1759 Africa/Mogadishu, Indian/Antananarivo, Indian/Comoro, and
1762 Changes affecting commentary
1764 The commentary is less enthusiastic about Shanks as a source,
1765 and is more careful to distinguish UT from UTC.
1768 Release 2014i - 2014-10-21 22:04:57 -0700
1770 Changes affecting future timestamps
1772 Pacific/Fiji will observe DST from 2014-11-02 02:00 to 2015-01-18 03:00.
1773 (Thanks to Ken Rylander for the heads-up.) Guess that future
1774 years will use a similar pattern.
1776 A new Zone Pacific/Bougainville, for the part of Papua New Guinea
1777 that plans to switch from UT +10 to +11 on 2014-12-28 at 02:00.
1778 (Thanks to Kiley Walbom for the heads-up.)
1780 Changes affecting time zone abbreviations
1782 Since Belarus is not changing its clocks even though Moscow is,
1783 the time zone abbreviation in Europe/Minsk is changing from FET
1784 to its more-traditional value MSK on 2014-10-26 at 01:00.
1785 (Thanks to Alexander Bokovoy for the heads-up about Belarus.)
1787 The new abbreviation IDT stands for the pre-1976 use of UT +08 in
1788 Indochina, to distinguish it better from ICT (+07).
1790 Changes affecting past timestamps
1792 Many timestamps have been corrected for Asia/Ho_Chi_Minh before 1976
1793 (thanks to Trần Ngọc Quân for an indirect pointer to Trần Tiến Bình's
1794 authoritative book). Asia/Ho_Chi_Minh has been added to
1795 zone1970.tab, to give tzselect users in Vietnam two choices,
1796 since north and south Vietnam disagreed after our 1970 cutoff.
1798 Asia/Phnom_Penh and Asia/Vientiane have been turned into links, as
1799 they differed from existing zones only for older timestamps. As
1800 usual, these changes affect pre-1970 timestamps only. Their old
1801 contents have been moved to the 'backzone' file.
1803 Changes affecting code
1805 The time-related library functions now set errno on failure, and
1806 some crashes in the new tzalloc-related library functions have
1807 been fixed. (Thanks to Christos Zoulas for reporting most of
1808 these problems and for suggesting fixes.)
1810 If USG_COMPAT is defined and the requested timestamp is standard time,
1811 the tz library's localtime and mktime functions now set the extern
1812 variable timezone to a value appropriate for that timestamp; and
1813 similarly for ALTZONE, daylight saving time, and the altzone variable.
1814 This change is a companion to the tzname change in 2014h, and is
1815 designed to make timezone and altzone more compatible with tzname.
1817 The tz library's functions now set errno to EOVERFLOW if they fail
1818 because the result cannot be represented. ctime and ctime_r now
1819 return NULL and set errno when a timestamp is out of range, rather
1820 than having undefined behavior.
1822 Some bugs associated with the new 2014g functions have been fixed.
1823 This includes a bug that largely incapacitated the new functions
1824 time2posix_z and posix2time_z. (Thanks to Christos Zoulas.)
1825 It also includes some uses of uninitialized variables after tzalloc.
1826 The new code uses the standard type 'ssize_t', which the Makefile
1827 now gives porting advice about.
1829 Changes affecting commentary
1831 Updated URLs for NRC Canada (thanks to Matt Johnson and Brian Inglis).
1834 Release 2014h - 2014-09-25 18:59:03 -0700
1836 Changes affecting past timestamps
1838 America/Jamaica's 1974 spring-forward transition was Jan. 6, not Apr. 28.
1840 Shanks says Asia/Novokuznetsk switched from LMT (not "NMT") on 1924-05-01,
1841 not 1920-01-06. The old entry was based on a misinterpretation of Shanks.
1843 Some more zones have been turned into links, when they differed
1844 from existing zones only for older timestamps. As usual,
1845 these changes affect UT offsets in pre-1970 timestamps only.
1846 Their old contents have been moved to the 'backzone' file.
1847 The affected zones are: Africa/Blantyre, Africa/Bujumbura,
1848 Africa/Gaborone, Africa/Harare, Africa/Kigali, Africa/Lubumbashi,
1849 Africa/Lusaka, Africa/Maseru, and Africa/Mbabane.
1851 Changes affecting code
1853 zdump -V and -v now output gmtoff= values on all platforms,
1854 not merely on platforms defining TM_GMTOFF.
1856 The tz library's localtime and mktime functions now set tzname to a value
1857 appropriate for the requested timestamp, and zdump now uses this
1858 on platforms not defining TM_ZONE, fixing a 2014g regression.
1859 (Thanks to Tim Parenti for reporting the problem.)
1861 The tz library no longer sets tzname if localtime or mktime fails.
1863 zdump -c no longer mishandles transitions near year boundaries.
1864 (Thanks to Tim Parenti for reporting the problem.)
1866 An access to uninitialized data has been fixed.
1867 (Thanks to Jörg Richter for reporting the problem.)
1869 When THREAD_SAFE is defined, the code ports to the C11 memory model.
1870 A memory leak has been fixed if ALL_STATE and THREAD_SAFE are defined
1871 and two threads race to initialize data used by gmtime-like functions.
1872 (Thanks to Andy Heninger for reporting the problems.)
1874 Changes affecting build procedure
1876 'make check' now checks better for properly-sorted data.
1878 Changes affecting documentation and commentary
1880 zdump's gmtoff=N output is now documented, and its isdst=D output
1881 is now documented to possibly output D values other than 0 or 1.
1883 zdump -c's treatment of years is now documented to use the
1884 Gregorian calendar and Universal Time without leap seconds,
1885 and its behavior at cutoff boundaries is now documented better.
1886 (Thanks to Arthur David Olson and Tim Parenti for reporting the problems.)
1888 Programs are now documented to use the proleptic Gregorian calendar.
1889 (Thanks to Alan Barrett for the suggestion.)
1891 Fractional-second GMT offsets have been documented for civil time
1892 in 19th-century Chennai, Jakarta, and New York.
1895 Release 2014g - 2014-08-28 12:31:23 -0700
1897 Changes affecting future timestamps
1899 Turks & Caicos is switching from US eastern time to UT -04
1900 year-round, modeled as a switch on 2014-11-02 at 02:00.
1901 [As noted in 2014j, this switch was later delayed.]
1903 Changes affecting past timestamps
1905 Time in Russia or the USSR before 1926 or so has been corrected by
1906 a few seconds in the following zones: Asia/Irkutsk,
1907 Asia/Krasnoyarsk, Asia/Omsk, Asia/Samarkand, Asia/Tbilisi,
1908 Asia/Vladivostok, Asia/Yakutsk, Europe/Riga, Europe/Samara. For
1909 Asia/Yekaterinburg the correction is a few minutes. (Thanks to
1910 Vladimir Karpinsky.)
1912 The Portuguese decree of 1911-05-26 took effect on 1912-01-01.
1913 This affects 1911 timestamps in Africa/Bissau, Africa/Luanda,
1914 Atlantic/Azores, and Atlantic/Madeira. Also, Lisbon's pre-1912
1915 GMT offset was -0:36:45 (rounded from -0:36:44.68), not -0:36:32.
1916 (Thanks to Stephen Colebourne for pointing to the decree.)
1918 Asia/Dhaka ended DST on 2009-12-31 at 24:00, not 23:59.
1920 A new file 'backzone' contains data which may appeal to
1921 connoisseurs of old timestamps, although it is out of scope for
1922 the tz database, is often poorly sourced, and contains some data
1923 that is known to be incorrect. The new file is not recommended
1924 for ordinary use and its entries are not installed by default.
1925 (Thanks to Lester Caine for the high-quality Jersey, Guernsey, and
1926 Isle of Man entries.)
1928 Some more zones have been turned into links, when they differed
1929 from existing zones only for older timestamps. As usual,
1930 these changes affect UT offsets in pre-1970 timestamps only.
1931 Their old contents have been moved to the 'backzone' file.
1932 The affected zones are: Africa/Bangui, Africa/Brazzaville,
1933 Africa/Douala, Africa/Kinshasa, Africa/Libreville, Africa/Luanda,
1934 Africa/Malabo, Africa/Niamey, and Africa/Porto-Novo.
1936 Changes affecting code
1938 Unless NETBSD_INSPIRED is defined to 0, the tz library now
1939 supplies functions for creating and using objects that represent
1940 timezones. The new functions are tzalloc, tzfree, localtime_rz,
1941 mktime_z, and (if STD_INSPIRED is also defined) posix2time_z and
1942 time2posix_z. They are intended for performance: for example,
1943 localtime_rz (unlike localtime_r) is trivially thread-safe without
1944 locking. (Thanks to Christos Zoulas for proposing NetBSD-inspired
1945 functions, and to Alan Barrett and Jonathan Lennox for helping to
1948 zdump now builds with the tz library unless USE_LTZ is defined to 0,
1949 This lets zdump use tz features even if the system library lacks them.
1950 To build zdump with the system library, use 'make CFLAGS=-DUSE_LTZ=0
1951 TZDOBJS=zdump.o CHECK_TIME_T_ALTERNATIVES='.
1953 zdump now uses localtime_rz if available, as it's significantly faster,
1954 and it can help zdump better diagnose invalid timezone names.
1955 Define HAVE_LOCALTIME_RZ to 0 to suppress this. HAVE_LOCALTIME_RZ
1956 defaults to 1 if NETBSD_INSPIRED && USE_LTZ. When localtime_rz is
1957 not available, zdump now uses localtime_r and tzset if available,
1958 as this is a bit cleaner and faster than plain localtime. Compile
1959 with -DHAVE_LOCALTIME_R=0 and/or -DHAVE_TZSET=0 if your system
1960 lacks these two functions.
1962 If THREAD_SAFE is defined to 1, the tz library is now thread-safe.
1963 Although not needed for tz's own applications, which are single-threaded,
1964 this supports POSIX better if the tz library is used in multithreaded apps.
1966 Some crashes have been fixed when zdump or the tz library is given
1967 invalid or outlandish input.
1969 The tz library no longer mishandles leap seconds on platforms with
1970 unsigned time_t in timezones that lack ordinary transitions after 1970.
1972 The tz code now attempts to infer TM_GMTOFF and TM_ZONE if not
1973 already defined, to make it easier to configure on common platforms.
1974 Define NO_TM_GMTOFF and NO_TM_ZONE to suppress this.
1976 Unless the new macro UNINIT_TRAP is defined to 1, the tz code now
1977 assumes that reading uninitialized memory yields garbage values
1978 but does not cause other problems such as traps.
1980 If TM_GMTOFF is defined and UNINIT_TRAP is 0, mktime is now
1981 more likely to guess right for ambiguous timestamps near
1982 transitions where tm_isdst does not change.
1984 If HAVE_STRFTIME_L is defined to 1, the tz library now defines
1985 strftime_l for compatibility with recent versions of POSIX.
1986 Only the C locale is supported, though. HAVE_STRFTIME_L defaults
1987 to 1 on recent POSIX versions, and to 0 otherwise.
1989 tzselect -c now uses a hybrid distance measure that works better
1990 in Africa. (Thanks to Alan Barrett for noting the problem.)
1992 The C source code now ports to NetBSD when GCC_DEBUG_FLAGS is used,
1993 or when time_tz is defined.
1995 When HAVE_UTMPX_H is set the 'date' command now builds on systems
1996 whose <utmpx.h> file does not define WTMPX_FILE, and when setting
1997 the date it updates the wtmpx file if _PATH_WTMPX is defined.
1998 This affects GNU/Linux and similar systems.
2000 For easier maintenance later, some C code has been simplified,
2001 some lint has been removed, and the code has been tweaked so that
2002 plain 'make' is more likely to work.
2004 The C type 'bool' is now used for boolean values, instead of 'int'.
2006 The long-obsolete LOCALE_HOME code has been removed.
2008 The long-obsolete 'gtime' function has been removed.
2010 Changes affecting build procedure
2012 'zdump' no longer links in ialloc.o, as it's not needed.
2014 'make check_time_t_alternatives' no longer assumes GNU diff.
2016 Changes affecting distribution tarballs
2018 The files checktab.awk and zoneinfo2tdf.pl are now distributed in
2019 the tzdata tarball instead of the tzcode tarball, since they help
2020 maintain the data. The NEWS and Theory files are now also
2021 distributed in the tzdata tarball, as they're relevant for data.
2022 (Thanks to Alan Barrett for pointing this out.) Also, the
2023 leapseconds.awk file is no longer distributed in the tzcode
2024 tarball, since it belongs in the tzdata tarball (where 2014f
2025 inadvertently also distributed it).
2027 Changes affecting documentation and commentary
2029 A new file CONTRIBUTING is distributed. (Thanks to Tim Parenti for
2030 suggesting a CONTRIBUTING file, and to Tony Finch and Walter Harms
2033 The man pages have been updated to use function prototypes,
2034 to document thread-safe variants like localtime_r, and to document
2035 the NetBSD-inspired functions tzalloc, tzfree, localtime_rz, and
2038 The fields in Link lines have been renamed to be more descriptive
2039 and more like the parameters of 'ln'. LINK-FROM has become TARGET,
2040 and LINK-TO has become LINK-NAME.
2042 tz-link.htm mentions the IETF's tzdist working group; Windows
2043 Runtime etc. (thanks to Matt Johnson); and HP-UX's tztab.
2045 Some broken URLs have been fixed in the commentary. (Thanks to
2048 Commentary about Philippines DST has been updated, and commentary
2049 on pre-1970 time in India has been added.
2052 Release 2014f - 2014-08-05 17:42:36 -0700
2054 Changes affecting future timestamps
2056 Russia will subtract an hour from most of its time zones on 2014-10-26
2057 at 02:00 local time. (Thanks to Alexander Krivenyshev.)
2058 There are a few exceptions: Magadan Oblast (Asia/Magadan) and Zabaykalsky
2059 Krai are subtracting two hours; conversely, Chukotka Autonomous Okrug
2060 (Asia/Anadyr), Kamchatka Krai (Asia/Kamchatka), Kemerovo Oblast
2061 (Asia/Novokuznetsk), and the Samara Oblast and the Udmurt Republic
2062 (Europe/Samara) are not changing their clocks. The changed zones are
2063 Europe/Kaliningrad, Europe/Moscow, Europe/Simferopol, Europe/Volgograd,
2064 Asia/Yekaterinburg, Asia/Omsk, Asia/Novosibirsk, Asia/Krasnoyarsk,
2065 Asia/Irkutsk, Asia/Yakutsk, Asia/Vladivostok, Asia/Khandyga,
2066 Asia/Sakhalin, and Asia/Ust-Nera; Asia/Magadan will have two hours
2067 subtracted; and Asia/Novokuznetsk's time zone abbreviation is affected,
2068 but not its UTC offset. Two zones are added: Asia/Chita (split
2069 from Asia/Yakutsk, and also with two hours subtracted) and
2070 Asia/Srednekolymsk (split from Asia/Magadan, but with only one hour
2071 subtracted). (Thanks to Tim Parenti for much of the above.)
2073 Changes affecting time zone abbreviations
2075 Australian eastern time zone abbreviations are now AEST/AEDT not EST,
2076 and similarly for the other Australian zones. That is, for eastern
2077 standard and daylight saving time the abbreviations are AEST and AEDT
2078 instead of the former EST for both; similarly, ACST/ACDT, ACWST/ACWDT,
2079 and AWST/AWDT are now used instead of the former CST, CWST, and WST.
2080 This change does not affect UT offsets, only time zone abbreviations.
2081 (Thanks to Rich Tibbett and many others.)
2083 Asia/Novokuznetsk shifts from NOVT to KRAT (remaining on UT +07)
2084 effective 2014-10-26 at 02:00 local time.
2086 The time zone abbreviation for Xinjiang Time (observed in Ürümqi)
2087 has been changed from URUT to XJT. (Thanks to Luther Ma.)
2089 Prefer MSK/MSD for Moscow time in Russia, even in other cities.
2090 Similarly, prefer EET/EEST for eastern European time in Russia.
2092 Change time zone abbreviations in (western) Samoa to use "ST" and
2093 "DT" suffixes, as this is more likely to match common practice.
2094 Prefix "W" to (western) Samoa time when its standard-time offset
2095 disagrees with that of American Samoa.
2097 America/Metlakatla now uses PST, not MeST, to abbreviate its time zone.
2099 Time zone abbreviations have been updated for Japan's two time
2100 zones used 1896-1937. JWST now stands for Western Standard
2101 Time, and JCST for Central Standard Time (formerly this was CJT).
2102 These abbreviations are now used for time in Korea, Taiwan,
2103 and Sakhalin while controlled by Japan.
2105 Changes affecting past timestamps
2107 China's five zones have been simplified to two, since the post-1970
2108 differences in the other three seem to have been imaginary. The
2109 zones Asia/Harbin, Asia/Chongqing, and Asia/Kashgar have been
2110 removed; backwards-compatibility links still work, albeit with
2111 different behaviors for timestamps before May 1980. Asia/Urumqi's
2112 1980 transition to UT +08 has been removed, so that it is now at
2113 +06 and not +08. (Thanks to Luther Ma and to Alois Treindl;
2114 Treindl sent helpful translations of two papers by Guo Qingsheng.)
2116 Some zones have been turned into links, when they differed from existing
2117 zones only for older UT offsets where data entries were likely invented.
2118 These changes affect UT offsets in pre-1970 timestamps only. This is
2119 similar to the change in release 2013e, except this time for western
2120 Africa. The affected zones are: Africa/Bamako, Africa/Banjul,
2121 Africa/Conakry, Africa/Dakar, Africa/Freetown, Africa/Lome,
2122 Africa/Nouakchott, Africa/Ouagadougou, Africa/Sao_Tome, and
2123 Atlantic/St_Helena. This also affects the backwards-compatibility
2124 link Africa/Timbuktu. (Thanks to Alan Barrett, Stephen Colebourne,
2125 Tim Parenti, and David Patte for reporting problems in earlier
2126 versions of this change.)
2128 Asia/Shanghai's pre-standard-time UT offset has been changed from
2129 8:05:57 to 8:05:43, the location of Xujiahui Observatory. Its
2130 transition to standard time has been changed from 1928 to 1901.
2132 Asia/Taipei switched to JWST on 1896-01-01, then to JST on 1937-10-01,
2133 then to CST on 1945-09-21 at 01:00, and did not observe DST in 1945.
2134 In 1946 it observed DST from 05-15 through 09-30; in 1947
2135 from 04-15 through 10-31; and in 1979 from 07-01 through 09-30.
2136 (Thanks to Yu-Cheng Chuang.)
2138 Asia/Riyadh's transition to standard time is now 1947-03-14, not 1950.
2140 Europe/Helsinki's 1942 fall-back transition was 10-04 at 01:00, not
2141 10-03 at 00:00. (Thanks to Konstantin Hyppönen.)
2143 Pacific/Pago_Pago has been changed from UT -11:30 to -11 for the
2144 period from 1911 to 1950.
2146 Pacific/Chatham has been changed to New Zealand standard time plus
2147 45 minutes for the period before 1957, reflecting a 1956 remark in
2148 the New Zealand parliament.
2150 Europe/Budapest has several pre-1946 corrections: in 1918 the transition
2151 out of DST was on 09-16, not 09-29; in 1919 it was on 11-24, not 09-15; in
2152 1945 it was on 11-01, not 11-03; in 1941 the transition to DST was 04-08
2153 not 04-06 at 02:00; and there was no DST in 1920.
2155 Africa/Accra is now assumed to have observed DST from 1920 through 1935.
2157 Time in Russia before 1927 or so has been corrected by a few seconds in
2158 the following zones: Europe/Moscow, Asia/Irkutsk, Asia/Tbilisi,
2159 Asia/Tashkent, Asia/Vladivostok, Asia/Yekaterinburg, Europe/Helsinki, and
2160 Europe/Riga. Also, Moscow's location has been changed to its Kilometer 0
2161 point. (Thanks to Vladimir Karpinsky for the Moscow changes.)
2163 Changes affecting data format
2165 A new file 'zone1970.tab' supersedes 'zone.tab' in the installed data.
2166 The new file's extended format allows multiple country codes per zone.
2167 The older file is still installed but is deprecated; its format is
2168 not changing and it will still be distributed for a while, but new
2169 applications should use the new file.
2171 The new file format simplifies maintenance of obscure locations.
2172 To test this, it adds coverage for the Crozet Islands and the
2173 Scattered Islands. (Thanks to Tobias Conradi and Antoine Leca.)
2175 The file 'iso3166.tab' is planned to switch from ASCII to UTF-8.
2176 It is still ASCII now, but commentary about the switch has been added.
2177 The new file 'zone1970.tab' already uses UTF-8.
2179 Changes affecting code
2181 'localtime', 'mktime', etc. now use much less stack space if ALL_STATE
2182 is defined. (Thanks to Elliott Hughes for reporting the problem.)
2184 'zic' no longer mishandles input when ignoring case in locales that
2185 are not compatible with English, e.g., unibyte Turkish locales when
2186 compiled with HAVE_GETTEXT.
2188 Error diagnostics of 'zic' and 'yearistype' have been reworded so that
2189 they no longer use ASCII '-' as if it were a dash.
2191 'zic' now rejects output file names that contain '.' or '..' components.
2192 (Thanks to Tim Parenti for reporting the problem.)
2194 'zic -v' now warns about output file names that do not follow
2195 POSIX rules, or that contain a digit or '.'. (Thanks to Arthur
2196 David Olson for starting the ball rolling on this.)
2198 Some lint has been removed when using GCC_DEBUG_FLAGS with GCC 4.9.0.
2200 Changes affecting build procedure
2202 'zic' no longer links in localtime.o and asctime.o, as they're not needed.
2203 (Thanks to John Cochran.)
2205 Changes affecting documentation and commentary
2207 The 'Theory' file documents legacy names, the longstanding
2208 exceptions to the POSIX-inspired file name rules.
2210 The 'zic' documentation clarifies the role of time types when
2211 interpreting dates. (Thanks to Arthur David Olson.)
2213 Documentation and commentary now prefer UTF-8 to US-ASCII,
2214 allowing the use of proper accents in foreign words and names.
2215 Code and data have not changed because of this. (Thanks to
2216 Garrett Wollman, Ian Abbott, and Guy Harris for helping to debug
2219 Non-HTML documentation and commentary now use plain-text URLs instead of
2220 HTML insertions, and are more consistent about bracketing URLs when they
2221 are not already surrounded by white space. (Thanks to suggestions by
2224 There is new commentary about Xujiahui Observatory, the five time-zone
2225 project in China from 1918 to 1949, timekeeping in Japanese-occupied
2226 Shanghai, and Tibet Time in the 1950s. The sharp-eyed can spot the
2227 warlord Jin Shuren in the data.
2229 Commentary about the coverage of each Russian zone has been standardized.
2230 (Thanks to Tim Parenti).
2232 There is new commentary about contemporary timekeeping in Ethiopia.
2234 Obsolete comments about a 2007 proposal for DST in Kuwait has been removed.
2236 There is new commentary about time in Poland in 1919.
2238 Proper credit has been given to DST inventor George Vernon Hudson.
2240 Commentary about time in Metlakatla, AK and Resolute, NU has been
2241 improved, with a new source for the former.
2243 In zone.tab, Pacific/Easter no longer mentions Salas y Gómez, as it
2246 Commentary about permanent Antarctic bases has been updated.
2248 Several typos have been corrected. (Thanks to Tim Parenti for
2249 contributing some of these fixes.)
2251 tz-link.htm now mentions the JavaScript libraries Moment Timezone,
2252 TimezoneJS.Date, Walltime-js, and Timezone. (Thanks to a heads-up
2253 from Matt Johnson.) Also, it mentions the Go 'latlong' package.
2254 (Thanks to a heads-up from Dirkjan Ochtman.)
2256 The files usno1988, usno1989, usno1989a, usno1995, usno1997, and usno1998
2257 have been removed. These obsolescent US Naval Observatory entries were no
2258 longer helpful for maintenance. (Thanks to Tim Parenti for the suggestion.)
2261 Release 2014e - 2014-06-12 21:53:52 -0700
2263 Changes affecting near-future timestamps
2265 Egypt's 2014 Ramadan-based transitions are June 26 and July 31 at 24:00.
2266 (Thanks to Imed Chihi.) Guess that from 2015 on Egypt will temporarily
2267 switch to standard time at 24:00 the last Thursday before Ramadan, and
2268 back to DST at 00:00 the first Friday after Ramadan.
2270 Similarly, Morocco's are June 28 at 03:00 and August 2 at 02:00. (Thanks
2271 to Milamber Space Network.) Guess that from 2015 on Morocco will
2272 temporarily switch to standard time at 03:00 the last Saturday before
2273 Ramadan, and back to DST at 02:00 the first Saturday after Ramadan.
2275 Changes affecting past timestamps
2277 The abbreviation "MSM" (Moscow Midsummer Time) is now used instead of
2278 "MSD" for Moscow's double daylight time in summer 1921. Also, a typo
2279 "VLASST" has been repaired to be "VLAST" for Vladivostok summer time
2280 in 1991. (Thanks to Hank W. for reporting the problems.)
2282 Changes affecting commentary
2284 tz-link.htm now cites RFC 7265 for jCal, mentions PTP and the
2285 draft CalDAV extension, updates URLs for TSP, TZInfo, IATA, and
2286 removes stale pointers to World Time Explorer and WORLDTIME.
2289 Release 2014d - 2014-05-27 21:34:40 -0700
2291 Changes affecting code
2293 zic no longer generates files containing timestamps before the Big Bang.
2294 This works around GNOME glib bug 878
2295 <https://gitlab.gnome.org/GNOME/glib/issues/878>
2296 (Thanks to Leonardo Chiquitto for reporting the bug, and to
2297 Arthur David Olson and James Cloos for suggesting improvements to the fix.)
2299 Changes affecting documentation
2301 tz-link.htm now mentions GNOME.
2304 Release 2014c - 2014-05-13 07:44:13 -0700
2306 Changes affecting near-future timestamps
2308 Egypt observes DST starting 2014-05-15 at 24:00.
2309 (Thanks to Ahmad El-Dardiry and Gunther Vermier.)
2310 Details have not been announced, except that DST will not be observed
2311 during Ramadan. Guess that DST will stop during the same Ramadan dates as
2312 Morocco, and that Egypt's future spring and fall transitions will be the
2313 same as 2010 when it last observed DST, namely April's last Friday at
2314 00:00 to September's last Thursday at 23:00 standard time. Also, guess
2315 that Ramadan transitions will be at 00:00 standard time.
2317 Changes affecting code
2319 zic now generates transitions for minimum time values, eliminating guesswork
2320 when handling low-valued timestamps. (Thanks to Arthur David Olson.)
2322 Port to Cygwin sans glibc. (Thanks to Arthur David Olson.)
2324 Changes affecting commentary and documentation
2326 Remove now-confusing comment about Jordan. (Thanks to Oleksii Nochovnyi.)
2329 Release 2014b - 2014-03-24 21:28:50 -0700
2331 Changes affecting near-future timestamps
2333 Crimea switches to Moscow time on 2014-03-30 at 02:00 local time.
2334 (Thanks to Alexander Krivenyshev.) Move its zone.tab entry from UA to RU.
2336 New entry for Troll station, Antarctica. (Thanks to Paul-Inge Flakstad and
2337 Bengt-Inge Larsson.) This is currently an approximation; a better version
2338 will require the zic and localtime fixes mentioned below, and the plan is
2339 to wait for a while until at least the zic fixes propagate.
2341 Changes affecting code
2343 'zic' and 'localtime' no longer reject locations needing four transitions
2344 per year for the foreseeable future. (Thanks to Andrew Main (Zefram).)
2345 Also, 'zic' avoids some unlikely failures due to integer overflow.
2347 Changes affecting build procedure
2349 'make check' now detects Rule lines defined but never used.
2350 The NZAQ rules, an instance of this problem, have been removed.
2352 Changes affecting commentary and documentation
2354 Fix Tuesday/Thursday typo in description of time in Israel.
2355 (Thanks to Bert Katz via Pavel Kharitonov and Mike Frysinger.)
2357 Microsoft Windows 8.1 doesn't support tz database names. (Thanks
2358 to Donald MacQueen.) Instead, the Microsoft Windows Store app
2359 library supports them.
2361 Add comments about Johnston Island time in the 1960s.
2362 (Thanks to Lyle McElhaney.)
2364 Morocco's 2014 DST start will be as predicted.
2365 (Thanks to Sebastien Willemijns.)
2368 Release 2014a - 2014-03-07 23:30:29 -0800
2370 Changes affecting near-future timestamps
2372 Turkey begins DST on 2014-03-31, not 03-30. (Thanks to Faruk Pasin for
2373 the heads-up, and to Tim Parenti for simplifying the update.)
2375 Changes affecting past timestamps
2377 Fiji ended DST on 2014-01-19 at 02:00, not the previously-scheduled 03:00.
2378 (Thanks to Steffen Thorsen.)
2380 Ukraine switched from Moscow to Eastern European time on 1990-07-01
2381 (not 1992-01-01), and observed DST during the entire next winter.
2382 (Thanks to Vladimir in Moscow via Alois Treindl.)
2384 In 1988 Israel observed DST from 04-10 to 09-04, not 04-09 to 09-03.
2385 (Thanks to Avigdor Finkelstein.)
2387 Changes affecting code
2389 A uninitialized-storage bug in 'localtime' has been fixed.
2390 (Thanks to Logan Chien.)
2392 Changes affecting the build procedure
2394 The settings for 'make check_web' now default to Ubuntu 13.10.
2396 Changes affecting commentary and documentation
2398 The boundary of the US Pacific time zone is given more accurately.
2399 (Thanks to Alan Mintz.)
2401 Chile's 2014 DST will be as predicted. (Thanks to José Miguel Garrido.)
2403 Paraguay's 2014 DST will be as predicted. (Thanks to Carlos Raúl Perasso.)
2405 Better descriptions of countries with same time zone history as
2406 Trinidad and Tobago since 1970. (Thanks to Alan Barrett for suggestion.)
2408 Several changes affect tz-link.htm, the main web page.
2410 Mention Time.is (thanks to Even Scharning) and WX-now (thanks to
2413 Mention xCal (Internet RFC 6321) and jCal.
2415 Microsoft has some support for tz database names.
2417 CLDR data formats include both XML and JSON.
2419 Mention Maggiolo's map of solar vs standard time.
2420 (Thanks to Arthur David Olson.)
2422 Mention TZ4Net. (Thanks to Matt Johnson.)
2424 Mention the timezone-olson Haskell package.
2426 Mention zeitverschiebung.net. (Thanks to Martin Jäger.)
2428 Remove moribund links to daylight-savings-time.info and to
2429 Simple Timer + Clocks.
2431 Update two links. (Thanks to Oscar van Vlijmen.)
2433 Fix some formatting glitches, e.g., remove random newlines from
2434 abbr elements' title attributes.
2437 Release 2013i - 2013-12-17 07:25:23 -0800
2439 Changes affecting near-future timestamps:
2441 Jordan switches back to standard time at 00:00 on December 20, 2013.
2442 The 2006-2011 transition schedule is planned to resume in 2014.
2443 (Thanks to Steffen Thorsen.)
2445 Changes affecting past timestamps:
2447 In 2004, Cuba began DST on March 28, not April 4.
2448 (Thanks to Steffen Thorsen.)
2450 Changes affecting code
2452 The compile-time flag NOSOLAR has been removed, as nowadays the
2453 benefit of slightly shrinking runtime table size is outweighed by the
2454 cost of disallowing potential future updates that exceed old limits.
2456 Changes affecting documentation and commentary
2458 The files solar87, solar88, and solar89 are no longer distributed.
2459 They were a negative experiment - that is, a demonstration that
2460 tz data can represent solar time only with some difficulty and error.
2461 Their presence in the distribution caused confusion, as Riyadh
2462 civil time was generally not solar time in those years.
2464 tz-link.htm now mentions Noda Time. (Thanks to Matt Johnson.)
2467 Release 2013h - 2013-10-25 15:32:32 -0700
2469 Changes affecting current and future timestamps:
2471 Libya has switched its UT offset back to +02 without DST, instead
2472 of +01 with DST. (Thanks to Even Scharning.)
2474 Western Sahara (Africa/El_Aaiun) uses Morocco's DST rules.
2475 (Thanks to Gwillim Law.)
2477 Changes affecting future timestamps:
2479 Acre and (we guess) western Amazonas will switch from UT -04 to -05
2480 on 2013-11-10. This affects America/Rio_Branco and America/Eirunepe.
2481 (Thanks to Steffen Thorsen.)
2483 Add entries for DST transitions in Morocco in the year 2038.
2484 This avoids some year-2038 glitches introduced in 2013g.
2485 (Thanks to Yoshito Umaoka for reporting the problem.)
2487 Changes affecting API
2489 The 'tzselect' command no longer requires the 'select' command,
2490 and should now work with /bin/sh on more platforms. It also works
2491 around a bug in BusyBox awk before version 1.21.0. (Thanks to
2492 Patrick 'P. J.' McDermott and Alan Barrett.)
2494 Changes affecting code
2496 Fix localtime overflow bugs with 32-bit unsigned time_t.
2498 zdump no longer assumes sscanf returns maximal values on overflow.
2500 Changes affecting the build procedure
2502 The builder can specify which programs to use, if any, instead of
2503 'ar' and 'ranlib', and libtz.a is now built locally before being
2504 installed. (Thanks to Michael Forney.)
2506 A dependency typo in the 'zdump' rule has been fixed.
2507 (Thanks to Andrew Paprocki.)
2509 The Makefile has been simplified by assuming that 'mkdir -p' and 'cp -f'
2510 work as specified by POSIX.2-1992 or later; this is portable nowadays.
2512 'make clean' no longer removes 'leapseconds', since it's
2513 host-independent and is part of the distribution.
2515 The unused makefile macros TZCSRCS, TZDSRCS, DATESRCS have been removed.
2517 Changes affecting documentation and commentary
2519 tz-link.htm now mentions TC TIMEZONE's draft time zone service protocol
2520 (thanks to Mike Douglass) and TimezoneJS.Date (thanks to Jim Fehrle).
2522 Update URLs in tz-link page. Add URLs for Microsoft Windows, since
2523 8.1 introduces tz support. Remove URLs for Tru64 and UnixWare (no
2524 longer maintained) and for old advisories. SOFA now does C.
2526 Release 2013g - 2013-09-30 21:08:26 -0700
2528 Changes affecting current and near-future timestamps
2530 Morocco now observes DST from the last Sunday in March to the last
2531 Sunday in October, not April to September respectively. (Thanks
2532 to Steffen Thorsen.)
2534 Changes affecting 'zic'
2536 'zic' now runs on platforms that lack both hard links and symlinks.
2537 (Thanks to Theo Veenker for reporting the problem, for MinGW.)
2538 Also, fix some bugs on platforms that lack hard links but have symlinks.
2540 'zic -v' again warns that Asia/Tehran has no POSIX environment variable
2541 to predict the far future, fixing a bug introduced in 2013e.
2543 Changes affecting the build procedure
2545 The 'leapseconds' file is again put into the tzdata tarball.
2546 Also, 'leapseconds.awk', so tzdata is self-contained. (Thanks to
2547 Matt Burgess and Ian Abbott.) The timestamps of these and other
2548 dependent files in tarballs are adjusted more consistently.
2550 Changes affecting documentation and commentary
2552 The README file is now part of the data tarball as well as the code.
2553 It now states that files are public domain unless otherwise specified.
2554 (Thanks to Andrew Main (Zefram) for asking for clarifications.)
2555 Its details about the 1989 release moved to a place of honor near
2559 Release 2013f - 2013-09-24 23:37:36 -0700
2561 Changes affecting near-future timestamps
2563 Tocantins will very likely not observe DST starting this spring.
2564 (Thanks to Steffen Thorsen.)
2566 Jordan will likely stay at UT +03 indefinitely, and will not fall
2569 Palestine will fall back at 00:00, not 01:00. (Thanks to Steffen Thorsen.)
2571 Changes affecting API
2573 The types of the global variables 'timezone' and 'altzone' (if present)
2574 have been changed back to 'long'. This is required for 'timezone'
2575 by POSIX, and for 'altzone' by common practice, e.g., Solaris 11.
2576 These variables were originally 'long' in the tz code, but were
2577 mistakenly changed to 'time_t' in 1987; nobody reported the
2578 incompatibility until now. The difference matters on x32, where
2579 'long' is 32 bits and 'time_t' is 64. (Thanks to Elliott Hughes.)
2581 Changes affecting the build procedure
2583 Avoid long strings in leapseconds.awk to work around a mawk bug.
2584 (Thanks to Cyril Baurand.)
2586 Changes affecting documentation and commentary
2588 New file 'NEWS' that contains release notes like this one.
2590 Paraguay's law does not specify DST transition time; 00:00 is customary.
2591 (Thanks to Waldemar Villamayor-Venialbo.)
2593 Minor capitalization fixes.
2595 Changes affecting version-control only
2597 The experimental GitHub repository now contains annotated and
2598 signed tags for recent releases, e.g., '2013e' for Release 2013e.
2599 Releases are tagged starting with 2012e; earlier releases were
2600 done differently, and tags would either not have a simple name or
2601 not exactly match what was released.
2603 'make set-timestamps' is now simpler and a bit more portable.
2606 Release 2013e - 2013-09-19 23:50:04 -0700
2608 Changes affecting near-future timestamps
2610 This year Fiji will start DST on October 27, not October 20.
2611 (Thanks to David Wheeler for the heads-up.) For now, guess that
2612 Fiji will continue to spring forward the Sunday before the fourth
2615 Changes affecting current and future time zone abbreviations
2617 Use WIB/WITA/WIT rather than WIT/CIT/EIT for alphabetic Indonesian
2618 time zone abbreviations since 1932. (Thanks to George Ziegler,
2619 Priyadi Iman Nurcahyo, Zakaria, Jason Grimes, Martin Pitt, and
2620 Benny Lin.) This affects Asia/Dili, Asia/Jakarta, Asia/Jayapura,
2621 Asia/Makassar, and Asia/Pontianak.
2623 Use ART (UT -03, standard time), rather than WARST (also -03, but
2624 daylight saving time) for San Luis, Argentina since 2009.
2626 Changes affecting Godthåb timestamps after 2037 if version mismatch
2628 Allow POSIX-like TZ strings where the transition time's hour can
2629 range from -167 through 167, instead of the POSIX-required 0
2630 through 24. E.g., TZ='FJT-12FJST,M10.3.1/146,M1.3.4/75' for the
2631 new Fiji rules. This is a more-compact way to represent
2632 far-future timestamps for America/Godthab, America/Santiago,
2633 Antarctica/Palmer, Asia/Gaza, Asia/Hebron, Asia/Jerusalem,
2634 Pacific/Easter, and Pacific/Fiji. Other zones are unaffected by
2635 this change. (Derived from a suggestion by Arthur David Olson.)
2637 Allow POSIX-like TZ strings where daylight saving time is in
2638 effect all year. E.g., TZ='WART4WARST,J1/0,J365/25' for Western
2639 Argentina Summer Time all year. This supports a more-compact way
2640 to represent the 2013d data for America/Argentina/San_Luis.
2641 Because of the change for San Luis noted above this change does not
2642 affect the current data. (Thanks to Andrew Main (Zefram) for
2643 suggestions that improved this change.)
2645 Where these two TZ changes take effect, there is a minor extension
2646 to the tz file format in that it allows new values for the
2647 embedded TZ-format string, and the tz file format version number
2648 has therefore been increased from 2 to 3 as a precaution.
2649 Version-2-based client code should continue to work as before for
2650 all timestamps before 2038. Existing version-2-based client code
2651 (tzcode, GNU/Linux, Solaris) has been tested on version-3-format
2652 files, and typically works in practice even for timestamps after
2653 2037; the only known exception is America/Godthab.
2655 Changes affecting timestamps before 1970
2657 Pacific/Johnston is now a link to Pacific/Honolulu. This corrects
2658 some errors before 1947.
2660 Some zones have been turned into links, when they differ from existing
2661 zones only in older data entries that were likely invented or that
2662 differ only in LMT or transitions from LMT. These changes affect
2663 only timestamps before 1943. The affected zones are:
2664 Africa/Juba, America/Anguilla, America/Aruba, America/Dominica,
2665 America/Grenada, America/Guadeloupe, America/Marigot,
2666 America/Montserrat, America/St_Barthelemy, America/St_Kitts,
2667 America/St_Lucia, America/St_Thomas, America/St_Vincent,
2668 America/Tortola, and Europe/Vaduz. (Thanks to Alois Treindl for
2669 confirming that the old Europe/Vaduz zone was wrong and the new
2670 link is better for WWII-era times.)
2672 Change Kingston Mean Time from -5:07:12 to -5:07:11. This affects
2673 America/Cayman, America/Jamaica and America/Grand_Turk timestamps
2676 Change the UT offset of Bern Mean Time from 0:29:44 to 0:29:46.
2677 This affects Europe/Zurich timestamps from 1853 to 1894. (Thanks
2680 Change the date of the circa-1850 Zurich transition from 1849-09-12
2681 to 1853-07-16, overriding Shanks with data from Messerli about
2682 postal and telegraph time in Switzerland.
2684 Changes affecting time zone abbreviations before 1970
2686 For Asia/Jakarta, use BMT (not JMT) for mean time from 1923 to 1932,
2687 as Jakarta was called Batavia back then.
2689 Changes affecting API
2691 The 'zic' command now outputs a dummy transition when far-future
2692 data can't be summarized using a TZ string, and uses a 402-year
2693 window rather than a 400-year window. For the current data, this
2694 affects only the Asia/Tehran file. It does not affect any of the
2695 timestamps that this file represents, so zdump outputs the same
2696 information as before. (Thanks to Andrew Main (Zefram).)
2698 The 'date' command has a new '-r' option, which lets you specify
2699 the integer time to display, a la FreeBSD.
2701 The 'tzselect' command has two new options '-c' and '-n', which lets you
2702 select a zone based on latitude and longitude.
2704 The 'zic' command's '-v' option now warns about constructs that
2705 require the new version-3 binary file format. (Thanks to Arthur
2706 David Olson for the suggestion.)
2708 Support for floating-point time_t has been removed.
2709 It was always dicey, and POSIX no longer requires it.
2710 (Thanks to Eric Blake for suggesting to the POSIX committee to
2711 remove it, and thanks to Alan Barrett, Clive D.W. Feather, Andy
2712 Heninger, Arthur David Olson, and Alois Treindl, for reporting
2713 bugs and elucidating some of the corners of the old floating-point
2716 The signatures of 'offtime', 'timeoff', and 'gtime' have been
2717 changed back to the old practice of using 'long' to represent UT
2718 offsets. This had been inadvertently and mistakenly changed to
2719 'int_fast32_t'. (Thanks to Christos Zoulas.)
2721 The code avoids undefined behavior on integer overflow in some
2722 more places, including gmtime, localtime, mktime and zdump.
2724 Changes affecting the zdump utility
2726 zdump now outputs "UT" when referring to Universal Time, not "UTC".
2727 "UTC" does not make sense for timestamps that predate the introduction
2728 of UTC, whereas "UT", a more-generic term, does. (Thanks to Steve Allen
2729 for clarifying UT vs UTC.)
2731 Data changes affecting behavior of tzselect and similar programs
2733 Country code BQ is now called the more-common name "Caribbean Netherlands"
2734 rather than the more-official "Bonaire, St Eustatius & Saba".
2736 Remove from zone.tab the names America/Montreal, America/Shiprock,
2737 and Antarctica/South_Pole, as they are equivalent to existing
2738 same-country-code zones for post-1970 timestamps. The data entries for
2739 these names are unchanged, so the names continue to work as before.
2741 Changes affecting code internals
2743 zic -c now runs way faster on 64-bit hosts when given large numbers.
2745 zic now uses vfprintf to avoid allocating and freeing some memory.
2747 tzselect now computes the list of continents from the data,
2748 rather than have it hard-coded.
2750 Minor changes pacify GCC 4.7.3 and GCC 4.8.1.
2752 Changes affecting the build procedure
2754 The 'leapseconds' file is now generated automatically from a
2755 new file 'leap-seconds.list', which is a copy of
2756 <ftp://ftp.nist.gov/pub/time/leap-seconds.list>
2757 A new source file 'leapseconds.awk' implements this.
2758 The goal is simplification of the future maintenance of 'leapseconds'.
2760 When building the 'posix' or 'right' subdirectories, if the
2761 subdirectory would be a copy of the default subdirectory, it is
2762 now made a symbolic link if that is supported. This saves about
2763 2 MB of file system space.
2765 The links America/Shiprock and Antarctica/South_Pole have been
2766 moved to the 'backward' file. This affects only nondefault builds
2767 that omit 'backward'.
2769 Changes affecting version-control only
2771 .gitignore now ignores 'date'.
2773 Changes affecting documentation and commentary
2775 Changes to the 'tzfile' man page
2777 It now mentions that the binary file format may be extended in
2778 future versions by appending data.
2780 It now refers to the 'zdump' and 'zic' man pages.
2782 Changes to the 'zic' man page
2784 It lists conditions that elicit a warning with '-v'.
2786 It says that the behavior is unspecified when duplicate names
2787 are given, or if the source of one link is the target of another.
2789 Its examples are updated to match the latest data.
2791 The definition of white space has been clarified slightly.
2792 (Thanks to Michael Deckers.)
2794 Changes to the 'Theory' file
2796 There is a new section about the accuracy of the tz database,
2797 describing the many ways that errors can creep in, and
2798 explaining why so many of the pre-1970 timestamps are wrong or
2799 misleading (thanks to Steve Allen, Lester Caine, and Garrett
2800 Wollman for discussions that contributed to this).
2802 The 'Theory' file describes LMT better (this follows a
2803 suggestion by Guy Harris).
2805 It refers to the 2013 edition of POSIX rather than the 2004 edition.
2807 It's mentioned that excluding 'backward' should not affect the
2808 other data, and it suggests at least one zone.tab name per
2809 inhabited country (thanks to Stephen Colebourne).
2811 Some longstanding restrictions on names are documented, e.g.,
2812 'America/New_York' precludes 'America/New_York/Bronx'.
2814 It gives more reasons for the 1970 cutoff.
2816 It now mentions which time_t variants are supported, such as
2817 signed integer time_t. (Thanks to Paul Goyette for reporting
2818 typos in an experimental version of this change.)
2820 (Thanks to Philip Newton for correcting typos in these changes.)
2822 Documentation and commentary is more careful to distinguish UT in
2823 general from UTC in particular. (Thanks to Steve Allen.)
2825 Add a better source for the Zurich 1894 transition.
2826 (Thanks to Pierre-Yves Berger.)
2828 Update shapefile citations in tz-link.htm. (Thanks to Guy Harris.)
2831 Release 2013d - 2013-07-05 07:38:01 -0700
2833 Changes affecting future timestamps:
2835 Morocco's midsummer transitions this year are July 7 and August 10,
2836 not July 9 and August 8. (Thanks to Andrew Paprocki.)
2838 Israel now falls back on the last Sunday of October.
2839 (Thanks to Ephraim Silverberg.)
2841 Changes affecting past timestamps:
2843 Specify Jerusalem's location more precisely; this changes the pre-1880
2846 Changing affecting metadata only:
2848 Fix typos in the entries for country codes BQ and SX.
2850 Changes affecting code:
2852 Rework the code to fix a bug with handling Australia/Macquarie on
2853 32-bit hosts (thanks to Arthur David Olson).
2855 Port to platforms like NetBSD, where time_t can be wider than long.
2857 Add support for testing time_t types other than the system's.
2858 Run 'make check_time_t_alternatives' to try this out.
2859 Currently, the tests fail for unsigned time_t;
2860 this should get fixed at some point.
2862 Changes affecting documentation and commentary:
2864 Deemphasize the significance of national borders.
2866 Update the zdump man page.
2868 Remove obsolete NOID comment (thanks to Denis Excoffier).
2870 Update several URLs and comments in the web pages.
2872 Spelling fixes (thanks to Kevin Lyda and Jonathan Leffler).
2874 Update URL for CLDR Zone->Tzid table (thanks to Yoshito Umaoka).
2877 Release 2013c - 2013-04-19 16:17:40 -0700
2879 Changes affecting current and future timestamps:
2881 Palestine observed DST starting March 29, 2013. (Thanks to
2882 Steffen Thorsen.) From 2013 on, Gaza and Hebron both observe DST,
2883 with the predicted rules being the last Thursday in March at 24:00
2884 to the first Friday on or after September 21 at 01:00.
2886 Assume that the recent change to Paraguay's DST rules is permanent,
2887 by moving the end of DST to the 4th Sunday in March every year.
2888 (Thanks to Carlos Raúl Perasso.)
2890 Changes affecting past timestamps:
2892 Fix some historical data for Palestine to agree with that of
2893 timeanddate.com, as follows:
2895 The spring 2008 change in Gaza and Hebron was on 00:00 Mar 28, not
2898 The fall 2009 change in Gaza and Hebron on Sep 4 was at 01:00, not
2901 The spring 2010 change in Hebron was 00:00 Mar 26, not 00:01 Mar 27.
2903 The spring 2011 change in Gaza was 00:01 Apr 1, not 12:01 Apr 2.
2905 The spring 2011 change in Hebron on Apr 1 was at 00:01, not 12:01.
2907 The fall 2011 change in Hebron on Sep 30 was at 00:00, not 03:00.
2909 Fix times of habitation for Macquarie to agree with the Tasmania
2910 Parks & Wildlife Service history, which indicates that permanent
2911 habitation was 1899-1919 and 1948 on.
2913 Changing affecting metadata only:
2915 Macquarie Island is politically part of Australia, not Antarctica.
2916 (Thanks to Tobias Conradi.)
2918 Sort Macquarie more-consistently with other parts of Australia.
2919 (Thanks to Tim Parenti.)
2922 Release 2013b - 2013-03-10 22:33:40 -0700
2924 Changes affecting current and future timestamps:
2926 Haiti uses US daylight-saving rules this year, and presumably future years.
2927 This changes timestamps starting today. (Thanks to Steffen Thorsen.)
2929 Paraguay will end DST on March 24 this year.
2930 (Thanks to Steffen Thorsen.) For now, assume it's just this year.
2932 Morocco does not observe DST during Ramadan;
2933 try to predict Ramadan in Morocco as best we can.
2934 (Thanks to Erik Homoet for the heads-up.)
2936 Changes affecting commentary:
2938 Update URLs in tz-link page. Add URLs for webOS, BB10, iOS.
2939 Update URL for Solaris. Mention Internet RFC 6557.
2940 Update Internet RFCs 2445->5545, 2822->5322.
2941 Switch from FTP to HTTP for Internet RFCs.
2944 Release 2013a - 2013-02-27 09:20:35 -0800
2946 Change affecting binary data format:
2948 The zone offset at the end of version-2-format zone files is now
2949 allowed to be 24:00, as per POSIX.1-2008. (Thanks to Arthur David Olson.)
2951 Changes affecting current and future timestamps:
2953 Chile's 2013 rules, and we guess rules for 2014 and later, will be
2954 the same as 2012, namely Apr Sun>=23 03:00 UTC to Sep Sun>=2 04:00 UTC.
2955 (Thanks to Steffen Thorsen and Robert Elz.)
2957 New Zones Asia/Khandyga, Asia/Ust-Nera, Europe/Busingen.
2958 (Thanks to Tobias Conradi and Arthur David Olson.)
2960 Many changes affect historical timestamps before 1940.
2961 These were deduced from: Milne J. Civil time. Geogr J. 1899
2962 Feb;13(2):173-94 <https://www.jstor.org/stable/1774359>.
2964 Changes affecting the code:
2966 Fix zic bug that mishandled Egypt's 2010 changes (this also affected
2967 the data). (Thanks to Arthur David Olson.)
2969 Fix localtime bug when time_t is unsigned and data files were generated
2970 by a signed time_t system. (Thanks to Doug Bailey for reporting and
2971 to Arthur David Olson for fixing.)
2973 Allow the email address for bug reports to be set by the packager.
2974 The default is tz@iana.org, as before. (Thanks to Joseph S. Myers.)
2976 Update HTML checking to be compatible with Ubuntu 12.10.
2978 Check that files are a safe subset of ASCII. At some point we may
2979 relax this requirement to a safe subset of UTF-8. Without the
2980 check, some non-UTF-8 encodings were leaking into the distribution.
2984 Restore a comment about copyright notices that was inadvertently deleted.
2985 (Thanks to Arthur David Olson.)
2987 Improve the commentary about which districts observe what times
2988 in Russia. (Thanks to Oscar van Vlijmen and Arthur David Olson).
2990 Add web page links to tz.js.
2992 Add "Run by the Monkeys" to tz-art. (Thanks to Arthur David Olson.)
2995 Release 2012j - 2012-11-12 18:34:49 -0800
2997 Libya moved to CET this weekend, but with DST planned next year.
2998 (Thanks to Even Scharning, Steffen Thorsen, and Tim Parenti.)
3000 Signatures now have the extension .asc, not .sign, as that's more
3001 standard. (Thanks to Phil Pennock.)
3003 The output of 'zdump --version', and of 'zic --version', now
3004 uses a format that is more typical for --version.
3005 (Thanks to Joseph S. Myers.)
3007 The output of 'tzselect --help', 'zdump --help', and 'zic --help'
3008 now uses tz@iana.org rather than the old elsie address.
3010 zic -v now complains about abbreviations that are less than 3
3011 or more than 6 characters, as per Posix. Formerly, it checked
3012 for abbreviations that were more than 3.
3014 'make public' no longer puts its temporary directory under /tmp,
3015 and uses the just-built zic rather than the system zic.
3017 Various fixes to documentation and commentary.
3020 Release 2012i - 2012-11-03 12:57:09 -0700
3022 Cuba switches from DST tomorrow at 01:00. (Thanks to Steffen Thorsen.)
3024 Linker flags can now be specified via LDFLAGS.
3025 AWK now defaults to 'awk', not 'nawk'.
3026 The shell in tzselect now defaults to /bin/bash, but this can
3027 be overridden by specifying KSHELL.
3028 The main web page now mentions the unofficial GitHub repository.
3029 (Thanks to Mike Frysinger.)
3031 Tarball signatures can now be built by running 'make signatures'.
3032 There are also new makefile rules 'tarballs', 'check_public', and
3033 separate makefile rules for each tarball and signature file.
3034 A few makefile rules are now more portable to strict POSIX.
3036 The main web page now lists the canonical IANA URL.
3039 Release 2012h - 2012-10-26 22:49:10 -0700
3041 Bahia no longer has DST. (Thanks to Kelley Cook.)
3043 Tocantins has DST. (Thanks to Rodrigo Severo.)
3045 Israel has new DST rules next year. (Thanks to Ephraim Silverberg.)
3047 Jordan stays on DST this winter. (Thanks to Steffen Thorsen.)
3051 More C modernization, except that at Arthur David Olson's suggestion
3052 the instances of 'register' were kept.
3055 Release 2012g - 2012-10-17 20:59:45 -0700
3057 Samoa fall 2012 and later. (Thanks to Nicholas Pereira and Robert Elz.)
3059 Palestine fall 2012. (Thanks to Steffen Thorsen.)
3063 To attack the version-number problem, this release ships the file
3064 'Makefile' (which contains the release number) in both the tzcode and
3065 the tzdata tarballs. The two Makefiles are identical, and should be
3066 identical in any matching pair of tarballs, so it shouldn't matter
3067 which order you extract the tarballs. Perhaps we can come up with a
3068 better version-number scheme at some point; this scheme does have the
3069 virtue of not adding more files.
3072 Release 2012f - 2012-09-12 23:17:03 -0700
3074 * australasia (Pacific/Fiji): Fiji DST is October 21 through January
3075 20 this year. (Thanks to Steffen Thorsen.)
3078 Release 2012e - 2012-08-02 20:44:55 -0700
3080 * australasia (Pacific/Fakaofo): Tokelau is UT +13, not +14.
3081 (Thanks to Steffen Thorsen.)
3083 * Use a single version number for both code and data.
3085 * .gitignore: New file.
3087 * Remove trailing white space.
3090 Release code2012c-data2012d - 2012-07-19 16:35:33 -0700
3092 Changes for Morocco's timestamps, which take effect in a couple of
3093 hours, along with infrastructure changes to accommodate how the tz
3094 code and data are released on IANA.
3097 Release data2012c - 2012-03-27 12:17:25 -0400
3100 Summer time changes for Morocco (to start late April 2012)
3103 Changes for 2012 for Gaza & the West Bank (Hebron) and Syria
3106 Haiti following US/Canada rules for 2012 (and we're assuming,
3107 for now anyway, for the future).
3110 Release 2012b - 2012-03-02 12:29:15 +0700
3112 There is just one change to tzcode2012b (compared with 2012a):
3113 the Makefile that was accidentally included with 2012a has been
3114 replaced with the version that should have been there, which is
3115 identical with the previous version (from tzcode2011i).
3117 There are just two changes in tzdata2012b compared with 2012a.
3119 Most significantly, summer time in Cuba has been delayed 3 weeks
3120 (now starts April 1 rather than March 11). Since Mar 11 (the old start
3121 date, as listed in 2012a) is just a little over a week away, this
3124 Less importantly, an excess tab in one of the changes in zone.tab
3125 in 2012a has been removed.
3128 Release 2012a - 2012-03-01 18:28:10 +0700
3130 The changes in tzcode2012a (compared to the previous version, 2011i)
3131 are entirely to the README and tz-art.htm and tz-link.htm files, if
3132 none of those concern you, you can ignore the code update. The changes
3133 reflect the changed addresses for the mailing list and the code and
3134 data distribution points & methods (and a link to DateTime::TimeZone::Tzfile
3135 has been added to tz-link.htm).
3137 In tzdata2012a (compared to the previous release, which was 2011n)
3138 the major changes are:
3139 Chile 2011/2012 and 2012/2013 summer time date adjustments.
3140 Falkland Islands onto permanent summer time (we're assuming for the
3141 foreseeable future, though 2012 is all we're fairly certain of.)
3142 Armenia has abolished Summer Time.
3143 Tokelau jumped the International Date Line back last December
3144 (just the same as their near neighbour, Samoa).
3145 America/Creston is a new zone for a small area of British Columbia
3146 There will be a leapsecond 2012-06-30 23:59:60 UTC.
3148 Other minor changes are:
3149 Corrections to 1918 Canadian summer time end dates.
3150 Updated URL for UK time zone history (in comments)
3151 A few typos in Le Corre's list of free French place names (comments)
3154 Release data2011n - 2011-10-30 14:57:54 +0700
3156 There are three changes of note - most urgently, Cuba (America/Havana)
3157 has extended summer time by two weeks, now to end on Nov 13, rather than
3158 the (already past) Oct 30. Second, the Pridnestrovian Moldavian Republic
3159 (Europe/Tiraspol) decided not to split from the rest of Moldova after
3160 all, and consequently that zone has been removed (again) and reinstated
3161 in the "backward" file as a link to Europe/Chisinau. And third, the
3162 end date for Fiji's summer time this summer was moved forward from the
3163 earlier planned Feb 26, to Jan 22.
3165 Apart from that, Moldova (MD) returns to a single entry in zone.tab
3166 (and the incorrect syntax that was in the 2011m version of that file
3167 is so fixed - it would have been fixed in a different way had this
3168 change not happened - that's the "missing" sccs version id).
3171 Release data2011m - 2011-10-24 21:42:16 +0700
3173 In particular, the typos in comments in the data (2011-11-17 should have
3174 been 2011-10-17 as Alan Barrett noted, and spelling of Tiraspol that
3175 Tim Parenti noted) have been fixed, and the change for Ukraine has been
3176 made in all 4 Ukrainian zones, rather than just Kiev (again, thanks to
3177 Tim Parenti, and also Denys Gavrysh)
3179 In addition, I added Europe/Tiraspol to zone.tab.
3181 This time, all the files have new version numbers... (including the files
3182 otherwise unchanged in 2011m that were changed in 2011l but didn't get new
3183 version numbers there...)
3186 Release data2011l - 2011-10-10 11:15:43 +0700
3188 There are just 2 changes that cause different generated tzdata files from
3189 zic, to Asia/Hebron and Pacific/Fiji - the possible change for Bahia, Brazil
3190 is included, but commented out. Compared with the diff I sent out last week,
3191 this version also includes attributions for the sources for the changes
3192 (in much the same format as ado used, but the html tags have not been
3193 checked, verified, or used in any way at all, so if there are errors there,
3194 please let me know.)
3197 Release data2011k - 2011-09-20 17:54:03 -0400
3202 Release data2011j - 2011-09-12 09:22:49 -0400
3204 (contemporary changes for Samoa; past changes for Kenya, Uganda, and
3205 Tanzania); there are also two spelling corrections to comments in
3206 the australasia file (with thanks to Christos Zoulas).
3209 Release 2011i - 2011-08-29 05:56:32 -0400
3214 Release data2011h - 2011-06-15 18:41:48 -0400
3216 Russia and Curaçao changes
3219 Release 2011g - 2011-04-25 09:07:22 -0400
3221 update the rules for Egypt to reflect its abandonment of DST this year
3224 Release 2011f - 2011-04-06 17:14:53 -0400
3229 Release 2011e - 2011-03-31 16:04:38 -0400
3231 Morocco, Chile, and tz-link changes
3234 Release 2011d - 2011-03-14 09:18:01 -0400
3236 changes that impact present-day timestamps in Cuba, Samoa, and Turkey
3239 Release 2011c - 2011-03-07 09:30:09 -0500
3241 These do affect current timestamps in Chile and Annette Island, Canada.
3244 Release 2011b - 2011-02-07 08:44:50 -0500
3249 Release 2011a - 2011-01-24 10:30:16 -0500
3254 Release data2010o - 2010-11-01 09:18:23 -0400
3256 change to the end of DST in Fiji in 2011
3259 Release 2010n - 2010-10-25 08:19:17 -0400
3264 Release 2010m - 2010-09-27 09:24:48 -0400
3266 Hong Kong, Vostok, and zic.c changes
3269 Release 2010l - 2010-08-16 06:57:25 -0400
3274 Release 2010k - 2010-07-26 10:42:27 -0400
3279 Release 2010j - 2010-05-10 09:07:48 -0400
3281 changes for Bahía de Banderas and for version naming
3284 Release data2010i - 2010-04-16 18:50:45 -0400
3286 the end of DST in Morocco on 2010-08-08
3289 Release data2010h - 2010-04-05 09:58:56 -0400
3294 Release data2010g - 2010-03-24 11:14:53 -0400
3299 Release 2010f - 2010-03-22 09:45:46 -0400
3304 Release data2010e - 2010-03-08 14:24:27 -0500
3306 corrects the Dhaka bug found by Danvin Ruangchan
3309 Release data2010d - 2010-03-06 07:26:01 -0500
3314 Release 2010c - 2010-03-01 09:20:58 -0500
3316 changes including KRE's suggestion for earlier initialization of
3317 "goahead" and "goback" structure elements
3320 Release code2010a - 2010-02-16 10:40:04 -0500
3325 Release data2010b - 2010-01-20 12:37:01 -0500
3330 Release data2010a - 2010-01-18 08:30:04 -0500
3335 Release data2009u - 2009-12-26 08:32:28 -0500
3337 changes to DST in Bangladesh
3340 Release 2009t - 2009-12-21 13:24:27 -0500
3345 Release data2009s - 2009-11-14 10:26:32 -0500
3347 (cosmetic) Antarctica change and the DST-in-Fiji-in-2009-and-2010 change
3350 Release 2009r - 2009-11-09 10:10:31 -0500
3352 "antarctica" and "tz-link.htm" changes
3355 Release 2009q - 2009-11-02 09:12:40 -0500
3357 with two corrections as reported by Eric Muller and Philip Newton
3360 Release data2009p - 2009-10-23 15:05:27 -0400
3362 Argentina (including San Luis) changes (with the correction from
3366 Release data2009o - 2009-10-14 16:49:38 -0400
3368 Samoa (commentary only), Pakistan, and Bangladesh changes
3371 Release data2009n - 2009-09-22 15:13:38 -0400
3373 added commentary for Argentina and a change to the end of DST in
3377 Release data2009m - 2009-09-03 10:23:43 -0400
3379 Samoa and Palestine changes
3382 Release data2009l - 2009-08-14 09:13:07 -0400
3384 Samoa (comments only) and Egypt
3387 Release 2009k - 2009-07-20 09:46:08 -0400
3392 Release data2009j - 2009-06-15 06:43:59 -0400
3394 Bangladesh change (with a short turnaround since the DST change is
3398 Release 2009i - 2009-06-08 09:21:22 -0400
3400 updating for DST in Bangladesh this year
3403 Release 2009h - 2009-05-26 09:19:14 -0400
3408 Release data2009g - 2009-04-20 16:34:07 -0400
3413 Release data2009f - 2009-04-10 11:00:52 -0400
3415 correct DST in Pakistan
3418 Release 2009e - 2009-04-06 09:08:11 -0400
3423 Release 2009d - 2009-03-23 09:38:12 -0400
3425 Morocco, Tunisia, Argentina, and American Astronomical Society changes
3428 Release data2009c - 2009-03-16 09:47:51 -0400
3430 change to the start of Cuban DST
3433 Release 2009b - 2009-02-09 11:15:22 -0500
3438 Release 2009a - 2009-01-21 10:09:39 -0500
3443 Release data2008i - 2008-10-21 12:10:25 -0400
3445 southamerica and zone.tab files, with Argentina DST rule changes and
3446 United States zone reordering and recommenting
3449 Release 2008h - 2008-10-13 07:33:56 -0400
3454 Release 2008g - 2008-10-06 09:03:18 -0400
3456 Fix a broken HTML anchor and update Brazil's DST transitions;
3457 there's also a slight reordering of information in tz-art.htm.
3460 Release data2008f - 2008-09-09 22:33:26 -0400
3465 Release 2008e - 2008-07-28 14:11:17 -0400
3467 changes by Arthur David Olson and Jesper Nørgaard Welen
3470 Release data2008d - 2008-07-07 09:51:38 -0400
3472 changes by Arthur David Olson, Paul Eggert, and Rodrigo Severo
3475 Release data2008c - 2008-05-19 17:48:03 -0400
3477 Pakistan, Morocco, and Mongolia
3480 Release data2008b - 2008-03-24 08:30:59 -0400
3482 including renaming Asia/Calcutta to Asia/Kolkata, with a backward
3486 Release 2008a - 2008-03-08 05:42:16 -0500
3491 Release 2007k - 2007-12-31 10:25:22 -0500
3493 most importantly, changes to the "southamerica" file based on
3494 Argentina's readoption of daylight saving time
3497 Release 2007j - 2007-12-03 09:51:01 -0500
3499 1. eliminate the "P" (parameter) macro;
3501 2. the "noncontroversial" changes circulated on the time zone
3502 mailing list (less the changes to "logwtmp.c");
3504 3. eliminate "too many transition" errors when "min" is used in time
3507 4. changes by Paul Eggert (including updated information for Venezuela).
3510 Release data2007i - 2007-10-30 10:28:11 -0400
3512 changes for Cuba and Syria
3515 Release 2007h - 2007-10-01 10:05:51 -0400
3517 changes by Paul Eggert, as well as an updated link to the ICU
3518 project in tz-link.htm
3521 Release 2007g - 2007-08-20 10:47:59 -0400
3523 changes by Paul Eggert
3525 The "leapseconds" file has been updated to incorporate the most
3526 recent International Earth Rotation and Reference Systems Service
3529 There's an addition to tz-art.htm regarding the television show "Medium".
3532 Release 2007f - 2007-05-07 10:46:46 -0400
3534 changes by Paul Eggert (including Haiti, Turks and Caicos, and New
3537 changes to zic.c to allow hour values greater than 24 (along with
3538 Paul's improved time value overflow checking)
3541 Release 2007e - 2007-04-02 10:11:52 -0400
3543 Syria and Honduras changes by Paul Eggert
3545 zic.c variable renaming changes by Arthur David Olson
3548 Release 2007d - 2007-03-20 08:48:30 -0400
3550 changes by Paul Eggert
3552 the elimination of white space at the ends of lines
3555 Release 2007c - 2007-02-26 09:09:37 -0500
3557 changes by Paul Eggert
3560 Release 2007b - 2007-02-12 09:34:20 -0500
3562 Paul Eggert's proposed change to the quotation handling logic in zic.c.
3564 changes to the commentary in "leapseconds" reflecting the IERS
3565 announcement that there is to be no positive leap second at the end
3569 Release 2007a - 2007-01-08 12:28:29 -0500
3571 changes by Paul Eggert
3573 Derick Rethan's Asmara change
3575 Oscar van Vlijmen's Easter Island local mean time change
3577 symbolic link changes
3580 Release 2006p - 2006-11-27 08:54:27 -0500
3582 changes by Paul Eggert
3585 Release 2006o - 2006-11-06 09:18:07 -0500
3587 changes by Paul Eggert
3590 Release 2006n - 2006-10-10 11:32:06 -0400
3592 changes by Paul Eggert
3595 Release 2006m - 2006-10-02 15:32:35 -0400
3597 changes for Uruguay, Palestine, and Egypt by Paul Eggert
3599 (minimalist) changes to zic.8 to clarify "until" information
3602 Release data2006l - 2006-09-18 12:58:11 -0400
3604 Paul's best-effort work on this coming weekend's Egypt time change
3607 Release 2006k - 2006-08-28 12:19:09 -0400
3609 changes by Paul Eggert
3612 Release 2006j - 2006-08-21 09:56:32 -0400
3614 changes by Paul Eggert
3617 Release code2006i - 2006-08-07 12:30:55 -0400
3621 Ken Pizzini's conversion script
3624 Release code2006h - 2006-07-24 09:19:37 -0400
3626 adds public domain notices to four files
3628 includes a fix for transition times being off by a second
3630 adds a new recording to the "arts" file (information courtesy Colin Bowern)
3633 Release 2006g - 2006-05-08 17:18:09 -0400
3635 northamerica changes by Paul Eggert
3638 Release 2006f - 2006-05-01 11:46:00 -0400
3640 a missing version number problem is fixed (with thanks to Bradley
3641 White for catching the problem)
3644 Release 2006d - 2006-04-17 14:33:43 -0400
3646 changes by Paul Eggert
3648 added new items to tz-arts.htm that were found by Paul
3651 Release 2006c - 2006-04-03 10:09:32 -0400
3653 two sets of data changes by Paul Eggert
3655 a fencepost error fix in zic.c
3657 changes to zic.c and the "europe" file to minimize differences
3658 between output produced by the old 32-bit zic and the new 64-bit
3662 Release 2006b - 2006-02-20 10:08:18 -0500
3663 [tz32code2006b + tz64code2006b + tzdata2006b]
3667 All SCCS IDs were bumped to "8.1" for this release.
3670 Release 2006a - 2006-01-30 08:59:31 -0500
3672 changes by Paul Eggert (in particular, Indiana time zone moves)
3674 an addition to the zic manual page to describe how special-case
3675 transitions are handled
3678 Release 2005r - 2005-12-27 09:27:13 -0500
3680 Canadian changes by Paul Eggert
3682 They also add "<pre>" directives to time zone data files and reflect
3683 changes to warning message logic in "zdump.c" (but with calls to
3684 "gettext" kept unbundled at the suggestion of Ken Pizzini).
3687 Release 2005q - 2005-12-13 09:17:09 -0500
3689 Nothing earth-shaking here:
3690 1. Electronic mail addresses have been removed.
3691 2. Casts of the return value of exit have been removed.
3692 3. Casts of the argument of is.* macros have been added.
3693 4. Indentation in one section of zic.c has been fixed.
3694 5. References to dead URLs in the data files have been dealt with.
3697 Release 2005p - 2005-12-05 10:30:53 -0500
3699 "systemv", "tz-link.htm", and "zdump.c" changes
3700 (less the casts of arguments to the is* macros)
3703 Release 2005o - 2005-11-28 10:55:26 -0500
3705 Georgia, Cuba, Nicaragua, and Jordan changes by Paul Eggert
3707 zdump.c lint fixes by Arthur David Olson
3710 Release 2005n - 2005-10-03 09:44:09 -0400
3712 changes by Paul Eggert (both the Uruguay changes and the Kyrgyzstan
3716 Release 2005m - 2005-08-29 12:15:40 -0400
3718 changes by Paul Eggert (with a small tweak to the tz-art change)
3720 a declaration of an unused variable has been removed from zdump.c
3723 Release 2005l - 2005-08-22 12:06:39 -0400
3725 changes by Paul Eggert
3727 overflow/underflow checks by Arthur David Olson, minus changes to
3728 the "Theory" file about the pending addition of 64-bit data (I grow
3729 less confident of the changes being accepted with each passing day,
3730 and the changes no longer increase the data files nine-fold--there's
3731 less than a doubling in size by my local Sun's reckoning)
3734 Release 2005k - 2005-07-14 14:14:24 -0400
3736 The "leapseconds" file has been edited to reflect the recently
3737 announced leap second at the end of 2005.
3739 I've also deleted electronic mail addresses from the files as an
3743 Release 2005j - 2005-06-13 14:34:13 -0400
3745 These reflect changes to limit the length of time zone abbreviations
3746 and the characters used in those abbreviations.
3748 There are also changes to handle POSIX-style "quoted" timezone
3749 environment variables.
3751 The changes were circulated on the time zone mailing list; the only
3752 change since then was the removal of a couple of minimum-length of
3753 abbreviation checks.
3756 Release data2005i - 2005-04-21 15:04:16 -0400
3758 changes (most importantly to Nicaragua and Haiti) by Paul Eggert
3761 Release 2005h - 2005-04-04 11:24:47 -0400
3763 changes by Paul Eggert
3765 minor changes to Makefile and zdump.c to produce more useful output
3766 when doing a "make typecheck"
3769 Release 2005g - 2005-03-14 10:11:21 -0500
3771 changes by Paul Eggert (a change to current DST rules in Uruguay and
3772 an update to a link to time zone software)
3775 Release 2005f - 2005-03-01 08:45:32 -0500
3777 data and documentation changes by Paul Eggert
3780 Release 2005e - 2005-02-10 15:59:44 -0500
3785 Release code2005d - 2005-01-31 09:21:47 -0500
3787 make zic complain about links to links if the -v flag is used
3789 have "make public" do more code checking
3791 add an include to "localtime.c" for the benefit of gcc systems
3794 Release 2005c - 2005-01-17 18:36:29 -0500
3796 get better results when mktime runs on a system where time_t is double
3798 changes to the data files (most importantly to Paraguay)
3801 Release 2005b - 2005-01-10 09:19:54 -0500
3803 Get localtime and gmtime working on systems with exotic time_t types.
3805 Update the leap second commentary in the "leapseconds" file.
3808 Release 2005a - 2005-01-01 13:13:44 -0500
3813 Release code2004i - 2004-12-14 13:42:58 -0500
3815 Deal with systems where time_t is unsigned.
3818 Release code2004h - 2004-12-07 11:40:18 -0500
3820 64-bit-time_t changes
3823 Release 2004g - 2004-11-02 09:06:01 -0500
3825 update to Cuba (taking effect this weekend)
3827 other changes by Paul Eggert
3829 correction of the spelling of Oslo
3831 changed versions of difftime.c and private.h
3834 Release code2004f - 2004-10-21 10:25:22 -0400
3836 Cope with wide-ranging tm_year values.
3839 Release 2004e - 2004-10-11 14:47:21 -0400
3841 Brazil/Argentina/Israel changes by Paul Eggert
3843 changes to tz-link.htm by Paul
3845 one small fix to Makefile
3848 Release 2004d - 2004-09-22 08:27:29 -0400
3850 Avoid overflow problems when TM_YEAR_BASE is added to an integer.
3853 Release 2004c - 2004-08-11 12:06:26 -0400
3855 asctime-related changes
3857 (variants of) some of the documentation changes suggested by Paul Eggert
3860 Release 2004b - 2004-07-19 14:33:35 -0400
3862 data changes by Paul Eggert - most importantly, updates for Argentina
3865 Release 2004a - 2004-05-27 12:00:47 -0400
3867 changes by Paul Eggert
3869 Handle DST transitions that occur at the end of a month in some
3870 years but at the start of the following month in other years.
3872 Add a copy of the correspondence that's the basis for claims about
3873 DST in the Navajo Nation.
3876 Release 2003e - 2003-12-15 09:36:47 -0500
3878 changes by Arthur David Olson (primarily code changes)
3880 changes by Paul Eggert (primarily data changes)
3882 minor changes to "Makefile" and "northamerica" (in the latter case,
3883 optimization of the "Toronto" rules)
3886 Release 2003d - 2003-10-06 09:34:44 -0400
3888 changes by Paul Eggert
3891 Release 2003c - 2003-09-16 10:47:05 -0400
3893 Fix bad returns in zic.c's inleap function.
3894 Thanks to Bradley White for catching the problem!
3897 Release 2003b - 2003-09-16 07:13:44 -0400
3899 Add a "--version" option (and documentation) to the zic and zdump commands.
3901 changes to overflow/underflow checking in zic
3903 a localtime typo fix.
3905 Update the leapseconds and tz-art.htm files.
3908 Release 2003a - 2003-03-24 09:30:54 -0500
3910 changes by Paul Eggert
3912 a few additions and modifications to the tz-art.htm file
3915 Release 2002d - 2002-10-15 13:12:42 -0400
3917 changes by Paul Eggert, less the "Britain (UK)" change in iso3166.tab
3919 There's also a new time zone quote in "tz-art.htm".
3922 Release 2002c - 2002-04-04 11:55:20 -0500
3924 changes by Paul Eggert
3926 Change zic.c to avoid creating symlinks to files that don't exist.
3929 Release 2002b - 2002-01-28 12:56:03 -0500
3931 [These change notes are for Release 2002a, which was corrupted.
3932 2002b was a corrected version of 2002a.]
3934 changes by Paul Eggert
3936 Update the "leapseconds" file to note that there'll be no leap
3937 second at the end of June, 2002.
3939 Change "zic.c" to deal with a problem in handling the "Asia/Bishkek" zone.
3941 Change to "difftime.c" to avoid sizeof problems.
3944 Release 2001d - 2001-10-09 13:31:32 -0400
3946 changes by Paul Eggert
3949 Release 2001c - 2001-06-05 13:59:55 -0400
3951 changes by Paul Eggert and Andrew Brown
3954 Release 2001b - 2001-04-05 16:44:38 -0400
3956 changes by Paul Eggert (modulo jnorgard's typo fix)
3958 tz-art.htm has been HTMLified.
3961 Release 2001a - 2001-03-13 12:57:44 -0500
3963 changes by Paul Eggert
3965 An addition to the "leapseconds" file: comments with the text of the
3966 latest IERS leap second notice.
3968 Trailing white space has been removed from data file lines, and
3969 repeated spaces in "Rule Jordan" lines in the "asia" file have been
3973 Release 2000h - 2000-12-14 15:33:38 -0500
3975 changes by Paul Eggert
3977 one typo fix in the "art" file
3979 With providence, this is the last update of the millennium.
3982 Release 2000g - 2000-10-10 11:35:22 -0400
3984 changes by Paul Eggert
3986 correction of John Mackin's name submitted by Robert Elz
3988 Garry Shandling's Daylight Saving Time joke (!?!) from the recent
3989 Emmy Awards broadcast.
3992 Release 2000f - 2000-08-10 09:31:58 -0400
3994 changes by Paul Eggert
3996 Added information in "tz-art.htm" on a Seinfeld reference to DST.
3998 Error checking and messages in the "yearistype" script have been
4002 Release 2000e - 2000-07-31 09:27:54 -0400
4004 data changes by Paul Eggert
4006 a change to the default value of the defined constant HAVE_STRERROR
4008 the addition of a Dave Barry quote on DST to the tz-arts file
4011 Release 2000d - 2000-04-20 15:43:04 -0400
4013 changes to the documentation and code of strftime for C99 conformance
4015 a bug fix for date.c
4017 These are based on (though modified from) changes by Paul Eggert.
4020 Release 2000c - 2000-03-04 10:31:43 -0500
4022 changes by Paul Eggert
4025 Release 2000b - 2000-02-21 12:16:29 -0500
4027 changes by Paul Eggert and Joseph Myers
4029 modest tweaks to the tz-art.htm and tz-link.htm files
4032 Release 2000a - 2000-01-18 09:21:26 -0500
4034 changes by Paul Eggert
4036 The two hypertext documents have also been renamed.
4039 Release code1999i-data1999j - 1999-11-15 18:43:22 -0500
4041 Paul Eggert's changes
4043 additions to the "zic" manual page and the "Arts.htm" file
4046 Release code1999h-data1999i - 1999-11-08 14:55:21 -0500
4051 Release data1999h - 1999-10-07 03:50:29 -0400
4053 changes by Paul Eggert to "europe" (most importantly, fixing
4054 Lithuania and Estonia)
4057 Release 1999g - 1999-09-28 11:06:18 -0400
4059 data changes by Paul Eggert (most importantly, the change for
4060 Lebanon that buys correctness for this coming Sunday)
4062 The "code" file contains changes to "Makefile" and "checktab.awk" to
4063 allow better checking of time zone files before they are published.
4066 Release 1999f - 1999-09-23 09:48:14 -0400
4068 changes by Arthur David Olson and Paul Eggert
4071 Release 1999e - 1999-08-17 15:20:54 -0400
4073 changes circulated by Paul Eggert, although the change to handling
4074 of DST-specifying timezone names has been commented out for now
4075 (search for "XXX" in "localtime.c" for details). These files also
4076 do not make any changes to the start of DST in Brazil.
4078 In addition to Paul's changes, there are updates to "Arts.htm" and
4082 Release 1999d - 1999-03-30 11:31:07 -0500
4084 changes by Paul Eggert
4086 The Makefile's "make public" rule has also been changed to do a test
4087 compile of each individual time zone data file (which should help
4088 avoid problems such as the one we had with Nicosia).
4091 Release 1999c - 1999-03-25 09:47:47 -0500
4093 changes by Paul Eggert, most importantly the change for Chile.
4096 Release 1999b - 1999-02-01 17:51:44 -0500
4098 changes by Paul Eggert
4100 code changes (suggested by Mani Varadarajan, mani at be.com) for
4101 correct handling of symbolic links when building using a relative directory
4103 code changes to generate correct messages for failed links
4105 updates to the URLs in Arts.htm
4108 Release 1999a - 1999-01-19 16:20:29 -0500
4110 error message internationalizations and corrections in zic.c and
4111 zdump.c (as suggested by Vladimir Michl, vladimir.michl at upol.cz,
4115 Release code1998h-data1998i - 1998-10-01 09:56:10 -0400
4117 changes for Brazil, Chile, and Germany
4119 support for use of "24:00" in the input files for the time zone compiler
4122 Release code1998g-data1998h - 1998-09-24 10:50:28 -0400
4124 changes by Paul Eggert
4126 correction to a define in the "private.h" file
4129 Release data1998g - 1998-08-11 03:28:35 -0000
4130 [tzdata1998g.tar.gz is missing!]
4132 Lithuanian change provided by mgedmin at pub.osf.it
4134 Move creation of the GMT link with Etc/GMT to "etcetera" (from
4135 "backward") to ensure that the GMT file is created even where folks
4136 don't want the "backward" links (as suggested by Paul Eggert).
4139 Release data1998f - 1998-07-20 13:50:00 -0000
4140 [tzdata1998f.tar.gz is missing!]
4142 Update the "leapseconds" file to include the newly-announced
4143 insertion at the end of 1998.
4146 Release code1998f - 1998-06-01 10:18:31 -0400
4148 addition to localtime.c by Guy Harris
4151 Release 1998e - 1998-05-28 09:56:26 -0400
4153 The Makefile is changed to produce zoneinfo-posix rather than
4154 zoneinfo/posix, and to produce zoneinfo-leaps rather than
4157 data changes by Paul Eggert
4159 changes from Guy Harris to provide asctime_r and ctime_r
4161 A usno1998 file (substantially identical to usno1997) has been added.
4164 Release 1998d - 1998-05-14 11:58:34 -0400
4166 changes to comments (in particular, elimination of references to CIA maps).
4167 "Arts.htm", "WWW.htm", "asia", and "australasia" are the only places
4168 where changes occur.
4171 Release 1998c - 1998-02-28 12:32:26 -0500
4173 changes by Paul Eggert (save the "French correction," on which I'll
4174 wait for the dust to settle)
4178 changes and additions to Arts.htm
4181 Release 1998b - 1998-01-17 14:31:51 -0500
4183 URL cleanups and additions
4186 Release 1998a - 1998-01-13 12:37:35 -0500
4188 changes by Paul Eggert
4191 Release code1997i-data1997k - 1997-12-29 09:53:41 -0500
4193 changes by Paul Eggert, with minor modifications from Arthur David
4194 Olson to make the files more browser friendly
4197 Release code1997h-data1997j - 1997-12-18 17:47:35 -0500
4199 minor changes to put "TZif" at the start of each timezone information file
4201 a rule has also been added to the Makefile so you can
4203 to just recompile the zone information files (rather than doing a
4204 full "make install" with its other effects).
4207 Release data1997i - 1997-10-07 08:45:38 -0400
4209 changes to Africa by Paul Eggert
4212 Release code1997g-data1997h - 1997-09-04 16:56:54 -0400
4214 corrections for Uruguay (and other locations)
4216 Arthur David Olson's simple-minded fix allowing mktime to both
4217 correctly handle leap seconds and correctly handle tm_sec values
4218 upon which arithmetic has been performed.
4221 Release code1997f-data1997g - 1997-07-19 13:15:02 -0400
4223 Paul Eggert's updates
4225 a small change to a function prototype;
4227 "Music" has been renamed "Arts.htm", HTMLified, and augmented to
4228 include information on Around the World in Eighty Days.
4231 Release code1997e-data1997f - 1997-05-03 18:52:34 -0400
4233 fixes to zic's error handling
4235 changes inspired by the item circulated on Slovenia
4237 The description of Web resources has been HTMLified for browsing
4240 A new piece of tz-related music has been added to the "Music" file.
4243 Release code1997d-data1997e - 1997-03-29 12:48:52 -0500
4245 Paul Eggert's latest suggestions
4248 Release code1997c-data1997d - 1997-03-07 20:37:54 -0500
4250 changes to "zic.c" to correct performance of the "-s" option
4252 a new file "usno1997"
4255 Release data1997c - 1997-03-04 09:58:18 -0500
4260 Release 1997b - 1997-02-27 18:34:19 -0500
4262 The data file incorporates the 1997 leap second.
4264 The code file incorporates Arthur David Olson's take on the
4265 zic/multiprocessor/directory-creation situation.
4268 Release 1997a - 1997-01-21 09:11:10 -0500
4270 Paul Eggert's Antarctica (and other changes)
4272 Arthur David Olson finessed the "getopt" issue by checking against
4273 both -1 and EOF (regardless of POSIX, SunOS 4.1.1's manual says -1
4274 is returned while SunOS 5.5's manual says EOF is returned).
4277 Release code1996o-data1996n - 1996-12-27 21:42:05 -0500
4279 Paul Eggert's latest changes
4282 Release code1996n - 1996-12-16 09:42:02 -0500
4284 link snapping fix from Bruce Evans (via Garrett Wollman)
4287 Release data1996m - 1996-11-24 02:37:34 -0000
4288 [tzdata1996m.tar.gz is missing!]
4290 Paul Eggert's batch of changes
4293 Release code1996m-data1996l - 1996-11-05 14:00:12 -0500
4295 No functional changes here; the files have simply been changed to
4296 make more use of ISO style dates in comments. The names of the above
4297 files now include the year in full.
4300 Release code96l - 1996-09-08 17:12:20 -0400
4302 tzcode96k was missing a couple of pieces.
4305 Release 96k - 1996-09-08 16:06:22 -0400
4307 the latest round of changes from Paul Eggert
4309 the recent Year 2000 material
4312 Release code96j - 1996-07-30 13:18:53 -0400
4314 Set sp->typecnt as suggested by Timothy Patrick Murphy.
4317 Release code96i - 1996-07-27 20:11:35 -0400
4319 Paul's suggested patch for strftime %V week numbers
4322 Release data96i - 1996-07-01 18:13:04 -0400
4324 "northamerica" and "europe" changes by Paul Eggert
4327 Release code96h - 1996-06-05 08:02:21 -0400
4329 fix for handling transitions specified in Universal Time
4331 Some "public domain" notices have also been added.
4334 Release code96g - 1996-05-16 14:00:26 -0400
4336 fix for the simultaneous-DST-and-zone-change challenge
4339 Release data96h - 1996-05-09 17:40:51 -0400
4341 changes by Paul Eggert
4344 Release code96f-data96g - 1996-05-03 03:09:59 -0000
4345 [tzcode96f.tar.gz + tzdata96g.tar.gz are both missing!]
4347 The changes get us some of the way to fixing the problems noted in Paul
4348 Eggert's letter yesterday (in addition to a few others). The approach
4349 has been to make zic a bit smarter about figuring out what time zone
4350 abbreviations apply just after the time specified in the "UNTIL" part
4351 of a zone line. Putting the smarts in zic means avoiding having
4352 transition times show up in both "Zone" lines and "Rule" lines, which
4353 in turn avoids multiple transition time entries in time zone files.
4354 (This also makes the zic input files such as "europe" a bit shorter and
4355 should ease maintenance.)
4358 Release data96f - 1996-04-19 19:20:03 -0000
4359 [tzdata96f.tar.gz is missing!]
4361 The only changes are to the "northamerica" file; the time zone
4362 abbreviation for Denver is corrected to MST (and MDT), and the
4363 comments for Mexico have been updated.
4366 Release data96e - 1996-03-19 17:37:26 -0500
4368 Proposals by Paul Eggert, in particular the Portugal change that
4369 comes into play at the end of this month.
4372 Release data96d - 1996-03-18 20:49:39 -0500
4377 Release code96e - 1996-02-29 15:43:27 -0000
4378 [tzcode96e.tar.gz is missing!]
4380 internationalization changes and the fix to the documentation for strftime
4383 Release code96d-data96c - 1996-02-12 11:05:27 -0500
4385 The "code" file simply updates Bob Kridle's electronic address.
4387 The "data" file updates rules for Mexico.
4390 Release data96b - 1996-01-27 15:44:42 -0500
4395 Release code96c - 1996-01-16 16:58:15 -0500
4397 leap-year streamlining and binary-search changes
4402 Release code96b - 1996-01-10 20:42:39 -0500
4404 fixes and enhancements from Paul Eggert, including code that
4405 emulates the behavior of recent versions of the SunOS "date"
4409 Release 96a - 1996-01-06 09:08:24 -0500
4413 fixes to strftime.c for correct ISO 8601 week number generation,
4414 plus support for two new formats ('G' and 'g') to give ISO 8601 year
4415 numbers (which are not necessarily the same as calendar year numbers)
4418 Release code95i-data95m - 1995-12-21 12:46:47 -0500
4420 The latest revisions from Paul Eggert are included, the usno1995
4421 file has been updated, and a new file ("WWW") covering useful URLs
4425 Release code95h-data95l - 1995-12-19 18:10:12 -0500
4427 A simplification of a macro definition, a change to data for Sudan,
4428 and (for last minute shoppers) notes in the "Music" file on the CD
4432 Release code95g-data95k - 1995-10-30 10:32:47 -0500
4434 (slightly reformatted) 8-bit-clean proposed patch
4436 minor patch: US/Eastern -> America/New_York
4438 snapshot of the USNO's latest data ("usno1995")
4440 some other minor cleanups
4443 Release code95f-data95j - 1995-10-28 21:01:34 -0000
4444 [tzcode95f.tar.gz + tzdata95j.tar.gz are both missing!]
4448 support for 64-bit time_t's
4450 optimization in localtime.c
4453 Release code95e - 1995-10-13 13:23:57 -0400
4455 the mktime change to scan from future to past when trying to find time zone
4459 Release data95i - 1995-09-26 10:43:26 -0400
4461 For Canada/Central, guess that the Sun customer's "one week too
4462 early" was just a approximation, and the true error is one month
4463 too early. This is consistent with the rest of Canada.
4466 Release data95h - 1995-09-21 11:26:48 -0400
4468 latest changes from Paul Eggert
4471 Release code95d - 1995-09-14 11:14:45 -0400
4473 the addition of a "Music" file, which documents four recorded
4474 versions of the tune "Save That Time".
4477 Release data95g - 1995-09-01 17:21:36 -0400
4479 "yearistype" correction
4482 Release data95f - 1995-08-28 20:46:56 -0400
4484 Paul Eggert's change to the australasia file
4487 Release data95e - 1995-07-08 18:02:34 -0400
4489 The only change is a leap second at the end of this year.
4490 Thanks to Bradley White for forwarding news on the leap second.
4493 Release data95d - 1995-07-03 13:26:22 -0400
4495 Paul Eggert's changes
4498 Release data95c - 1995-07-02 19:19:28 -0400
4500 changes to "asia", "backward", "europe", and "southamerica"
4501 (read: northamericacentrics need not apply)
4504 Release code95c - 1995-03-13 14:00:46 -0500
4506 one-line fix for sign extension problems in detzcode
4509 Release 95b - 1995-03-04 11:22:38 -0500
4511 Minor changes in both:
4513 The "code" file contains a workaround for the lack of "unistd.h" in
4514 Microsoft C++ version 7.
4516 The "data" file contains a fixed "Link" for America/Shiprock.
4519 Release 94h - 1994-12-10 12:51:14 -0500
4523 * incorporate the changes to "zdump" and "date" to make changes to
4524 the "TZ" environment variable permanent;
4526 * incorporate the table changes by Paul Eggert;
4528 * include (and document) support for universal time specifications in
4529 data files - but do not (yet) include use of this feature in the
4532 Think of this as "TZ Classic" - the software has been set up not to break if
4533 universal time shows up in its input, and data entries have been
4534 left as is so as not to break existing implementations.
4537 Release data94f - 1994-08-20 12:56:09 -0400
4539 (with thanks!) the latest data updates from Paul Eggert
4542 Release data94e - 1994-06-04 13:13:53 -0400
4547 Release code94g - 1994-05-05 12:14:07 -0400
4549 fix missing "optind.c" and a reference to it in the Makefile
4552 Release code94f - 1994-05-05 13:00:33 -0000
4553 [tzcode94f.tar.gz is missing!]
4555 changes to avoid overflow in difftime, as well as changes to cope
4556 with the 52/53 challenge in strftime
4559 Release code94e - 1994-03-30 23:32:59 -0500
4561 change for the benefit of PCTS
4564 Release 94d - 1994-02-24 15:42:25 -0500
4566 Avoid clashes with POSIX semantics for zones such as GMT+4.
4568 Some other very minor housekeeping is also present.
4571 Release code94c - 1994-02-10 08:52:40 -0500
4573 Fix bug where mkdirs was broken unless you compile with
4574 -fwritable-strings (which is generally losing to do).
4577 Release 94b - 1994-02-07 10:04:33 -0500
4579 work by Paul Eggert who notes:
4581 I found another book of time zone histories by E W Whitman; it's not
4582 as extensive as Shanks but has a few goodies of its own. I used it
4583 to update the tables. I also fixed some more as a result of
4584 correspondence with Adam David and Peter Ilieve, and move some stray
4585 links from 'europe' to 'backward'. I corrected some scanning errors
4588 As far as the code goes, I fixed zic to allow years in the range
4589 INT_MIN to INT_MAX; this fixed a few boundary conditions around 1900.
4590 And I cleaned up the zic documentation a little bit.
4593 Release data94a - 1994-02-03 08:58:54 -0500
4595 It simply incorporates the recently announced leap second into the
4599 Release 93g - 1993-11-22 17:28:27 -0500
4601 Paul Eggert has provided a good deal of historic information (based
4602 on Shanks), and there are some code changes to deal with the buglets
4603 that crawled out in dealing with the new information.
4606 Release 93f - 1993-10-15 12:27:46 -0400
4608 Paul Eggert's changes
4611 Release 93e - 1993-09-05 21:21:44 -0400
4613 This has updated data for Israel, England, and Kwajalein. There's
4614 also an update to "zdump" to cope with Kwajalein's 24-hour jump.
4615 Thanks to Paul Eggert and Peter Ilieve for the changes.
4618 Release 93d - 1993-06-17 23:34:17 -0400
4620 new fix and new data on Israel
4623 Release 93c - 1993-06-06 19:31:55 -0400
4628 Release 93b - 1993-02-02 14:53:58 -0500
4630 updated "leapseconds" file
4633 Release 93 - 1993-01-08 07:01:06 -0500
4635 At kre's suggestion, the package has been split in two - a code piece
4636 (which also includes documentation) that's only of use to folks who
4637 want to recompile things and a data piece useful to anyone who can
4640 The new version has a few changes to the data files, a few
4641 portability changes, and an off-by-one fix (with thanks to
4642 Tom Karzes at deshaw.com for providing a description and a
4646 Release 92c - 1992-11-21 17:35:36 -0000
4647 [tz92c.tar.Z is missing!]
4649 The fallout from the latest round of DST transitions.
4651 There are changes for Portugal, Saskatchewan, and "Pacific-New";
4652 there's also a change to "zic.c" that makes it portable to more systems.
4655 Release 92 - 1992-04-25 18:17:03 -0000
4656 [tz92.tar.Z is missing!]
4658 By popular demand (well, at any rate, following a request by kre at munnari)
4661 The 1989 update of the time zone package featured:
4663 * POSIXization (including interpretation of POSIX-style TZ environment
4664 variables, provided by Guy Harris),
4665 * ANSIfication (including versions of "mktime" and "difftime"),
4666 * SVIDulation (an "altzone" variable)
4667 * MACHination (the "gtime" function)
4668 * corrections to some time zone data (including corrections to the rules
4669 for Great Britain and New Zealand)
4670 * reference data from the United States Naval Observatory for folks who
4671 want to do additional time zones
4672 * and the 1989 data for Saudi Arabia.
4674 (Since this code will be treated as "part of the implementation" in some
4675 places and as "part of the application" in others, there's no good way to
4676 name functions, such as timegm, that are not part of the proposed ANSI C
4677 standard; such functions have kept their old, underscore-free names in this
4680 And the "dysize" function has disappeared; it was present to allow
4681 compilation of the "date" command on old BSD systems, and a version of "date"
4682 is now provided in the package. The "date" command is not created when you
4683 "make all" since it may lack options provided by the version distributed with
4684 your operating system, or may not interact with the system in the same way
4685 the native version does.
4687 Since POSIX frowns on correct leap second handling, the default behavior of
4688 the "zic" command (in the absence of a "-L" option) has been changed to omit
4689 leap second information from its output files.
4695 This file contains copies of the part of each release announcement
4696 that talks about the changes in that release. The text has been
4697 adapted and reformatted for the purposes of this file.
4699 Traditionally a release R consists of a pair of tarball files,
4700 tzcodeR.tar.gz and tzdataR.tar.gz. However, some releases (e.g.,
4701 code2010a, data2012c) consist of just one or the other tarball, and a
4702 few (e.g., code2012c-data2012d) have tarballs with mixed version
4703 numbers. Recent releases also come in an experimental format
4704 consisting of a single tarball tzdb-R.tar.lz with extra data.
4706 Release timestamps are taken from the release's commit (for newer,
4707 Git-based releases), from the newest file in the tarball (for older
4708 releases, where this info is available) or from the email announcing
4709 the release (if all else fails; these are marked with a time zone
4710 abbreviation of -0000 and an "is missing!" comment).
4712 Earlier versions of the code and data were not announced on the tz
4713 list and are not summarized here.
4715 This file is in the public domain.