September 2021 - tz - lists.iana.org

(no subject)
by Cool Gab19 Nov. 7, 2024

Nov. 7, 2024

can you add Philippine Daylight Time on your Database I think it was missing from the list of the time zones please reply immediately if solved thanks...

4 8

Re: [tz] Morocco : Ramdan Time Change 2021
by Paul Eggert March 15, 2023

March 15, 2023

On 3/19/21 3:15 AM, Semlali Naoufal wrote: > At the moment, we have no official government announcement to this effect. But, logically, the change to the GMT schedule should be made on the night of April 10-11, 2021 (last weekend before Ramadan). Yes, that's been the tzdb prediction too, ever since tzdb version 2018h (2018-12-23). For the record, here are tzdb's current predictions Morocco transitions during the next five years. Sun Apr 11 01:59:59 2021 UT = Sun Apr 11 02:59:59 2021 +01 Sun Apr 11 02:00:00 2021 UT = Sun Apr 11 02:00:00 2021 +00 Sun May 16 01:59:59 2021 UT = Sun May 16 01:59:59 2021 +00 Sun May 16 02:00:00 2021 UT = Sun May 16 03:00:00 2021 +01 Sun Mar 27 01:59:59 2022 UT = Sun Mar 27 02:59:59 2022 +01 Sun Mar 27 02:00:00 2022 UT = Sun Mar 27 02:00:00 2022 +00 Sun May 8 01:59:59 2022 UT = Sun May 8 01:59:59 2022 +00 Sun May 8 02:00:00 2022 UT = Sun May 8 03:00:00 2022 +01 Sun Mar 19 01:59:59 2023 UT = Sun Mar 19 02:59:59 2023 +01 Sun Mar 19 02:00:00 2023 UT = Sun Mar 19 02:00:00 2023 +00 Sun Apr 30 01:59:59 2023 UT = Sun Apr 30 01:59:59 2023 +00 Sun Apr 30 02:00:00 2023 UT = Sun Apr 30 03:00:00 2023 +01 Sun Mar 10 01:59:59 2024 UT = Sun Mar 10 02:59:59 2024 +01 Sun Mar 10 02:00:00 2024 UT = Sun Mar 10 02:00:00 2024 +00 Sun Apr 14 01:59:59 2024 UT = Sun Apr 14 01:59:59 2024 +00 Sun Apr 14 02:00:00 2024 UT = Sun Apr 14 03:00:00 2024 +01 Sun Feb 23 01:59:59 2025 UT = Sun Feb 23 02:59:59 2025 +01 Sun Feb 23 02:00:00 2025 UT = Sun Feb 23 02:00:00 2025 +00 Sun Apr 6 01:59:59 2025 UT = Sun Apr 6 01:59:59 2025 +00 Sun Apr 6 02:00:00 2025 UT = Sun Apr 6 03:00:00 2025 +01 Sun Feb 15 01:59:59 2026 UT = Sun Feb 15 02:59:59 2026 +01 Sun Feb 15 02:00:00 2026 UT = Sun Feb 15 02:00:00 2026 +00 Sun Mar 22 01:59:59 2026 UT = Sun Mar 22 01:59:59 2026 +00 Sun Mar 22 02:00:00 2026 UT = Sun Mar 22 03:00:00 2026 +01 Sun Feb 7 01:59:59 2027 UT = Sun Feb 7 02:59:59 2027 +01 Sun Feb 7 02:00:00 2027 UT = Sun Feb 7 02:00:00 2027 +00 Sun Mar 14 01:59:59 2027 UT = Sun Mar 14 01:59:59 2027 +00 Sun Mar 14 02:00:00 2027 UT = Sun Mar 14 03:00:00 2027 +01 Sun Jan 23 01:59:59 2028 UT = Sun Jan 23 02:59:59 2028 +01 Sun Jan 23 02:00:00 2028 UT = Sun Jan 23 02:00:00 2028 +00 Sun Mar 5 01:59:59 2028 UT = Sun Mar 5 01:59:59 2028 +00 Sun Mar 5 02:00:00 2028 UT = Sun Mar 5 03:00:00 2028 +01 Sun Jan 14 01:59:59 2029 UT = Sun Jan 14 02:59:59 2029 +01 Sun Jan 14 02:00:00 2029 UT = Sun Jan 14 02:00:00 2029 +00 Sun Feb 18 01:59:59 2029 UT = Sun Feb 18 01:59:59 2029 +00 Sun Feb 18 02:00:00 2029 UT = Sun Feb 18 03:00:00 2029 +01 Sun Dec 30 01:59:59 2029 UT = Sun Dec 30 02:59:59 2029 +01 Sun Dec 30 02:00:00 2029 UT = Sun Dec 30 02:00:00 2029 +00 Sun Feb 10 01:59:59 2030 UT = Sun Feb 10 01:59:59 2030 +00 Sun Feb 10 02:00:00 2030 UT = Sun Feb 10 03:00:00 2030 +01 Sun Dec 22 01:59:59 2030 UT = Sun Dec 22 02:59:59 2030 +01 Sun Dec 22 02:00:00 2030 UT = Sun Dec 22 02:00:00 2030 +00

3 9

United States Senate reintroduced Sunshine Protection Act, enabling Permanent DST
by Phake Nick Nov. 14, 2022

Nov. 14, 2022

I don't quite understand the legal text of the bill itself [2], but according to my reading, it seems like the bill will end DST across the entire US by shifting the standard time forward an hour, except in states/territories/area that currently doesn't enact DST, which they can choose to follow the new standard time or old standard time? 1: https://www.rubio.senate.gov/public/index.cfm/2021/3/rubio-colleagues-reint… 2: https://www.rubio.senate.gov/public/_cache/files/d34c77c0-acea-4074-bc57-14…

18 26

Re: [tz] iana build failures on Windows
by Paul Eggert Nov. 2, 2022

Nov. 2, 2022

On 4/19/21 7:09 AM, Manuela Friedrich wrote: > I had to include signal.h in zic.c to prevent the following error: > > zic.c(610): error C2061: syntax error: identifier 'got_signal' This is a portability bug recently introduced to zic.c. I installed the first attached patch to fix it. > The I needed to resolved error > > zic.obj : error LNK2019: unresolved external symbol tz_time referenced in function random_dirent This appears to be another recent portability bug. It's related to a portability problem you reported on MS-Windows in response to which in 2018d I committed a patch that introduced RESERVE_STD_EXT_IDS: https://github.com/eggert/tz/commit/24b45243c5210b4196987fdd06e6c288c358a268 When I recently added the randomish filename code to the development version, I neglected to deal with RESERVE_STD_EXT_IDS. The second attached patch should fix this issue. Please give the two patches a try, as I don't use MS-Windows and can't easily test these patches on that platform. > a test run of zdump -v produced way more output than in the last release, the Linux output seems to have become longer too, but maybe this is still under development. That change is intentional, and was caused by this: https://github.com/eggert/tz/commit/ac07b446a3afaa4cb1ae11a91785a201c91f6351 along with some neighboring commits. Thanks for reporting the problems, and I hope the current development version of tzdb addresses the issues you mentioned.

5 23

Re: [tz] Change Request: Europe/Kiev to Europe/Kyiv
by John Hawkinson March 18, 2022

March 18, 2022

I do not think we have handled this well; we have not given Victor Perov a good answer. Indeed, to some extent we've made it a "runaround." We can do better. We should take the time to write up a good lengthy explanation of the issues ("boilerplate"), because this a really important issue of concern to many people in the world and the project has indeed thought about it pretty carefully. Dismissing the inquiries because they are repetitive makes it seem like we haven't, and that unnecessarily upsets peopl. Victor Perev: I don't have time for a full write-up right now, but please consult the archives of the tz list (http://mm.icann.org/pipermail/tz/ or perhaps https://www.google.com/search?q=site%3Amm.icann.org%2Fpipermail%2Ftz%2F+kyiv which returns 203 results). The tz project is very conservative in its judgment for when the predominant English spelling of a city has changed, and so far the project has judged that Kiev is still preferred. We discussed it when major English newspapers and style guides changed from Kiev to Kyiv last year (prompted by the US presidential impeachment, which lead to a lot of discussion about Kyiv in America), and we will probably continue to discuss it as time goes on. But we've thought about it and discussed it a lot. The answers you got don't explain that, and that means we have not done a good a job as we should have. Sorry about that. In particular, I think Brian Inglis's answer was actually incorrect in a way that really matters ("Kiev is the correct English spelling"). There are multiple correct English spellings. It used to be that Kiev was the only one, but Kyiv is gaining popularity more and more. Paul Eggert <eggert(a)cs.ucla.edu> wrote on Sat, 15 Aug 2020 at 18:19:08 EDT in <cefc7f01-a3e9-f2a4-9ab9-5288147f994a(a)cs.ucla.edu>: > Thanks for bringing that to the mailing list (if I could shut off GitHub > pull requests I would). Although you cannot do so, we can handle them a little bit better. Please see https://docs.github.com/en/github/building-a-strong-community/creating-a-pu… You can create a template that explains to a would-be pull request submitter than pull requests will be closed and the project uses the mailing list for development discussions. ("I understand that the tz project does not use pull requests on github, and that if I enter a pull request here, it will be closed and I will be directed to send email to tz(a)iana.org.") For the particular case of regular, recurring issues, it may be worth while to keep one of #15, #26, and #27 open and mark the others as a duplicate of it, so that it is easier for newcomers to understand that this issue has been carefully considered and is not a simple oversight. https://github.com/eggert/tz/pulls?q=kiev Also, not to pick on Brian (again), but if the project policy is not to use github pull requests, it's not great to respond to pull requests on their substance, because it bifurcates the discussion and makes it seem like we actually do use pull requests ("except when we don't"). So what seems like a helpful thing may not be. -- jhawk(a)alum.mit.edu John Hawkinson

10 13

TZDB use cases
by Stephen Colebourne Oct. 7, 2021

Oct. 7, 2021

In this thread I want to try and capture the *requirements* for the project from the perspective of a downstream user. Given this, we may then have a chance to analyse whether the project needs a change of rules. NOTE: The discussion below is not a proposal, nor does it seek to explore which locations get pre-1970 data. Lets keep that for another thread. -------- 1) "What is the time now?" To answer this question you need a dataset that records the current timezone rules for each region in the world. Over time that data will naturally build up to form a historic record. To aid the project, a 1970 rule has been adopted for data management. In some parts of the world, clocks have agreed since 1970 across large parts of a continent. In other parts of the world, different parts of the same country have had different rules since 1970. Viewing the data through a post-1970 lens splits the planet into regions where clocks have agreed since 1970. Some of these regions are quite abstract, for example the region including Iceland, Ivory Coast, and St Helena. An abstract region would need to be split if one of the parts of the region changed its timezone rules. If a user had previously selected to follow one of these abstract regions, they might have to change their timezone settings. For example, if a user in Iceland selected their abstract region by the recommended ID based on the largest city they would get `Africa/Abidjan`, but if the Ivory Coast changed their rules, users in Iceland would have to change their selected timezone. The minimum set of IDs is one ID for each abstract region. The current ID scheme selects the largest city in the abstract region. My interpretation: * An abstract region should theoretically have an ID separate to the IDs of the cities/countries in the region * Trying the ID of the abstract region to the largest city in the region is prone to failure if that city changes timezone rules but the rest of the abstract region stays the same. * An abstract region ID would naturally have no pre-1970 data, as it doesn't define data in a single city/location. * The alternative is to encourage users to use their local city, which means that IDs like Europe/Amsterdam and Europe/Oslo cannot be deprecated -------- 2) "What was the time at some instant in the past?" The project can answer this question pretty reliably for dates from 1970 onwards because of the data set in #1. The project can never realistically answer the question reliably or accurately before 1970 for *all* locations. For example, timezone rules were entirely local in the US for about 20 years, meaning that hundreds of entries would be needed to correctly capture the data. In addition, much of the historic data globally is unknown and not viable to research, even if someone wanted to do so. It is possible to research and record historic timezone rules for *some* locations. Europe/London being one example. The project generally operates on the basis that if an ID exists, historical data can be recorded against it, although which file that data lives in has varied over time. IDs are generally not created solely to document historic data. There is no minimum set of IDs for this use case - the set of possible IDs is unbounded. My interpretation: * The majority of pre-1970 data isn't much use * Some pre-1970 data is high quality, and almost certainly relied upon (eg Europe/London) * Without a massive increase in scope the best that can be done pre-1970 is to record data against IDs created for some other reason. -------- 3) "An event will happen at this time in the future" If an end-user wants to store an event in the future, eg. a one hour meeting next month, the correct approach is to store the date, time and zone ID, not the offset (which is not yet known for certain).Even if the local timezone authority changes the tz rules between now and the event, the time of the event is still correct. https://stackoverflow.com/questions/19166995/java-calendar-date-and-time-ma… For this approach to work, the ID that is stored must be aligned with the timezone authority. Business contracts are frequently written to describe future events. For example, payment must be made by 2pm Paris time on a given date. The minimum set of IDs for this use case is one ID per timezone authority. This is typically the country but not necessarily, examples being decisions devolved to states/nations etc. My interpretation: * Using TZDB IDs for future events/contracts is very widespread * In most parts of the world, this requires one ID per country, in some parts of the world additional IDs would ideally be needed such as per state in the US * One ID for each ISO country (as was the guideline in the past) is a reasonable minimum expectation of end users * While one might argue IDs for future events are not TZDBs problem, I believe the reality is that they are because usage in this way is already very widespread -------- 4) "An event will happen at this time in the future relative to a shared/common definition" Some future events are declared relative to a definition that is supra-national or federal. For example, US Mountain, US Pacific, EU Central etc. A TV show might be defined to air at 8pm Mountain Time in one months time. It will air at that time regardless of whether any of the states that are currently on Mountain Time change to Pacific Time. For example, even if Denver (and Colorado) moved to Pacific Time or stopped following DST, Mountain Time would still exist and the TV show would still air at 8pm Mountain. The minimum set of IDs for this use case is one ID per shared/common definition. These IDs are not full aliases for a country or city ID, although they may currently share data. To support this use case, these IDs cannot be deprecated. My interpretation: * Some shared zone IDs are distinct and separate enough to warrant a full ID * US Mountain time is not the same as Denver time when considering the future, the IDs could diverge * In TZDB terms, the Link from US/Mountain to America/Denver is fine to define the data, but US/Mountain should not be considered deprecated as it has a real and distinct meaning separate from America/Denver * It would be useful to agree what the criteria for including these shared/federal rules is. -------- 5) "Data should be backwards compatible" The project has various associated downstream projects. Many of these have an expectation of backwards compatibility. This compatibility extends to the binary format, the source format, and the data contained within. This use case wants to see the project just continue with the data it has, enhancing it over time. The project has a pretty good record in terms of not removing IDs. For example, IDs exist for "Portugal" and "Poland", but not "Italy" or "Spain" simply because they were defined once upon a time. My understanding is that IDs in the `backward` file represent deprecated IDs that should not be used going forward. Yet, downstream projects focussed on backwards compatibility will generally use the `backward` file in full. The minimum set of IDs for this use case is the set of IDs that existed in the previous release. My interpretation: * Many users care about compatibility * The current IDs are not going away * Inconsistency has existed in TZDB for many years, see "Portugal" vs "Spain" - no one wants to fix that * It is hard at present to identify IDs that are deprecated because of proper aliasing, such as spelling changes, vs those where the ID is a real location but its TZDB status has been reduced. * Change may be possible with a long notice period --------- Please note that the above is not a proposal, but an exploration of the design space. If you have any use cases I've missed feel free to write them up. thanks Stephen

10 23

timezone Verschlimmbesserung
by Tony Finch Oct. 6, 2021

Oct. 6, 2021

Paul Eggert's rationale is informative https://mm.icann.org/pipermail/tz/2021-September/030764.html But I think there are a few more things to say. The aim of merging timezones was to avoid political issues and to reduce the maintenance burden. It seems to me that it has failed to achieve those goals. There have been several very long discussions on the topic, and the recent arguments are making exactly the same points as were made in 2013. So I think the changes have increased the amount of political discussion and controversy on the tz list, not reduced it. https://mm.icann.org/pipermail/tz/2013-May/thread.html https://mm.icann.org/pipermail/tz/2013-August/thread.html https://mm.icann.org/pipermail/tz/2013-September/thread.html Paul says in his rationale that it was a lot of extra work, and in other messages he said that he has found it hard to keep up with the discussions. So merging timezones has increased the maintenance burden, not reduced it. I have identified two policy changes that caused this argument. In 2013, Paul Eggert started a new policy of merging timezones that are the same since 1970. As far as I can tell, no-one wanted this other than Paul. This merging policy was applied first to places with small populations, and (because of alphabetical order) to Africa, which is not well-represented by the people on the TZ list. Some of the merges also ignored the guideline that each country should have at least one timezone to call its own. The other policy change was to drop the guideline that each country should have at least one timezone. This change occurred in 2019, buried at the end of a very long discussion about Vietnam, and presented as a fait accompli. https://mm.icann.org/pipermail/tz/2019-February/027602.html This was after a great deal of discussion about the need to retain country information in the tz database, back in 2013 when these changes started. As I understand it, the equity / fairness issue is that the timezone merges were implemented in an unfair manner, affecting Africa (since 2014, against the guidelines as written at the time) but not Europe. So although Paul says the merges worked without significant incident, they did in fact cause a political complaint - exactly what the merges were supposed to avoid. The current argument was triggered by the question of whether this fairness issue should be addressed by undoing the data loss in the compiled tz files that caused the complaint, or by imposing the data loss more strictly. I think the way to fix this is to revert both policy changes, and revert all the timezone merges. Tony. -- f.anthony.n.finch <dot(a)dotat.at> https://dotat.at/ Lundy, Fastnet, Irish Sea: Northwest 4 to 6, backing southwest 5 to 7, perhaps gale 8 later. Slight or moderate until later in Irish Sea and Lundy, otherwise moderate or rough. Rain or showers. Good, occasionally poor.

7 10

Italy April 1944 discrepancy between comment and data
by Alois Treindl Oct. 5, 2021

Oct. 5, 2021

For Italy in 1944 zone Europe/Rome there is a discrepancy between the comment and the data. comment: # From Paul Eggert (2016-10-27): # Go with INRiM for DST rules, except as corrected by Inglis for 1944 # for the Kingdom of Italy. This is consistent with Renzo Baldini. # Model Rome's occupation by using C-Eur rules from 1943-09-10 # to 1944-06-04; although Rome was an open city during this period, it # was effectively controlled by Germany. Data for Italy is Rule Italy 1944 only - Apr 2 2:00s 1:00 S Data for C-Eur is: Rule C-Eur 1944 1945 - Apr Mon>=1 2:00s 1:00 S where Mon>=1 in 1944 is April 3. So Rome is NOT following C-Eur. I think the rule for Itay is right, only the comment is misleading.

4 9

32-bit section missing transitions in 2021b
by Daniel Fischer Oct. 1, 2021

Oct. 1, 2021

Hi, It looks like 32-bit data generated by 2021b is missing the effects of transitions below INT32_MIN. Before commit 93132d18, zones had a transition at INT32_MIN to the type in use at that time. For example, the Pacific/Port_Moresby zone used to have these two transitions: -2147483648 -> 1 (+10) 2147483647 -> 1 (+10) Starting with commit 93132d18, including in 2021b, only one transition is present: 2147483647 -> 1 (+10) Since clients are supposed to assume type 0 before the earliest transition, this almost always leads to wrong times for some period of time (or all times for extreme cases like Port Moresby). Danny -- Daniel Fischer Rastatt, Germany Oracle Global Services Germany GmbH

3 3

[tz-announce] 2021b release of tz code and data available
by Paul Eggert via tz-announce Oct. 1, 2021

Oct. 1, 2021

The 2021b release of the tz code and data is available. Partly because it's been so long since 2021a, this release has many changes, noted below. In one area, noted "Merge more location-based Zones" below, the mailing list has had significant trouble coming to a long-term consensus. Because we should publish something before the Samoa change takes effect, this release contains just one step towards making tzdb fairer and more equitable in future releases. This release reflects the following changes, which were either circulated on the tz mailing list or are relatively minor technical or administrative changes: Briefly: Jordan now starts DST on February's last Thursday. Samoa no longer observes DST. Merge more location-based Zones whose timestamps agree since 1970. Move some backward-compatibility links to 'backward'. Rename Pacific/Enderbury to Pacific/Kanton. Correct many pre-1993 transitions in Malawi, Portugal, etc. zic now creates each output file or link atomically. zic -L no longer omits the POSIX TZ string in its output. zic fixes for truncation and leap second table expiration. zic now follows POSIX for TZ strings using all-year DST. Fix some localtime crashes and bugs in obscure cases. zdump -v now outputs more-useful boundary cases. tzfile.5 better matches a draft successor to RFC 8536. A new file SECURITY. This release is prompted by recent announcements by Jordan and Samoa. It incorporates many other changes that had accumulated since 2021a. However, it omits most proposed changes that merged all Zones agreeing since 1970, as concerns were raised about doing too many of these changes at once. It does keeps some of these changes in the interest of making tzdb more equitable one step at a time; see "Merge more location-based Zones" below. Changes to future timestamps Jordan now starts DST on February's last Thursday. (Thanks to Steffen Thorsen.) Samoa no longer observes DST. (Thanks to Geoffrey D. Bennett.) Changes to zone name Rename Pacific/Enderbury to Pacific/Kanton. When we added Enderbury in 1993, we did not know that it is uninhabited and that Kanton (population two dozen) is the only inhabited location in that timezone. The old name is now a backward-compatility link. Changes to past timestamps Correct many pre-1993 transitions, fixing entries originally derived from Shanks, Whitman, and Mundell. The fixes include: - Barbados: standard time was introduced in 1911, not 1932; and DST was observed in 1942-1944 - Cook Islands: In 1899 they switched from east to west of GMT, celebrating Christmas for two days. They (and Niue) switched to standard time in 1952, not 1901. - Guyana: corrected LMT for Georgetown; the introduction of standard time in 1911, not 1915; and corrections to 1975 and 1992 transitions - Kanton: uninhabited before 1937-08-31 - Niue: only observed -11:20 from 1952 through 1964, then went to -11 instead of -11:30 - Portugal: DST was observed in 1950 - Tonga: corrected LMT; the introduction of standard time in 1945, not 1901; and corrections to the transition from +12:20 to +13 in 1961, not 1941 Additional fixes to entries in the 'backzone' file include: - Enderbury: inhabited only 1860/1885 and 1938-03-06/1942-02-09 - The Gambia: 1933 and 1942 transitions - Malawi: several 1911 through 1925 transitions - Sierra Leone: several 1913 through 1941 transitions, and DST was NOT observed in 1957 through 1962 (Thanks to P Chan, Michael Deckers, Alexander Krivenyshev and Alois Treindl.) Merge more location-based Zones whose timestamps agree since 1970, as pre-1970 timestamps are out of scope. This is part of a process that has been ongoing since 2013. This does not affect post-1970 timestamps, and timezone historians who build with 'make PACKRATDATA=backzone' should see no changes to pre-1970 timestamps. When merging, keep the most-populous location's data, and move data for other locations to 'backzone' with a backward link in 'backward'. For example, move America/Creston data to 'backzone' with a link in 'backward' from America/Phoenix because the two timezones' timestamps agree since 1970; this change affects some pre-1968 timestamps in America/Creston because Creston and Phoenix disagreed before 1968. The affected Zones are Africa/Accra, America/Atikokan, America/Blanc-Sablon, America/Creston, America/Curacao, America/Nassau, America/Port_of_Spain, Antarctica/DumontDUrville, and Antarctica/Syowa. Changes to maintenance procedure The new file SECURITY covers how to report security-related bugs. Several backward-compatibility links have been moved to the 'backward' file. These links, which range from Africa/Addis_Ababa to Pacific/Saipan, are only for compatibility with now-obsolete guidelines suggesting an entry for every ISO 3166 code. The intercontinental convenience links Asia/Istanbul and Europe/Nicosia have also been moved to 'backward'. Changes to code zic now creates each output file or link atomically, possibly by creating a temporary file and then renaming it. This avoids races where a TZ setting would temporarily stop working while zic was installing a replacement file or link. zic -L no longer omits the POSIX TZ string in its output. Starting with 2020a, zic -L truncated its output according to the "Expires" directive or "#expires" comment in the leapseconds file. The resulting TZif files omitted daylight saving transitions after the leap second table expired, which led to far less-accurate predictions of times after the expiry. Although future timestamps cannot be converted accurately in the presence of leap seconds, it is more accurate to convert near-future timestamps with a few seconds error than with an hour error, so zic -L no longer truncates output in this way. Instead, when zic -L is given the "Expires" directive, it now outputs the expiration by appending a no-change entry to the leap second table. Although this should work well with most TZif readers, it does not conform to Internet RFC 8536 and some pickier clients (including tzdb 2017c through 2021a) reject it, so "Expires" directives are currently disabled by default. To enable them, set the EXPIRES_LINE Makefile variable. If a TZif file uses this new feature it is marked with a new TZif version number 4, a format intended to be documented in a successor to RFC 8536. zic -L LEAPFILE -r @LO no longer generates an invalid TZif file that omits leap second information for the range LO..B when LO falls between two leap seconds A and B. Instead, it generates a TZif version 4 file that represents the previously-missing information. The TZif reader now allows the leap second table to begin with a correction other than -1 or +1, and to contain adjacent transitions with equal corrections. This supports TZif version 4. The TZif reader now lets leap seconds occur less than 28 days apart. This supports possible future TZif extensions. Fix bug that caused 'localtime' etc. to crash when TZ was set to a all-year DST string like "EST5EDT4,0/0,J365/25" that does not conform to POSIX but does conform to Internet RFC 8536. Fix another bug that caused 'localtime' etc. to crash when TZ was set to a POSIX-conforming but unusual TZ string like "EST5EDT4,0/0,J365/0", where almost all the year is DST. Fix yet another bug that caused 'localtime' etc. to mishandle slim TZif files containing leap seconds after the last explicit transition in the table, or when handling far-future timestamps in slim TZif files lacking leap seconds. Fix localtime misbehavior involving positive leap seconds. This change affects only behavior for "right" system time, which contains leap seconds, and only if the UT offset is not a multiple of 60 seconds when a positive leap second occurs. (No such timezone exists in tzdb, luckily.) Without the fix, the timestamp was ambiguous during a positive leap second. With the fix, any seconds occurring after a positive leap second and within the same localtime minute are counted through 60, not through 59; their UT offset (tm_gmtoff) is the same as before. Here is how the fix affects timestamps in a timezone with UT offset +01:23:45 (5025 seconds) and with a positive leap second at 1972-06-30 23:59:60 UTC (78796800): time_t without the fix with the fix 78796800 1972-07-01 01:23:45 1972-07-01 01:23:45 (leap second) 78796801 1972-07-01 01:23:45 1972-07-01 01:23:46 ... 78796815 1972-07-01 01:23:59 1972-07-01 01:23:60 78796816 1972-07-01 01:24:00 1972-07-01 01:24:00 Fix an unlikely bug that caused 'localtime' etc. to misbehave if civil time changes a few seconds before time_t wraps around, when leap seconds are enabled. Fix bug in zic -r; in some cases, the dummy time type after the last time transition disagreed with the TZ string, contrary to Internet RFC 8563 section 3.3. Fix a bug with 'zic -r @X' when X is a negative leap second that has a nonnegative correction. Without the fix, the output file was truncated so that X appeared to be a positive leap second. Fix a similar, even-less-likely bug when truncating at a positive leap second that has a nonpositive correction. zic -r now reports an error if given rolling leap seconds, as this usage has never generally worked and is evidently unused. zic now generates a POSIX-conforming TZ string for TZif files where all-year DST is predicted for the indefinite future. For example, for all-year Eastern Daylight Time, zic now generates "XXX3EDT4,0/0,J365/23" where it previously generated "EST5EDT,0/0,J365/25" or "". (Thanks to Michael Deckers for noting the possibility of POSIX conformance.) zic.c no longer requires sys/wait.h (thanks to spazmodius for noting it wasn't needed). When reading slim TZif files, zdump no longer mishandles leap seconds on the rare platforms where time_t counts leap seconds, fixing a bug introduced in 2014g. zdump -v now outputs timestamps at boundaries of what localtime and gmtime can represent, instead of the less-useful timestamps one day after the minimum and one day before the maximum. (Thanks to Arthur David Olson for prototype code, and to Manuela Friedrich for debugging help.) zdump's -c and -t options are now consistently inclusive for the lower time bound and exclusive for the upper. Formerly they were inconsistent. (Confusion noted by Martin Burnicki.) Changes to build procedure You can now compile with -DHAVE_MALLOC_ERRNO=0 to port to non-POSIX hosts where malloc doesn't set errno. (Problem reported by Jan Engelhardt.) Changes to documentation tzfile.5 better matches a draft successor to RFC 8536 <https://datatracker.ietf.org/doc/draft-murchison-rfc8536bis/01/>. Here are links to the release files: https://www.iana.org/time-zones/repository/releases/tzcode2021b.tar.gz https://www.iana.org/time-zones/repository/releases/tzdata2021b.tar.gz https://www.iana.org/time-zones/repository/releases/tzdb-2021b.tar.lz The following convenience links are also available, although they may point to the previous release until the relevant caches are refreshed: https://www.iana.org/time-zones/repository/tzcode-latest.tar.gz https://www.iana.org/time-zones/repository/tzdata-latest.tar.gz https://www.iana.org/time-zones/repository/tzdb-latest.tar.lz Links are also available via plain HTTP, and via FTP from ftp://ftp.iana.org/tz/releases with the same basenames as above. Each release file has a GPG signature, which can be retrieved by appending ".asc" to the above URLs. Copies of these signatures are appended to this message. This release corresponds to commit 9ffa3f6e5019dfa7cfb5c0e4e8a84fa95adec704 dated 2021-09-24 16:23:00 -0700 and tagged '2021b' in the development GitHub repository at <https://github.com/eggert/tz>. Here are the SHA-512 checksums for the release files: 00fca7508cfbc42123065fe8087397c9dd2acbdda96f3bb0936187825348cf13538f1893f2d02bd8bfa3465427ca7a9a65451baffe39889bc58ba0a77a047806 tzcode2021b.tar.gz ca61d64af5ae791f337533c09d2b4f7caa645ecab7b9d13e9bcafc47c7c68535abe7c103c56bbd41d6bd913a8607f9c5187c8ce8a91b4891a750a643f89c8b51 tzdata2021b.tar.gz 326fb99666c8d5bb798a9c24d2869307620dce918d47fbedd7f765c91eb35ea44bf776f43cb00cde1944884150232ac6dcdc0194a0364e2d28f6470691cf9177 tzdb-2021b.tar.lz Here are the GPG digital signatures for the release files: -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEfjeSqdis99YzvBWI7ZfpDmKqfjQFAmFOX/wACgkQ7ZfpDmKq fjRKwA//RVH1mmf13Uz99KBQZMc/meVaYT1YSpMqilocZo1w+i+Omai7Aw/r9u1e lnwLQukqjpCH4TJWdq8VuloL5ojN1ImoZuIRYECWRHOShxMaS9DLkPRr4qA9Fxic hladneiIglVrnzQbG4pH0Vnu9Qakb6I+1um8lCNiJHng84y5KAOIcZu1m9O+A1F1 bdik8Ddxc4qBluUvcq9n9aqWSgDBvIyCYik6bOo3lOd5zP1rcjSr8VJ+15cAkH4X hU/igj9qloyqAmoOyJOzIIwv63T3Xg63rH/V2hJWyux54ayP4Kt8nZqLYA9V8gFI V/HL5qNafSYEqguO2H3hTwURc3Utini8Oa2Ou89Ih0hkO+nySacc0ZnhaunmX7Ip D5Oj6A8kssG0Uj5fZqpqUp1FeRbziAinSdwTOpRxdkdeHI6tfS0XVnRvRiFATfTu oh9107e3okwKAb2UPJtr8Oev0uU8rz8+EorN9/PqJv0n2c3I69NUv6TudFVHM8uB lwG3hUNtWWYpK/rzwX8AQkwTrOHMN3VJ94T8xaTm13/jtk6R/+GgSjXKC2C9XZG6 5uvi6et06WnRVRO+V5TwnQdfY85pe5nqRDLeo0clxdkAvx6fslLpz9YNacLV/Gn8 0UIGt9CBKjE+PU1F5w+O/5btA/1aTojuSpKscdzgQIzXTfDlTZo= =+McC -----END PGP SIGNATURE----- -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEfjeSqdis99YzvBWI7ZfpDmKqfjQFAmFOX/0ACgkQ7ZfpDmKq fjRYmg/9H3rMpV7uQdd+G2K0wybdzTH6vJiNQClWE1+wqCPh/L3e8kCbPIjSo7MF SFV/Pu4EDb9kjeA2ruEMYlLnpg5nTP7dYfFRsRDcQJ5Yw70luNImm1ipUkKr9o5Q oQqYFKzxvB0G1rE+/gMaxmCHtGaJnv0DEChhmAS5U4j48z71Fn3+UJIU9XPEaODD U1Fw62xDsxIlFKjZ9UvilhlVRMnnP5nK9hjrsFKn7OGbxYvkdaRoK5f3M+G5nGXh L9nZcE0cd/7zhD3+wlttcH+xw3b+5P+7sxMhucoWQXEl3KyIklh97fi7jzHBHz+s DRYLZv/yPoEp94QyCfaYdvWL/i4OX4/9YnXK3ruXDcEV2y8Zl7Wc70Ihxk3I2XAb S4YeMcb30uls93QUdSmuhpEEUWrS5e45OnPy9RnT/VnpCalxsukudSNRzuvivKZn TsPpf90VUtI9ncLZ4l7OoNVXSj5pJ6DS+V1nCesEQyfyFnFvgK/rogCZ0yt+Cosp zaXwBtGyOWwWsGgXHGdJoiQqt/FF8o387EL95vpFr9BRSdSQoKd6K9RrRIH9fuy/ nnpaksD86fx+WbdLMtbHzsZgCqL1RTGO+kc35Qlr3vqH02UAZiwC9l3DHS9SA01c MGDy9zaiLsL/8/lUV3AP31dEP1+DY+BXvdFhIJkmIceBUf7zl0E= =PO3W -----END PGP SIGNATURE----- -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEfjeSqdis99YzvBWI7ZfpDmKqfjQFAmFOX/4ACgkQ7ZfpDmKq fjSaPg//ZlKREhlxjnstpEl6W3x4sStpUrF/Kebp62txYoCjbK22EDnw4BbE0wFh BcIBGbfxioC2+1gAjG57LK0RzTqFPPuDA69qYIZFk+xLrREISDqrGHViLGkFEgm5 jEDamuGW59UoBdnu4Klp1JAd7hvYQYEbbVaIVsrUlAL99OTyujeA6QoZdIjM43eh jx4g1P/XuHBqJEH7d9kOM5tBCRvgFhhcu/s4vOvrfFibRHRimYBuPlep5nJ88bb/ UyCQ1oYIQucWtl+DOszICl/GTmuM33FMTeAX6OrlGxwON6KPI2qNzAaQVpK1apB/ qF9dTnOVP8pygW6HkiFwNOKx4mplB2V8f1eqLT9mfdOQsEWPRuDyUvejBIr/Hmww jHF1w9TX8FxND2KQmcfZNTlKqYcw1O8Vz4m+0UnDzNuLiZAsnTBTrfnKMnVrTOFt 1K6KKK+v5y4WYu+pE36cIBM2YxITEpD+YrRr7G1ilzVgRH5FRGCJsxJu0O+BO35z rv9qVnJz0xISMJs+qSdJT8v4W4Uc6+crnHjAc7T7eAin3i3y/GY/MA44isCACmhx +Rq165laaHXnqTOgQfHhGjigJoH3JCnDYUwg6q+fMMBU2eALkOs+IbgdfVB3hoyo UOlYH/A25nuI0PrRgUKsN6N2lrfPjq3bM4twDw33BOyGJ/LN88w= =aNBd -----END PGP SIGNATURE----- PS. If your tzdata parser does not yet support negative DST offsets or times past 24:00, or if it insists on a 'pacificnew' file that is no longer present, this release's data entries can be turned into a rearguard-format tarball that should work even with these older parsers. This is intended to be a temporary transition aid for these parsers. To generate a rearguard-format tarball, obtain the full distribution as described above, and run the command 'make rearguard_tarballs' on a development host. Or you can run 'make rearguard.zi' to generate a single file that can be fed directly to a parser that works like 'zic'.

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