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Re: [tz] Palestine winter time
by Paul Eggert Oct. 21, 2021

Oct. 21, 2021

On 10/20/21 01:47, heba.hamad(a)mtit.gov.ps wrote: > winter time will begin in Palestine from Friday 10-29 ,01:00 AM by 60 minutes backwards. Thank you for letting us know. Attached is a proposed change to tzdb, installed into its development version <https://github.com/eggert/tz>. We plan to have a new tzdb release soon. This change implements this year's transition, and also guesses that winter time will begin on October's last Friday at 01:00 in 2022 and later years, to be consistent with 2021. If this guess is wrong, please let us know as far in advance as possible, because rule changes trickle out only slowly to cell phones and computers.

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The origin of time zone regions
by Arthur David Olson Oct. 21, 2021

Oct. 21, 2021

A middling-length story with a small point. In the seventies and eighties, I helped develop two-dimensional PAGE* image analysis software. Black and white images had a thousand or so spots; the positions of the spots and their size provided information on the characteristics and abundances of proteins in samples. Step one was to get the positions and sizes of spots in a single image. Step two was to compare two images, pairing up the spots. Some spots would only appear in one image and have no pairs; in other cases, two (or more) spots would appear in one image where only one appeared in the other; one spot would be paired with multiple spots. The final step was to consider groups of images. For this purpose, there were groups of spots where (to quote an article on the matter) “each spot in a group is paired with some other spot in the group and no spot in any group is paired with any spot in any other group.” In the mid-eighties, work started on the time zone database. And time zone regions ended up being defined as being places where all the clocks agreed. The small point: the nature of time zone regions has less to do with chronometry or geopolitics than it does with gel analysis. @dashdashado _ * https://www.sciencedirect.com/topics/neuroscience/two-dimensional-gel-elect…

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Re: [tz] Pre-1970 data
by Stijn “Adhemar” Vandamme Oct. 20, 2021

Oct. 20, 2021

The “should timezones be merged when they contain identical offsets from 1970 onwards” discussion has been going on for quite a while on the tz mailing list. Still, contributions that I find insightful are still being made. Stephen Colebourne recently made this observation: > The key observation is that the segregation between these two groups > > of IDs *did not exist* until around 2014. It was only in 2018 that the > > ISO country rule was removed. > This change was reflected in the documentation <theory.html> as recently as 20/21 February 2019 < https://github.com/eggert/tz/commit/5f48dee82bc111b21f3610893e3b788e37396bce > < https://github.com/eggert/tz/commit/6176aefe79e83ddb8f255849b85c149f34d46aba > And Stephen made this spot-on point of analysis: > FWIW, it is clear to me that there is an aspect of imposing a > > US-centric timezone system on other parts of the world. The recent > > tzdb approach of focussing entirely on timezone regions makes perfect > > sense for the US, where region boundaries do not follow state lines, > > and ordinary members of the public need to be aware of whether they > > are in US/Mountain or US/Central. This simply isn't the timezone model > > in many other parts of the world. In places like Europe and Asia, the > > timezone is driven primarily by the country you live in - an ordinary > > member of the public in Iceland is never going to associate with some > > abstract timezone region stretching down the Atlantic that is not > > named, not legally defined and is little more than a random outcome > > based on tzdb's choice of 1970. Even in somewhere like Norway, an > > ordinary member of the public will understand that although they > > follow CET, their timezone is actually driven by their Government in > > Oslo. The brilliance of the original rule - "ID as needed for > > post-1970 data, with at least one per ISO country" - was that it > > seamlessly handled *both* models of timezone in one unified set of > > IDs. Removal of the ISO country part has completely destabilised that > > balance. > If I may throw in my two-penny, it would pertain to the documentation of this policy. Presently, <theory.html> does mention - that timezones are zones whose clocks all agree about timestamps that occur after the 1970 POSIX Epoch; - that 1970 is indeed a somewhat-arbitrary cutoff, but that moving it earlier even by a decade or two would impose significant challenges, due to the wide variety of local practices before computer timekeeping became prevalent; - that pre-1970 clock transitions are recorded for location-based timezones, but that the database is not designed for and does not suffice for applications requiring accurate handling of all past times everywhere; - that the previous “at-least-one-timezone-per-country-with-officially-designated-ISO-3166-1-two-letter-country-code” rule is dropped for this imposed too high a maintenance burden; and - that some information outside the scope of the database (implied: pre-1970) is collected in a file backzone that is distributed along with the database proper, but that this file is less reliable and does not necessarily follow database guidelines. What astonishes me in this issue is that high-quality information is being removed from the database proper into backzone, without this being mentioned in the documentation <theory.html>. Granted, <theory.html> does not explicitly state an “at-least-attempt-to-get-monotonically-closer-to-the-truth-with-increasing-versions” policy, but one would think that’s implied in maintaining a (versioned) database, unless explicitly stated otherwise. The other way around (moving information from backzone to the database proper, e.g. when historical information is double-checked and confirmed to be in accordance with database guidelines) is totally acceptable without mentioning in the documentation <theory.html>. Indeed, even though I know that correcting pre-1970 data is not the priority of this project, I’ve seen some great sluthing of historical time zone offsets presented on the tz mailing list in the past, and I kinda assumed that the results of such research found its way to the database proper (or backzone when doubts remained). In my opinion, removing high-quality information — thereby having correct offsets changed into incorrect offsets in information systems that rely on the tz database and keep it up-to-date on the default settings (which disregard backzone) — should cease, and should preferably be undone where such damage has already occured. Seeing how much problems pursuing “fairness” under the new rules causes, perhaps it’s worth reinstating the previous “at-least-one-timezone-per-country-with-officially-designated-ISO-3166-1-two-letter-country-code” rule, either officially or unofficially. (And for what it’s worth, this comes from someone who generally tries to avoid relying on country lists such as ISO 3166-1, due to strong political belief in the desirability of independence or at least increased self-governance for several countries/regions currently lacking an officially-designated ISO 3166-1 two-letter country code, including Flanders, Wallonia, Scotland, Catalonia, Basque Country, Canary Islands, Tibet, and others.) But alternatively, if this project persists in its “removing-high-quality-information and merging-for-merging’s-sake” policy, then at the very least this should be mentioned clearly, unambiguously and conspicuously highlighted (bold, bigger font size, bright but fully saturated background colour, following an animated warning icon, the lot) in the documentation <theory.html>: PREVIOUSLY OR CURRENTLY CORRECT PRE-1970 OFFSET INFORMATION IS > INTENTIONALLY BEING CHANGED AND/OR MAY INTENTIONALLY BE CHANGED IN LATER > VERSIONS OF THE tz DATABASE INTO INCORRECT OFFSET INFORMATION for the > braindead reason of merging timezones for merging’s sake. > USERS MUST NOT RELY ON UNDISPUTEDLY AND UNCONTESTEDLY CORRECT AND VERIFIED > OFFSET INFORMATION REMAINING CORRECT in the database proper, except for > timezones that have post-1970 particularities which prevent them from being > merged with foreign timezones. (And even then — who knows what the > coordinator-maintainer will come up with next…) > Information systems that rely on tz for offset information, including for > pre-1970 datetimes-with-timezone-identifier, ought to pass this warning on > to their users. > — Adhemar

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Palestine winter time
by heba.hamad＠mtit.gov.ps Oct. 20, 2021

Oct. 20, 2021

Dear Sir, I’m Heba Hamad .I have been appointed as a focal point by the Ministry of telecommunication and information technology (state of Palestine) to communicate with you. We would like to inform you that winter time will begin in Palestine from Friday 10-29 ,01:00 AM by 60 minutes backwards. Kindly find the attachment below that includes the decision of the Palestinian cabinet. With Respects, Sent from Mail for Windows

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Palestine winter time
by P Chan Oct. 18, 2021

Oct. 18, 2021

http://wafa.ps/Pages/Details/34701 https://www.facebook.com/wafagency/posts/4457787417632704 Palestine winter time will start from midnight 2021-10-29 (Thursday-Friday).

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[tz-announce] 2021d release of tz code and data available
by Paul Eggert via tz-announce Oct. 15, 2021

Oct. 15, 2021

The 2021d release of the tz code and data is available. This release reflects the following changes, which were either circulated on the tz mailing list or are relatively minor technical or administrative changes: Briefly: Fiji suspends DST for the 2021/2022 season. 'zic -r' marks unspecified timestamps with "-00". Changes to future timestamps Fiji will suspend observance of DST for the 2021/2022 season. Assume for now that it will return next year. (Thanks to Jashneel Kumar and P Chan.) Changes to code 'zic -r' now uses "-00" time zone abbreviations for intervals with UT offsets that are unspecified due to -r truncation. This implements a change in draft Internet RFC 8536bis. Here are links to the release files: https://www.iana.org/time-zones/repository/releases/tzcode2021d.tar.gz https://www.iana.org/time-zones/repository/releases/tzdata2021d.tar.gz https://www.iana.org/time-zones/repository/releases/tzdb-2021d.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 4de3d7f2499328c97e652242a36fed9523741d12 dated 2021-10-15 13:48:18 -0700 and tagged '2021d' in the development GitHub repository at <https://github.com/eggert/tz>. Here are the SHA-512 checksums for the release files: dbd7e3df02a11676600aa7efa14592feb2ac9ab5807b0d395e0c29ff1ed4a31580120287df9fe0c65a78162157dcd31d9fbe90a2a93bfd891d59ae3668a3adda tzcode2021d.tar.gz e25e85679256cfa57072cc8902aad1ca1df5ddc4a06844ca38bd57c8b5ad386e38303654dc85525f4fb470a924db4deb3576827a14d3ff87f4a1c679414b95c9 tzdata2021d.tar.gz 6ccb3ed6ebf35643cb49d503f18b7c66957de098f41870fd14ac37489b0931abd6d3e7bf5c2797e69f56f44b31ff9f9068ffa40f5aa29260ecda9d0aac878103 tzdb-2021d.tar.lz Here are the GPG digital signatures for the release files: -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEfjeSqdis99YzvBWI7ZfpDmKqfjQFAmFp6ekACgkQ7ZfpDmKq fjQtmBAApD1Am4P0gbEECXOABxrnE258QrPRqPhupj45gW0kMD5BehW+yO2oIzOU zDmgLbWyG5CmbD2lSt2fq1mZKhfqYD2J4QJlwwiPGHriNKZZCVIQniXZVRFUzQz/ oObtIzNm5mgR6OUhWDcbzYZsa10eJ7HTMrDOGViZ7T1DyLj5yobSXqkC/Q/ZlEvM Vpnl9nDieey2GgXvobfpR+Bby6NB26Pojjab9Mbw9jyRtcvnf6GmdBn6v4aoDwKc ZUqcb9qjv7NXnN5o9nCUSK7/ad+RoVZJAVDe84Quj1Vn8ydfZ0/1+i6bF3mM6Bpi I3riuPKkv7AHW2iRgZPnnqH7U+X32gb55/+WleokkasZj7e8i1QjJW7L0b91YOHN USz1McquYNsh/n9IDph4Zw1tBpbmLYAy3HQPaR6OzO8fc9paw5nsoics/5fQ5WoZ 2T2EavJfa045XKxwzd57w9YthQgW27Ep6UMpVCEGjYCBfVt8MfmiB787apGJdeJj NeVaKfSfpE4PTWvrtfTXPCIVIbIhlA5UUXyhEBXrMJw/FVxf8rAHGi/zvmrgl48X iY/xMG4yWpUYwZqWG0NBeGE0tvj8Yj2NagWj/UnGXcte3MvgmjkFSnKhj+UZrcA+ 1ehgE8pGicWEl0xl7uW6uwJ1IgWBMHYIkxpslJdTru+nnfbBIaA= =Bvd6 -----END PGP SIGNATURE----- -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEfjeSqdis99YzvBWI7ZfpDmKqfjQFAmFp6ekACgkQ7ZfpDmKq fjTbSA/9HBEpib2dXzZg06u4WuVwFEbzu1AUblHm7I9PAzoxtTvJJqH0dMCrHDlj wldeHGclbBxLq8wF33Ajh7bvgISDhmjQCm/ux7nS0ctRnPkV4Pj2j6lsfk/gYVIB agFefLTTrdHaIrPxZ9TK7c63X+6HMfFDnE+nOrJXimls/gW/Xu/VeMDtngrCIoB3 JTSbPePbaSlA+NMn+RRhfb6jlw/Slbm7n5Zpf+VSZs2HN4+bNpHuFLbl5oMbPOrQ C+va/yKJXrNYroGOfIlz/ZnM24ZGDterLh9BBLe+zy3Ni+dhuH0x406C8zkZXSDu U1BZvHK3f84beSF0H1SbkGyjkfVSIol1o2p69mMdcyZzewng3n+MLB8lNxyMkmyk f8cTKviE0V+xoEe/yV8+0+uDhli+oLMudqNGy8eCRNgrnRkCsP513LMX73bagohQ xjtBd+cp2VSzhV4vXsJJE7mIwzofnZaGqdR/jyHND+4gx80TQo8Ftc29wRGbwCCI WU37r17EmcOPg+emOciIf8nYCPnIvKGBBZ0UcCEuvaZXXYhyg+2c82z7A+bIPZaS 6wQZhqptoWB07tJOMxcgCCV7I1fT8+GLlLLlJQXladooOa06mVzsFk8VlUX4PRl3 bIQGNgqRtoE/RnhbxgD0A4ToYUqdMvYzcoCGIGpg/4zmyFZWcaY= =NgZm -----END PGP SIGNATURE----- -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEfjeSqdis99YzvBWI7ZfpDmKqfjQFAmFp6esACgkQ7ZfpDmKq fjSsWg/+NCtwn4E06FCtkR08EV0R8uG4xI6HyQc8JsB5DiFkt+evge2Bu+De03y5 nUJ1eaWbg27MLMfdYI7q5tET9G5RRcFUSZx5Zpj+Bv++KHEz7QSB5ZajE2n2qi93 AkXtFEQn8n0sCKbxdpikiUtKyZbIhcBZkzpAVU3sDdphoLUJFI2YPUCwNL5sPnzH 9pI9/iXCvu1mDW0Mg+mdBO6BuMVmTZneSJ+qtWVRvDPBvWJu8vDr16YiNaTYXkX6 atnvTDmjc3RP5DAjFzItBjsZWcLfrWWQ9WezYXWGDmJS+ijxSH0eYAUfXdHESMMd ggNwlsYZumla1p8yGmHP7YkUynds2hZYV8ySCZhfaCjq/AYANs2hzYLIY5reQ6mJ XxRoGOECc2uCmIVwFjYAALghW0GnDAy6M/l+qgzSxAr92Y0GdlFSdv8yWvIBYPyg /gFKrS+IkLHPJEF5vcpxCpCJC2XR2lJLAzoAgLUc14kD5enmVUjJzia8CpKahq2S argJwtnUl+pZT5QLfOSC46jG2o+RnhSarPSNb21cs+eNnPMA31aXDIRrGDCJ6UXf nRAU1t7eq4bbb/cvEGgJ9ZCfoQpBhYT4QO8as4JXnzkHrB7PuUiqw2sOXixF6H46 MSKRQq/uWI6XiAbXpUDFh67EeH/U1YkR8mx67Uii6pcGLvK2ptM= =Brw7 -----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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[PROPOSED 1/3] Document that -00 means local time is unspecified
by Paul Eggert Oct. 15, 2021

Oct. 15, 2021

* tzfile.5, zic.8: Document longstanding practice in time zone abbreviations. This better matches draft RFC 8536bis. --- tzfile.5 | 4 +++- zic.8 | 3 +++ 2 files changed, 6 insertions(+), 1 deletion(-) diff --git a/tzfile.5 b/tzfile.5 index 74564cb..e2f11b4 100644 --- a/tzfile.5 +++ b/tzfile.5 @@ -118,7 +118,9 @@ and serves as an index into the array of time zone abbreviation bytes that follow the .B ttinfo -structure(s) in the file. +entries in the file; if the designated string is "\*-00", the +.B ttinfo +entry is a placeholder indicating that local time is unspecified. The .B tt_utoff value is never equal to \-2**31, to let 32-bit clients negate it without diff --git a/zic.8 b/zic.8 index 3727922..89fc827 100644 --- a/zic.8 +++ b/zic.8 @@ -559,6 +559,9 @@ alphanumeric ASCII characters, .q "+" and .q "\*-". +By convention, the time zone abbreviation +.q "\*-00" +is a placeholder that means local time is unspecified. .TP .B UNTIL The time at which the UT offset or the rule(s) change for a location. -- 2.30.2

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Kiev >> Kyiv
by Pavlo Komendant Oct. 12, 2021

Oct. 12, 2021

Hello, Could you please amend the Ukraine capital in the time zone? Kyiv is the correct spelling of the Ukraine capital https://en.wikipedia.org/wiki/Kyiv Thank you! -- Pavlo

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Daylight Saving in Fiji Islands
by Jashneel Kumar Oct. 11, 2021

Oct. 11, 2021

Dear Support, Please note that there will be no daylight saving this year. Appreciate if the same can be reflected in your system to ensure that the time does not change. Looking forward to the confirmation. Regards, [New_VF_Icon_RGB_RED] Jashneel Kumar Manager Data Networks & Services Jashneel.Kumar(a)vodafone.com.fj<mailto:Jashneel.Kumar@vodafone.com.fj> Vodafone Fiji PTE Limited, 168 Princes Rd, Tamavua, Suva, Fiji Islands www.vodafone.com.fj<http://www.vodafone.com.fj/> Together we can [Vodafone] ________________________________ The content of this email including any attachments is confidential and may contain information that is proprietary and privileged. If you are not the intended recipient be advised that you have received this email in error and that any use, dissemination, forwarding, printing or copying of this email is strictly prohibited. If you have received this email in error please notify E-mail Administrator on info(a)vodafone.com.fj Please also destroy and delete this message from your system. Vodafone Fiji PTE Limited does not guarantee that this message is free from computer virus or any other defect. The reader accepts full responsibility for taking defensive and counteractive action needed to rectify the computer virus or other defects caused. Vodafone Fiji PTE Limited : Private Mail Bag, Suva, Fiji | Telephone : +679 3312000 | E-Mail : info(a)vodafone.com.fj Please consider your environmental responsibility before printing this e-mail [https://www.vodafone.com.fj//images/default-source/logo/logo-2x.png] Vodafone Fiji PTE Ltd <https://www.vodafone.com.fj/>

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Typo in zic(8) man page
by Jonathan Wakely Oct. 8, 2021

Oct. 8, 2021

The description of a RULES field in a zone line says: "giving of the amount of time to be added" The first "of" looks like a typo.

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Classifying IDs
by Stephen Colebourne Oct. 8, 2021

Oct. 8, 2021

Following on from the previous thread [1] I wanted to try and classify the IDs we have, which may or may not identify missing IDs. Again, please avoid talking about pre-1970 data at this point. Obsolete ------------ IDs that are obsolete and should never be used. They date from many years ago whe tzdb was just starting. Yet these still do appear in downstream UIs even today (of course UIs should not use the tzdb ID list, but in reality lots do). Examples: Portugal, NZ-CHAT, Navajo, Libya. Proposal: Provide 3-6 months notice, then move obsolete IDs to a new file "obsolete" which downstream projects are strongly encouraged not to include. (I would argue that the time has come to properly remove these IDs, which are very inconsistent in terms of which are provided and which not, eg Portugal, but not Spain) Deprecated, same location ------------------------------------ IDs that have been deprecated with a single clear alternative ID being provided. Both IDs represent the same physical location/city. Spelling changes: Asia/Katmandu (replaced by Asia/Kathmandu), Asia/Rangoon (replaced by Asia/Yangon) ID structure changes: America/Louisville (replaced by America/Kentucky/Louisville) Proposal: Ensure all of these are in `backward` Consider: Is there any way to move these IDs to the obsolete file? Maybe after 5 years? Or do we just accept backwards compatibility restrictions on these? Legally described mega-zones ----------------------------------------- IDs for locations where a federal or supra-national body defines rules, eg the EU or US DOT. Examples: US/Mountain, CET, WET Consider: Can we write down a rule to identify when something like this should be included? Then move the matching IDs to the main files (eg. are the EU and US DOT the only two examples here?) Regions ----------- IDs for abstract regions that have had the same wall clock since 1970. Examples: Europe/Berlin, America/New_York, Africa/Abidjan Proposal: Ensure all of these are in the main files. Consider: Should there be new IDs for each of these abstract regions to indicate they are a separate and distinct concept? eg. "Region/Berlin". (Maybe something to consider in future threads as it isn't clear what the benefit of doing so is without considering pre-1970 which I'm still trying to avoid) Non-region locations --------------------------- IDs for locations that are not region IDs. Each ID will have the same wall clock since 1970 as one of the region IDs. Examples: Europe/Oslo, Europe/Amsterdam, Atlantic/Reykjavik Consider: Can we write down a rule that covers which IDs are included here? And therefore when a new ID can be added to this set? If we can define a rule, then these can be split so rule-following IDs are in the main files and rule-breaking ones are in `backward` (although ideally they should be separate from the spelling changes). Obviously, we can say these IDs only exist for backwards compatibility, but that seems like a weak justification, and doesn't tackle the issue of when a new ID would be added to the list (which has been a point of tension). As is well known, I think the obvious rule is that the IDs follow the ISO-3166-1 standard (rule: one ID per ISO code, additional IDs may be added where clocks have diverged since 1970). Using ISO-3166 can be justified by IANA domain policy [2]: "We are not in the business of deciding what is and what is not a country. Instead, we employ a neutral standard maintained by the ISO 3166 Maintenance Agency. Our policy is to create new country-code top-level domains when the country or territory is listed on the ISO 3166-1 standard." As per the previous thread, these non-region location IDs are actively used in downstream business applications, and it is not OK that only works because tzdb happens to have IDs for backwards compatibility. There needs to be a better justification than that - these non-region locations need to be fully supported, with a consistent rule used to define what is and is not fully supported. Fixed/etc type rules -------------------------- IDs with a fixed offset Examples: GMT, UTC, Etc/GMT-9 Proposal: No change, retain in the main files unless a particular ID is considered obsolete or deprecated Are there any more classifications I've missed? Stephen [1] https://mm.icann.org/pipermail/tz/2021-September/030857.html [2] https://www.iana.org/help/eligible-tlds

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Downstream use of 2021c
by Philip Paeps Oct. 8, 2021

Oct. 8, 2021

Since the tzdata 2021c release removed most of the controversial link changes, I wonder how other downstreams feel about importing it. I spent some time this morning looking at the downstreams I know about. FreeBSD has 2021c in main but is still on 2021a plus Samoa and Jordan in the supported stable branches. Debian is in the same state as FreeBSD. NetBSD, OpenBSD and Ubuntu are on 2021a + Samoa and Jordan. Fedora is on 2021b. CentOS is on 2021a. A casual glance at other Linux distributions shows they are either on 2021a or 2021c. I am not familiar with their support models so I can't read anything into that. Python "pytz" seems to be on 2021c. Python "tzdata" seems to be in a similar state to FreeBSD, though I'm not sure I'm interpreting the release model correctly. I know Paul G is on this mailing list though. As far as I can tell, PostgreSQL is still on 2021a without modifications for Samoa and Jordan. Tom will correct me if I'm reading that wrong. I don't know enough about PHP, Java or any of the other well-known (let alone less well-known) downstreams to figure out what they're doing. This is looking terribly fragmented. Spare a thought for a hypothetical engineer tasked with debugging a Java application on Debian with some Python scripts on Fedora talking to a PostgreSQL database running on FreeBSD... While discussions on this list appear to have become more constructive, it looks like we're still lacking a clear consensus on the long-term direction. I feel that 2021c is a pretty reasonable compromise and would be willing to merge it to the supported FreeBSD releases. Is this something other downstreams would consider too? Alternatively, can we reach an interim consensus for a 2021d release that we'd all be willing to merge? Philip -- Philip Paeps Senior Reality Engineer Alternative Enterprises

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Use cases for source data
by Gilmore Davidson Oct. 8, 2021

Oct. 8, 2021

Stephen Colebourne's recent attempts to define requirements and use cases for tzdb got me thinking about the source data files. There have been several discussions over the years regarding the intended stability of the source format, separate from TZif binary files. These generally arise when the answer to a data query is "use this special compile-time flag". The most recent example is from Stephen at http://mm.icann.org/pipermail/tz/2021-September/030561.html The subtlety is in how the data set is consumed. While many downstream > projects use the makefile, not all do. A significant portion of > downstream users make use of the source files directly, with their own > parsers. ie. there is no ability to use a compile-time option. Those > parsers are not setup to use backzone even if it were a valid option > I think some of these discussions come about because there's disagreement about the intended use of the source files. The impression I've got from this list over the years is that the source files weren't intended to be a stable API; only the compiled TZif binary files were intended to be consumed downstream (and in later years, the .zi text representations). But many projects do use the source files as their primary interface, leading to tension when the format changes. So this is my attempt to list the use cases that people have for the source data files. This could prompt a wider discussion about what counts as a defined, stable interface for tzdb. Not every consumer of tzdb data is relying solely on the pre-compiled binary files. NOTE: This is a separate issue from the recent pre-/post-1970 data discussions. I'm trying to stay away from wading into that topic. ----------------------- Consumers of the source data text files: 1) The zic compiler for producing TZif binary files and .zi text files in an official tzdb release. 2) People reading the file comments to understand the history of certain zones. 3) Libraries/projects that need to parse/compile the data into a different representation than that provided by zic. This is often, but not exclusively, to preserve the distinction between Link and Zone entries, either for API or data compression reasons. 4) Data analysis or visualisations that care about knowing the higher-level Rule definitions ("transition on the last Sunday of October every year") rather than the exact transition timestamps for each year. 5) IDE or text editor plugins that provide syntax highlighting for the source files. All of these are based just on my own experiences and from lurking on this list. Any corrections/additions are welcome.

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Re: [tz] On ISO country for timezones (Re: Classifying IDs)
by dpatte Oct. 7, 2021

Oct. 7, 2021

I believe you are missing an important part of this discussion.There is a strong need for a repository of pre 1970 data, especially for historical research applications. As this is the only tz database, tz has also become the main database for this older data.For any populated place on earth researchers need such a repository. If I want to add the pre 1970 tz history for Ottawa Canada where should it be stored? Since it is called tz, and it also has other pre 1970 data, tz seems the appropriate place.But if no simple method of adding open-ended historical data is negotiated here, then the only other option is to fork tz and work on it as a separate project.Secondly, since the number of locations that could eventually be supported in a historical tz database is potentially very large, it cannot not be micromanaged, and this suggests that each historical zone should use an international standard for naming - iso - for simplicity and clarity.Canada/Ontario/OttawaAre we going to have two tz databases, or just one. That is the question here.Sent from my Galaxy -------- Original message --------From: Steffen Nurpmeso via tz <tz(a)iana.org> Date: 2021-10-07 09:35 (GMT-05:00) To: Stephen Colebourne <scolebourne(a)joda.org> Cc: tz(a)iana.org Subject: Re: [tz] On ISO country for timezones (Re: Classifying IDs) Stephen Colebourne wrote in <CACzrW9Cau-q2e+yoBcg=7Rztu19zZN582Xca9ZMYbz=H_0iOpw(a)mail.gmail.com>: |On Thu, 7 Oct 2021 at 07:08, Watson Ladd via tz <tz(a)iana.org> wrote: ... |I agree with backwards compatibility. The primary concern here is |whether an ID is considered deprecated or not.IDs shall be stable and not change at all. At maximum they shouldbe moved to backward, for example if a zone is renamed (which mayhappen for example for Ukraine in a not too distant future, ifthat is still necessary then, and it looks as if it would be).I would always have been all for making infinite stability of IDsa documented assertion.Even if not, your "six months" claim is nothing but an aggressivestatement. I think this entire thread is shadowboxing and noisefor nothing.Looking at the interface of your JAVA framework i think getID()should simply return the correct ID, which may be a link if it isone, and just in case this is not what getID() already returns.In my opinion there are only two problems with IANA TZ and howPaul Eggert manages it as a maintainer. That is the same PaulEggert who contributes to this software since 1995, an astonishing26 years. Corroding the maintainership with a continuous streamof noise is disgusting.The first is combining of datasets to equal-post-1970 bundles,which is going on for many years. But the data is there, it is inbackzone, and everybody can easily install a complete TZ DB onone's own request. Yet noone did, even though many packagers areon this list. This is schizophrenic. But maybe it is onlybecause of black and yellow people do not matter as much as someblue-eyed white people from northern Europe, which does not trulycome as a surprise given the audience who possibly reads this now,and given the fact that colonianisation ended only about 55 yearsago, and de facto was only turned from armed political to armedmaterial oppression.The second is that documentation did not follow suit the codeimprovements, as has been recently shown for tzselect(8) and the-t option. That tzselect(8) uses the administrative zone1970.taband not the end-user-preferrable zone.tab is a different thing.If you want to enforce upon the maintainer of the TZ database thatthe pre-1970 data is joined back into the normal data, or that"backzone" is splitted into "backzone" and "unreliable", and/orthat "backzone" is included by default, and/or that "ZFLAGS='-r@0'" is made default, then create a thread and try to gain enoughhums, but please stop this subversion by spreading uncertainty andthat even upon topics which never were under discussion as far asi know, and i also read this list for a decade now.It must anyway be said it was nicer once i only had thedistribution and did not know about the list :)Ciao from Germany,--steffen||Der Kragenbaer, The moon bear,|der holt sich munter he cheerfully and one by one|einen nach dem anderen runter wa.ks himself off|(By Robert Gernhardt)

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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

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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.

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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

legal status of information on TZ database
by nadir altinbas Oct. 5, 2021

Oct. 5, 2021

Hye, Is there a RFC document in which "explain rights and responsibilities of icann TZ coordination , about to solve regulation problems become from legal conflicts that third party person or company got and use of changes on TZ database country data by damage of their economic contracts agreement ?04.10.2021regards, Nadir Altinbasnadiraltinbas(a)yahoo.com n.altinbas

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Re: [tz] TZDB use cases
by Hal Murray Oct. 5, 2021

Oct. 5, 2021

Stephen Colebourne said: > So, it turns out that there is, I believe, a critical difference here between > the US view of timezones and the European one. In the US, timezones do not > follow the boundary of the whole country, nor even States. In Europe, by > contrast, timezone boundaries are very much driven by country boundaries. There is another interesting difference. US borders are stable. Czechoslovakia and Yugoslavia have split post 1970. Did all the pieces retain the same TZ info? I think small regions on the France/German border changed sides after WW 1. Are there others? Anything similar post 1970? Have any US/state borders changed when rivers changed their course? If so, do any people live in the regions that changed and/or did anything interesting happen there? -- These are my opinions. I hate spam.

3 3

32-bit section missing transitions in 2021b
by Daniel Fischer Oct. 2, 2021

Oct. 2, 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

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

Oct. 1, 2021

The 2021c release of the tz code and data is available. This is a bugfix release that addresses compatibility problems reported since 2021b came out, notably those reported by Stephen Colebourne. Although this release doesn't address the deeper issues about maintenance philosophy and procedures (discussion of which is ongoing), it does merge in changes to address what Stephen reported was his primary problem with 2021b. This release reflects the following changes, which were either circulated on the tz mailing list or are relatively minor technical or administrative changes: Briefly: Revert most 2021b changes to 'backward'. Fix 'zic -b fat' bug in pre-1970 32-bit data. Fix two Link line typos. Distribute SECURITY file. This release is intended as a bugfix release, to fix compatibility problems and typos reported since 2021b was released. Changes to Link directives Revert almost all of 2021b's changes to the 'backward' file, by moving Link directives back to where they were in 2021a. Although 'zic' doesn't care which source file contains a Link directive, some downstream uses ran into trouble with the move. (Problem reported by Stephen Colebourne for Joda-Time.) Fix typo that linked Atlantic/Jan_Mayen to the wrong location (problem reported by Chris Walton). Fix 'backzone' typo that linked America/Virgin to the wrong location (problem reported by Michael Deckers). Changes to code Fix a bug in 'zic -b fat' that caused old timestamps to be mishandled in 32-bit-only readers (problem reported by Daniel Fischer). Changes to documentation Distribute the SECURITY file (problem reported by Andreas Radke). Here are links to the release files: https://www.iana.org/time-zones/repository/releases/tzcode2021c.tar.gz https://www.iana.org/time-zones/repository/releases/tzdata2021c.tar.gz https://www.iana.org/time-zones/repository/releases/tzdb-2021c.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 d2c79c4bc68c02b785990a6d4eb161770058078e dated 2021-10-01 14:21:49 -0700 and tagged '2021c' in the development GitHub repository at <https://github.com/eggert/tz>. Here are the SHA-512 checksums for the release files: 9ed7677744058c58656b47d77d464bad6ef503f2892b53c6abe694e68e73fa123dfc5c11bbcbbb7798f0a6bf1da72b81f8f1c63670839b967e15e58d6d36adad tzcode2021c.tar.gz e8de3a17c38f530b2ec39605699742dd32da5ee92ecf64accaaa5b012a1dac51d1f594adc52660602c3425016520346ab6ad614fa475eb310e17ccdcae93e6ca tzdata2021c.tar.gz a6a86b5b84353c952eec6192222f95f348900dfb414f2dd205fa245515a0f240ba50eab83999f2a5c2cc8e3547406c111aacd96ff9043364d679c86a5e4b0794 tzdb-2021c.tar.lz Here are the GPG digital signatures for the release files: -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEfjeSqdis99YzvBWI7ZfpDmKqfjQFAmFXfJgACgkQ7ZfpDmKq fjReHA/+LiurpLRdXhwkSuhwUKlAQTKmry3F2/zFyobqi+EEEd7naiJIiQbIlScv aZ0cr6Tpq+oP0L8K0EaLMnz9vvb4qd7M3LLGOcrsML8/z0IigMBaA4c8L/Ep3ACa nsLTKESq6bYUJ2SbaFcCFx4KqwA8UEmfhzrPbNxeb3SVgrI1KwUWkpuTCOpewu+g ZYCVO7mFRhLuaD3wCbErtw9g7vQHyHGPGfTDHyc6lPrEbIaY1gwgl6GwBTmJD72a przvxg/0r0X+ZzHH9GZRQaWSDEGXYUdnIwrnS7zwDNk33WO3VwgLWiX2QMGJwiTe wPku4mnGkRhwQLzG+kJxpWe3DJ9/iKFVvxvS3/5RSN1mnELA6xcGOWMTL9cawlwo RkpyN3bLow/9u3wcW2QSrDhCTlGl5kUeK7Qbi20Rji9q2NIO0zrJ732pdr0PgyCN NeuO0YnHUW0bvGO7IMv0JfhQ+VbjB9yAzOg7D2bR2dSVm++38bR8umI757xU/6sT /CTIpmfP67FsXmtg98PbO6rEmoLr7Y/t+JYi/AwzvoHeFS5CAGs9xnTpdk+dBhjh wjLegKDtLZpIUppH9AkJ/T9MAVsfFpsLa2EnteF3LuYZhFTXzLJj3uo3l6Ji0eMZ RRy1jZAxnZ02EoLRIloezzST4pmxIurepluyzvTXVBBuXcoqDk4= =S2t+ -----END PGP SIGNATURE----- -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEfjeSqdis99YzvBWI7ZfpDmKqfjQFAmFXfJgACgkQ7ZfpDmKq fjR/9g/+LOFIZC6n1xKEMn95PsJx2e+zQ4m2/MG1L1KKZdR6kYnvQHL3hh+dXLdr cKRoB6k4AZDaCl7NZDZ8iKgm0nrXnG4/dVEfVOeJn9VHdRyYZ4sg68Nij0yHheRN fcX/ikKwmVaszwj8t+zTmetZOxlJi1mdLyZaQYgBZuM+8Aj+AnB3QUT00yP3j5xP lZgAToYXyLg8KweHnCuD41ZzU8AmsUU2GSfbTryez5lSGnhTsI+tNFtk5w+2fWZZ C0ZAskT//F2k6viFBozeBoodTs955mPKuzyWte6WyhQOTVUySuaeeAU7Dc9SK1k2 nNMTDeQyR78CL39D/X0qmINAif9YKqQ1k0fJFHH1K+pSbhtw0TaqZarQ7JRQnZpC XSIJ9PwpuLLb4k0pBUWYS+r1bZDWrymmgvDO4uNFRFC8LWR4pKyWZ8k34IYQndaV otWbBcThgyz8JJk5mrf113j7qQ3AYiC/y1lVtBpCXpOy1LzYGSTDUqUoHeib8ToD Q3wD1UTPPlo1nh47+cx/Fq1MasdB4MF/OwX7w33nV7TbYgNOHHjb5ROgf7unbaqM 96rtJDRFXFnnPtDOES3xtF4IEEXeoqx1q6AEEcEBBmkCc+DQk5AvW64JwluKn4b1 XSDP7AuXex+wJKffa/7I2KyNLNiX8aLQcnvVsD9cqV4hComR3O8= =LtLe -----END PGP SIGNATURE----- -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEfjeSqdis99YzvBWI7ZfpDmKqfjQFAmFXfJoACgkQ7ZfpDmKq fjTWQA/9Geo9i7m1YlBbU6xJQFyT2AVTTeCgA3wnQOc7VXj5Sy8/7JBU/AJW4Vmi iaTE+XZJU8ghslbdwkyEwoFcZ+4dT8qtjIDSaJ989LV8zpL0MPjgQPdYnh9egaGo qUQBXBcBzzK6giDut7vYcldf5YbK8AAv/ApvVyqL9JjdjbE2P3/juPAHUBUTxHIl bGrnRKbXIeqHB2MGgNZcby4HyblR+BCue3r9kN7Jq0kzETHG8UDeEDeHpL9x9DIq QIYpCiiuMvT7FZR4vNlQg5oBm6Tjz47BEWlvpDQcZHSAgXVrMOTds7uameG72DRW TtEGbozg2LQS3RKHn9mN0GK505d/qiSgrR/AoP420g6xa7d49Orz5qTcE4hUUqQ6 /YA2/3LqqCXeNep/BjwDvsvSTN8TKF4y0iF26Ie2BWRCnI377tT/76NncWaXRT3f k4X2qdIu/6EGle9kleanIZvet3/yavwpOXpgjcMPBwa1RoZDcH2/YSTd0uFhBXLw FTgJ2LKU1d7HVn5VR3t0z1ltjTjv5kjAt+/E/xdANN/vY27ef6yOMp9Mq4z3Pp9Y cUtwwM0aXchlCcomOhoKOShW/j8hFFlIX3pEEAQOhvDS4t7zw0x18+737Fi5diY6 5GUcyKs0sgIkGcAco1qZXd6vvR61ekq7rgMANpi8g9H5igjt5TM= =23yb -----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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[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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Discussion on LWN on the equity controversy
by Sanjeev Gupta Oct. 1, 2021

Oct. 1, 2021

Folks, On Linux Weekly News (which actually is about more than Linux), there is a summary and discussion on the issues raised here. LWN has a very high signal/noise ratio, I find. I have been a paid subscriber for a couple of decades. Here is a link (LWN allows subscribers to generate a link to an article for viewing by non-subscribers, all content s free after a week): https://lwn.net/SubscriberLink/870478/9dcc3764b87edfaf/ Thanks, -- Sanjeev Gupta +65 98551208 http://www.linkedin.com/in/ghane

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Dropping coordinates from zone1970.tab?
by Aurelien Jarno Oct. 1, 2021

Oct. 1, 2021

Hi, With the recent changes, geographically distant locations share the same timezone and the same coordinates in the zone1970.tab file. For instance Antarctica/Syowa is a link to Asia/Riyadh and appear with the same coordinates in the zone1970.tab file, while they are more than 10000 km apart. The zone1970.tab says: "This table is intended as an aid for users, to help them select timezones appropriate for their practical needs". I have the impression that the coordinates in that table do not anymore aid users to select appropriate timezones, so I wonder if they should just get dropped. Regards, Aurelien -- Aurelien Jarno GPG: 4096R/1DDD8C9B aurelien(a)aurel32.net http://www.aurel32.net

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[PATCH] Formatting of NEWS file is inconsistent in 2021b
by Paul Ganssle Sept. 30, 2021

Sept. 30, 2021

All previous entries in NEWS have a format of headings following nested levels of indentation — the release is unindented, then subheadings with a 2-space indentation, then the contents of each subhead are blocks indented with 2 spaces. In the 2021b release, there is some commentary about the release that isn't indented to the level of the "Briefly" sub-block, but also doesn't have its own heading. I think it would be preferable to put this note under a heading rather than as free-floating content at the level of other subheads. I've attached a patch to move the note into the "Briefly" subheading, though it could also be a separate heading like "Note about the 2021b release" or something. I don't really expect this format to be guaranteed or anything, but for selfish reasons I liked the consistency of the previous format since it makes it much easier for me to parse the NEWS file for repackaging in the Python tzdata format. Obviously I do not consider this any sort of contract or required interface, but since it seems unlikely that accepting this patch would increase your maintenance burden and it will decrease my maintenance burden by a decent amount in the future, I'm hoping you wont' mind accepting this patch (or a similar one). Thanks! Paul

2 1