Fwd: [IANA #1283803] Europe/Amsterdam
Please also see the forwarded message. ........................................................................................ We have some kind of a short discussion on a timezone. We are looking for the correct answer. *Is Europe/Amsterdam currently an IANA compliant timezone?* We see in the most recent version it is linked backwards to Europe/Brussels But does that means that Europe/Amsterdam is no longer compliant. Is zone.tab an actual representation of all current iana compliant timezones? We read a first comment line "tzdb timezone descriptions (deprecated version)" ---------- Forwarded message --------- From: David Dong via RT <iana-questions@iana.org> Date: Mon, Oct 16, 2023 at 6:18 PM Subject: [IANA #1283803] Europe/Amsterdam To: <leo.bekhuis@sqills.com> Hi Leo, Thank you for contacting us. We host the Time Zone Database, but updates are made by the Time Zone Coordinator in consultation with the Time Zone mailing list, in accordance with RFC 6557. You may wish to contact the mailing list, tz@iana.org, directly to inquire about Europe/Amsterdam. For mailing list information, please see: http://www.iana.org/time-zones Best regards, David Dong IANA Services Sr. Specialist On Fri Oct 13 09:26:53 2023, leo.bekhuis@sqills.com wrote:
Hi,
We have some kind of a short discussion on a timezone.
We are looking for the correct answer.
*Is Europe/Amsterdam currently an IANA compliant timezone?*
We see in the most recent version it is linked backwards to Europe/Brussels But does that means that Europe/Amsterdam is no longer compliant.
Is zone.tab an actual representation of all current iana compliant timezones? We read a first comment line "tzdb timezone descriptions (deprecated version)"
Thanks
Leo Bekhuis
P +31 887 745 570 [image: Sqills - exceeding expectations] <https://www.sqills.com> LinkedIn <https://www.linkedin.com/company/sqills> | Facebook <https://www.facebook.com/Sqills/> | Twitter <https://twitter.com/sqills> Sqills has been awarded the ISO 9001:2015, 27001:2017, ISAE 3402, and PCI DSS certification. We take pride in building secure and high quality software This e-mail message is intended exclusively for the addressee or addressees and may contain personal and/or confidential information. If you have received this message in error, please notify the sender and delete this message from your system immediately. We also request that you neither use the contents nor disclose them in any manner to third parties, because the message may contain information which is protected by professional secrecy.
-- Leo Bekhuis P +31 887 745 570 [image: Sqills - exceeding expectations] <https://www.sqills.com> LinkedIn <https://www.linkedin.com/company/sqills> | Facebook <https://www.facebook.com/Sqills/> | Twitter <https://twitter.com/sqills> Sqills has been awarded the ISO 9001:2015, 27001:2017, ISAE 3402, and PCI DSS certification. We take pride in building secure and high quality software This e-mail message is intended exclusively for the addressee or addressees and may contain personal and/or confidential information. If you have received this message in error, please notify the sender and delete this message from your system immediately. We also request that you neither use the contents nor disclose them in any manner to third parties, because the message may contain information which is protected by professional secrecy. -- This e-mail message is intended exclusively for the addressee or addressees and may contain personal and/or confidential information. If you have received this message in error, please notify the sender and delete this message from your system immediately. We also request that you neither use the contents nor disclose them in any manner to third parties, because the message may contain information which is protected by professional secrecy.
On 2023-10-17 05:08, Leo Bekhuis via tz wrote:
We have some kind of a short discussion on a timezone. We are looking for the correct answer. *Is Europe/Amsterdam currently an IANA compliant timezone?*
The IANA RFC specifies only management, maintenance, and release procedures for tzdb data, so as a whole it is compliant to that RFC. Individual zone data are discussed on the list, and decisions and changes are summarized in the comments for each zone and rule in each data file, and on the mailing list at (sometimes much) greater length.
We see in the most recent version it is linked backwards to Europe/Brussels
With some builds, intended to reduce the distributed size, all zones with the same time history agreeing since 1970, may be consolidated by ignoring history before 1970, and linking to a zone with a larger population centre and the same history.*
But does that means that Europe/Amsterdam is no longer compliant.
Compliant to what decree, law, regulation, or standard?
Is zone.tab an actual representation of all current iana compliant timezones?
That file or its consolidated alternative zone1970.tab may be used in a build to control the zones built.*
We read a first comment line "tzdb timezone descriptions (deprecated version)"
That is the current maintainer's view of the use of that file and related history. The development repository can provide the detailed history of each data file, zone, and rule since project inception in SCCS in 1986: https://github.com/eggert/tz although consolidation may have made it harder to find historical details. *It is up to each distro, packager, org, or developer, how they decide to tailor the features and size of the build of the utilities and data files they use: whether to include backward compatibility zones and links; and whether zones and rules use and generate values which are mainstream "standard" main, backwards compatible "rearguard", or require leading edge utilities and libraries to handle "vanguard"; whether they include POSIXRULES, leap seconds and TAI offset "right" data files, various time_t types, etc. -- Take care. Thanks, Brian Inglis Calgary, Alberta, Canada La perfection est atteinte Perfection is achieved non pas lorsqu'il n'y a plus rien à ajouter not when there is no more to add mais lorsqu'il n'y a plus rien à retirer but when there is no more to cut -- Antoine de Saint-Exupéry
On 10/17/23 04:08, Leo Bekhuis via tz wrote:
*Is Europe/Amsterdam currently an IANA compliant timezone?*
"An IANA compliant timezone" is not a well-defined concept. As <https://data.iana.org/time-zones/tz-link.html> says, the tz code and data are by no means authoritative. (Brian discussed this in more detail in his reply.) Possibly you are asking about timestamps before the year 1970? Although TZDB's scope is timestamps since 1970, because of its formats it also covers pre-1970 timestamps in limited ways. In the latest TZDB release (2023c) with the default settings, Europe/Amsterdam is a Link to Europe/Brussels so their timestamps are identical. However, if you use some non-default options when building from 2023c, Europe/Amsterdam becomes a separate Zone with data that differ from Europe/Brussels for some pre-1970 timestamps; although this optional Zone is also incorrect for some pre-1970 timestamps, it's closer to being right. The non-default options exist for compatibility with older verions of TZDB that were more ambitious (arguably too ambitious) in their attempt to cover pre-1970 timestamps. One other thing: downstream distributions commonly tailor TZDB for their own needs. Often there's no combination of options for the IANA-distributed TZDB that will generate timestamps that exactly match what you observe on your own system. So one must be careful about phrases like "IANA compliant timezone". If you want 100% reproducible timestamps, you'll need to give more detail about how you derived the timestamps.
participants (3)
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Brian Inglis -
Leo Bekhuis -
Paul Eggert