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.