On 2024-05-02 12:35, Paul Eggert via tz wrote:
On 2024-04-30 16:21, Arthur David Olson via tz wrote:
For a given zone, each line describing the zone except for the last ends with an until time. The creation of the transition time entry for the until time is deferred until the following zone line has been completely processed. (It happens at the bottom of the giant for loop in outzone.) That deferral means that the time zone abbreviations in use have been computed, so the appropriate abbreviation can be applied to the until time.
OK, but this wouldn't address the issue of what happens with the last zone line, as that lacks an until time. For example:
Rule Aus 1917 only - Jan 1 2:00 1:00 D Rule Aus 1917 only - Mar 1 2:00 0 S Zone Australia/Sydney 10:00 Aus AE%sT
zic generates a TZif file where time type 0 (the time type before 1917) uses the abbreviation "AEST" - but where did that "S" come from? The documentation doesn't say. I think this is Jonathan's main point.
When computing %s for timestamps that come before the earliest rule, zic uses the LETTER/S field of the earliest rule that specifies standard time. I installed the attached to try to document this.
I would expect it to default to "S" to allow "%s" in zones without rules. -- 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