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Re: Question about reproducibility tests timezone format



Soren Stoutner <soren@debian.org> writes:

> Can you think of any way that using the Etc/GMT+12 and Etc/GMT-14 syntax
> would cause any *problems*?

Yes: Etc/GMT+12 and Etc/GMT-14 generate different time zone abbreviations.

% env TZ=Etc/GMT+12 date
Thu Oct  2 05:31:10 AM -12 2025
% env TZ=Etc/GMT-14 date
Fri Oct  3 07:31:14 AM +14 2025

The point of using GMT+12 and GMT-12 is that they keep the same
(incorrect, but it doesn't really matter for this purpose) time zone
abbreviation for reproducibility testing:

% env TZ=GMT+12 date
Thu Oct  2 05:32:09 AM GMT 2025
% env TZ=GMT-12 date
Fri Oct  3 05:32:12 AM GMT 2025

Otherwise, you may get spurious reproducibility failures due to the
changed time zone abbreviation.

I don't believe there is a mechanism to force the same time zone
abbreviation other than usig POSIX rule-based zones.

-- 
Russ Allbery (rra@debian.org)              <https://www.eyrie.org/~eagle/>


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