Re:RFC 3339 vs. ISO 8601
by lmm on Sunday September 07, 2025 @07:30AM
(#45157274)
Specifying an offset, as certain datetime formats do, is worse than not specifying any timezone information at all. I'm not aware of a standardised computer date format that includes the symbolic timezone, sadly.
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Agreed, offsets are an anti-pattern. Any time you have a nonzero offset you almost certainly want either a tz name (e.g. Europe/Paris), a local datetime, an instant, or a formatted string.
Re:RFC 3339 vs. ISO 8601
by burntsushi on Sunday September 07, 2025 @09:10AM
(#45157879)
> Datetime + tz name: a point in time and space that is responsive to time zone changes
No. It isn't a point in time, because time zone transition rules can and do change. You need an offset as well. Then you can choose which thing you want to prioritize[1] when converting it to an instant in time.
This is what RFC 9557 is for.
[1]: https://docs.rs/jiff/latest/jiff/tz/enum.OffsetConflict.html