[tz] Tzdb and the Sunshine Protection Act

Paul Eggert eggert at cs.ucla.edu
Thu Mar 2 23:49:09 UTC 2023

On 3/2/23 15:32, Paul Gilmartin via tz wrote:
> The forms containing numbers are mandated by POSIX:

POSIX does not specify TZ strings like TZ='EST5EDT'; they are TZDB 
extensions. If you want a TZ string whose meaning is specified, you need 
something like TZ='EST5EDT,M3.2.0,M11.1.0'.

You can see this by looking a few lines before the lines you quoted, 
which say that a TZ string contents are "std offset dst offset, rule". 
Admittedly this part of POSIX could be written more clearly.

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