Hi Michael, Current strftime specification in C language standard is not accurate. It tells that tm_isdst is enough to find out time zone's offset. But that's not true, for example Europe/Lisbon has changed [0] its standard offset from 00:00 to 01:00 and back to 00:00, so an exact date is needed to answer that. To get correct answer with the current glibc tm struct should either come from localtime or there should be a mktime call prior to strftime. You can find a repro example and discussion here [1]. Paul Eggert has proposed a fix to C standard [2]. Should man pages reflect that i.e. mention that there should be localtime/mktime calls for %z and %Z? Thanks, Almaz P.S. I am resending the email. My previous attempt was bounced back as it wasn't TEXT/PLAIN. [0] https://github.com/eggert/tz/blob/a249a0c64b2f87a24c7f1aab43056fb597c95b96/europe#L2400 [1] https://mm.icann.org/pipermail/tz/2022-July/031668.html [2] https://mm.icann.org/pipermail/tz/2022-July/031674.html
