Sept. 4, 2021
8:36 a.m.
On Sep 3, 2021, at 6:11 PM, Paul Eggert <eggert@cs.ucla.edu> wrote:
A and B might have different values if tzdb is updated between the two calls to localtime_rz. Even though tz is a time zone "value", it is a "value" that mutates when tzdb is updated. This usage appears to be particularly problematic, as part of the point of localtime_rz is speed and thread-safety, and I'd hate for it to have to consult the filesystem.
As far as I know, the Darwin scheme does not bother checking for tzdb updates, it just handles explicit notifications that the system time zone has changed, so this would be a change over and above what you get in, for example, macOS.