5 POSIX specification:@* @url{https://pubs.opengroup.org/onlinepubs/9699919799/functions/tzset.html}
9 Portability problems fixed by Gnulib:
12 On native Windows platforms (mingw, MSVC), this function works incorrectly
13 when the environment variable @code{TZ} has been set by Cygwin.
16 Portability problems not fixed by Gnulib:
19 Native Windows platforms (mingw, MSVC) support only a subset of
20 POSIX-specified values for the @env{TZ} environment variable,
21 consisting of a time zone abbreviation containing exactly three ASCII
22 letters with no daylight saving time or angle brackets, and with no
23 support for @code{tz} database settings like
24 @code{TZ='America/New_York'}. Even this subset does not work on
25 applications built via the Universal Windows Platform, as it does not
26 make environment variables like @env{TZ} available to applications.
28 Older POSIX platforms do not support angle brackets in @env{TZ} values,
29 as this feature was added in IEEE Std 1003.1-2001.