1@node tzset
2@section @code{tzset}
3@findex tzset
4
5POSIX specification:@* @url{https://pubs.opengroup.org/onlinepubs/9699919799/functions/tzset.html}
6
7Gnulib module: tzset
8
9Portability problems fixed by Gnulib:
10@itemize
11@item
12On native Windows platforms (mingw, MSVC), this function works incorrectly
13when the environment variable @code{TZ} has been set by Cygwin.
14@end itemize
15
16Portability problems not fixed by Gnulib:
17@itemize
18@item
19Native Windows platforms (mingw, MSVC) support only a subset of
20POSIX-specified values for the @env{TZ} environment variable,
21consisting of a time zone abbreviation containing exactly three ASCII
22letters with no daylight saving time or angle brackets, and with no
23support for @code{tz} database settings like
24@code{TZ='America/New_York'}.  Even this subset does not work on
25applications built via the Universal Windows Platform, as it does not
26make environment variables like @env{TZ} available to applications.
27@item
28Older POSIX platforms do not support angle brackets in @env{TZ} values,
29as this feature was added in IEEE Std 1003.1-2001.
30@end itemize
31