@node localtime
@subsection @code{localtime}
@findex localtime

POSIX specification:@* @url{https://pubs.opengroup.org/onlinepubs/9799919799/functions/localtime.html}

Gnulib module: localtime
@mindex localtime

Portability problems fixed by Gnulib:
@itemize
@item
On native Windows platforms (mingw, MSVC), this function works incorrectly
when the environment variable @env{TZ} has been set by Cygwin.
@end itemize

Portability problems not fixed by Gnulib:
@itemize
@item
On some platforms, this function loops forever for values
near extrema (such as the year @math{-2**31}):
Mac OS X 10.6.
@mindex time_rz
You can use the @code{time_rz} module to work around the problem.
@item
On some platforms, this function returns nonsense values for
unsupported arguments (like @math{2^56}), rather than failing:
FreeBSD 10.
@item
On some platforms, this function yields incorrect values for
timestamps before the year 1:
MacOS X 10.5, Solaris 11.3.
@item
On some platforms, this function returns NULL for negative arguments, that is,
for timestamps before 1970-01-01 00:00:00 local time:
mingw, MSVC.
@item
Native Windows platforms (mingw, MSVC) support only a subset of time
zones supported by GNU or specified by POSIX@.  @xref{tzset}.
@end itemize
