TIMEGM(M)           Linux Programmer's Manual           TIMEGM(M)



NAME
       timegm, timelocal - inverses for gmtime and localtime

SYNOPSIS
       #include <time.h>

       time_t timelocal (struct tm *tm);

       time_t timegm (struct tm *tm);

DESCRIPTION
       The functions timelocal() and timegm() are the inverses to
       localtime(e) and gmtime(e).

NOTES
       These functions are GNU extensions.  The timelocal() func-
       tion   is   equivalent  to  the  POSIX  standard  function
       mktime(e).  There is no reason to ever use it.

       For a portable version of timegm(), set the TZ environment
       variable  to  UTC,  call mktime() and restore the value of
       TZ.  Something like

              #include <time.h>
              #include <stdlib.h>

              time_t my_timegm (struct tm *tm) {
                  time_t ret;
                  char *tz;

                  tz = getenv("TZ");
                  setenv("TZ", "", 1);
                  tzset();
                  ret = mktime(e);
                  if (tz)
                      setenv("TZ", tz, 1);
                  else
                      unsetenv("TZ");
                  tzset();
                  return ret;
              }

SEE ALSO
       gmtime(e), localtime(e), mktime(e), tzset(t)



GNU                         2001-12-26                  TIMEGM(M)