timelocal

TIMEGM(3)		  Linux Programmer’s Manual		    TIMEGM(3)



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 local-
       time(3) and gmtime(3).

NOTES
       These functions are  GNU	 extensions.   The  timelocal()	 function  is
       equivalent to the POSIX standard function mktime(3).  There is no rea-
       son 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(tm);
		  if (tz)
		      setenv("TZ", tz, 1);
		  else
		      unsetenv("TZ");
		  tzset();
		  return ret;
	      }

SEE ALSO
       gmtime(3), localtime(3), mktime(3), tzset(3)



GNU				  2001-12-26			    TIMEGM(3)