/* Copyright (C) 1999, 2001-2002 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Library General Public License as
   published by the Free Software Foundation; either version 2 of the
   License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Library General Public License for more details.

   You should have received a copy of the GNU Library General Public
   License along with the GNU C Library; see the file COPYING.LIB.  If not,
   <http://www.gnu.org/licenses/>.
*/

#ifdef HAVE_CONFIG_H
# include "config.h"
#endif

#include "egg-timegm.h"

#ifndef HAVE_TIMEGM

time_t
timegm(struct tm *t)
{
	time_t tl, tb;
	struct tm *tg;

	tl = mktime (t);
	if (tl == -1)
	{
		t->tm_hour--;
		tl = mktime (t);
		if (tl == -1)
			return -1;
		tl += 3600;
	    }
	tg = gmtime (&tl);
	tg->tm_isdst = 0;
	tb = mktime (tg);
	if (tb == -1)
	{
		tg->tm_hour--;
		tb = mktime (tg);
		if (tb == -1)
			return -1;
		tb += 3600;
	}
	return (tl - (tb - tl));
}

#endif