#include <stdio.h>

#define _XOPEN_SOURCE
#include <time.h>

time_t strtotime (const char *s_time);

int main ()
{
	struct tm	*ts_gmt;
	time_t		 time_post;
	time_t		 time_gmt;
	time_t		 time_local = time(NULL);

	/* Get post timestamp */
	time_post = strtotime ("Sat Oct 06 19:52:04 +0000 2007");

	/* Get GMT time */
	ts_gmt = gmtime ( &time_local );
	time_gmt = mktime (ts_gmt);

	printf ("POST: %d\n GMT: %d\n Diff: %d\n",
		time_post,
		time_gmt,
		time_gmt-time_post);

	return 0;
}

time_t
strtotime (const char *s_time)
{
	struct tm time;

	strptime (s_time, "%a %b %d %T +0000 %Y", &time);

	return mktime(&time);
}