dev/c/time_t_2038/gmtime.c

#define _XOPEN_SOURCE

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

int main(int argc, char *argv[])
{
	struct tm t, *tp = NULL;
	time_t tt;
	char outstr[200];

	putenv("TZ=Europe/Moscow");

	t.tm_sec = 1;
	t.tm_min = 2;
	t.tm_hour = 3;
	t.tm_mday = 4;
	t.tm_mon = 5;
	t.tm_year = 1000;
	t.tm_isdst = 0;
	
	tt = mktime(&t);

	tp = gmtime(&tt);

	if (strftime(outstr, sizeof(outstr), "%Y.%m.%d", tp) != 0)
		printf("%s\n", outstr);

	printf("%d\n", sizeof(time_t));

	printf("%lu\n", tt);

	printf("%d\n", sizeof(struct tm));

	printf("%s\n", asctime(tp));
	
	return 0;
}