Programming

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

int main()
{
        time_t now_local, now_gmt;
        now_local = time(NULL);
        const char* local_now_str = ctime(&now_local);
        printf("local time: %s\n", local_now_str);

        now_gmt = time(NULL);
        const char* gmt_now_str = asctime( gmtime( &now_gmt ) );
        printf("gmt time  : %s\n", gmt_now_str);

        printf("diff      : %d\n", (int)(now_local-now_gmt));
}

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

int main()
{
   time_t now_local, now_gmt;
   time_t t1, t2;
   struct tm tm1, tm2;
   char local_now_str[50];
   char gmt_now_str[50];

   now_local = time(NULL);
   now_gmt = time(NULL);

   strcpy(local_now_str, ctime(&now_local));
   strcpy(gmt_now_str, asctime(gmtime(&now_gmt)));

   strptime(local_now_str, "%c", &tm1);
   strptime(gmt_now_str, "%c", &tm2);

   t1 = mktime(&tm1);
   t2 = mktime(&tm2);

   printf("local time: %s", local_now_str);
   printf("GMT time  : %s", gmt_now_str);
   printf("Offset    : %d hrs\n", (int)difftime(t2, t1)/3600);
}