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

int main(int argc, char *argv[])
{
    time_t t;
    struct tm tm = {0};
    char buf[64];

    if (argc < 7) {
        fprintf(stderr, "Usage: %s year month day hour minute second\n");
        return EXIT_FAILURE;
    }

    tm.tm_year = atoi(argv[1]) - 1900;
    tm.tm_mon = atoi(argv[2]) - 1;
    tm.tm_mday = atoi(argv[3]);
    tm.tm_hour = atoi(argv[4]);
    tm.tm_min = atoi(argv[5]);
    tm.tm_sec = atoi(argv[6]);

    mktime(&tm);
    strftime(buf, sizeof buf, "%F %T %Z", &tm);
    printf("before: %s\n", buf);
    tm.tm_min += 2;
    mktime(&tm);
    strftime(buf, sizeof buf, "%F %T %Z", &tm);
    printf("after: %s\n", buf);
    return 0;
}