#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <time.h>
#include <sys/time.h>

 

int main(int argc, char *argv[])
{
 time_t mytime = time(0);
 struct tm* tm_ptr = localtime(&mytime);
 if (tm_ptr)
 {
  tm_ptr->tm_mon  = 5;
  tm_ptr->tm_mday = 1;

  const struct timeval tv = {mktime(tm_ptr), 0};
  settimeofday(&tv, 0);
  }

 return 0;
}