সি

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

int main() {
  time_t current = time(NULL);

  printf("%lld", (long long)current);

  return 0;
}

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

int main() {
  time_t current = time(NULL);
  struct tm *local = localtime(&current);

  printf("%d:%%d:%%d",
    local->tm_hour,
    local->tm_min,
    local->tm_sec
  );

  return 0;
}

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

int main() {
  time_t current = time(NULL);
  struct tm *utc = gmtime(&current);

  printf("%d:%%d:%%d",
    utc->tm_hour,
    utc->tm_min,
    utc->tm_sec
  );

  return 0;
}

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

int main() {
  struct tm date = {0};

  date.tm_year = 2026 - 1900;
  date.tm_mon = 8;
  date.tm_mday = 30;

  time_t current = mktime(&date);

  printf("%lld", (long long)current);

  return 0;
}

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

int main() {
  char text[50];
  time_t current = time(NULL);
  struct tm *local = localtime(&current);

  strftime(text, sizeof(text), "%%Y-%%m-%%d", local);

  printf("%s", text);

  return 0;
}

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

int main() {
  time_t current = time(NULL);
  struct tm *local = localtime(&current);

  printf("%s", asctime(local));

  return 0;
}

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

int main() {
  time_t current = time(NULL);

  printf("%s", ctime(&current));

  return 0;
}

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

int main() {
  time_t start = time(NULL);
  time_t end = start + 10;

  printf("%.0f", difftime(end, start));

  return 0;
}

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

int main() {
  clock_t start = clock();

  for (long i = 0; i < 1000000; i++) {
  }

  clock_t end = clock();

  printf("%f",
    (double)(end - start) / CLOCKS_PER_SEC
  );

  return 0;
}