Example

 /* Exercise the wcsftime formatting routine.             */
 /* NOTE: the format string is an "L" (or wide character) */
 /*       string indicating that this call is NOT in      */
 /*       the XPG4 format, but rather in ISO C format.    */

#include <stdlib.h>
#include <stdio.h>
#include <time.h>
#include <wchar.h>
#include <locale.h>
#include <errno.h>

#define NUM_OF_DATES  7
#define BUF_SIZE 256

 /* This program formats a number of different dates, once using the   */
 /* C locale and then using the fr_FR.ISO8859-1 locale.  Date and time */
 /* formatting is done using wcsftime().                               */

main()

{
  int count,
      i;
  wchar_t buffer[BUF_SIZE];
  struct tm *tm_ptr;
  time_t time_list[NUM_OF_DATES] =
  {500, 68200000, 694223999,
   694224000, 704900000, 705000000,
   705900000};

  /* Display dates using the C locale */
  printf("\nUsing the C locale:\n\n");

  setlocale(LC_ALL, "C");

  for (i = 0; i < NUM_OF_DATES; i++) {
      /* Convert to a tm structure */
      tm_ptr = localtime(&time_list[i]);

      /* Format the date and time */
      count = wcsftime(buffer, BUF_
SIZE, L"Date: %A %d %B %Y%nTime: %T%n%n",
                      tm_ptr);
      if (count == 0) {
          perror("wcsftime");
          exit(EXIT_FAILURE);
      }

      /* Print the result */
      printf("%S", buffer);
  }

  /* Display dates using the fr_FR.ISO8859-1 locale */
  printf("\nUsing the fr_FR.ISO8859-1 locale:\n\n");

  setlocale(LC_ALL, "fr_FR.ISO8859-1");

  for (i = 0; i < NUM_OF_DATES; i++) {
      /* Convert to a tm structure */
      tm_ptr = localtime(&time_list[i]);

      /* Format the date and time */
      count = wcsftime(buffer, BUF_
SIZE, L"Date: %A %d %B %Y%nTime: %T%n%n",
                       tm_ptr);
      if (count == 0) {
          perror("wcsftime");
          exit(EXIT_FAILURE);
      }

      /* Print the result */
      printf("%S", buffer);
  }
}

   Running the example program produces the following result:

   Using the C locale:

   Date: Thursday 01 January 1970
   Time: 00:08:20

   Date: Tuesday 29 February 1972
   Time: 08:26:40

   Date: Tuesday 31 December 1991
   Time: 23:59:59

   Date: Wednesday 01 January 1992
   Time: 00:00:00

   Date: Sunday 03 May 1992
   Time: 13:33:20

   Date: Monday 04 May 1992
   Time: 17:20:00

   Date: Friday 15 May 1992
   Time: 03:20:00

   Using the fr_FR.ISO8859-1 locale:

   Date: jeudi 01 janvier 1970
   Time: 00:08:20

   Date: mardi 29 février 1972
   Time: 08:26:40

   Date: mardi 31 décembre 1991
   Time: 23:59:59

   Date: mercredi 01 janvier 1992
   Time: 00:00:00

   Date: dimanche 03 mai 1992
   Time: 13:33:20

   Date: lundi 04 mai 1992
   Time: 17:20:00

   Date: vendredi 15 mai 1992
   Time: 03:20:00