time_t time(time_t *timer);

      struct tm *localtime(const time_t *timer);


      The  header file contains declarations of all relevant
      functions and externals.  It also contains the tm structure, which
      includes the following members:

           int tm_sec;      /* seconds after the minute - [0,61] */
           int tm_min;      /* minutes after the hour - [0,59] */
           int tm_hour;     /* hours - [0,23] */
           int tm_mday;     /* day of month - [1,31] */
           int tm_mon;      /* month of year - [0,11] */
           int tm_year;     /* years since 1900 */
           int tm_wday;     /* days since Sunday - [0,6] */
           int tm_yday;     /* days since January 1 - [0,365] */
           int tm_isdst;    /* daylight savings time flag */

           The value of tm_isdst is positive if a summer time zone
           adjustment such as Daylight Savings Time is in effect, zero if
           not in effect, and negative if the information is not available.