time.h

This header files defines types and constants for time management. See the following listing.

typedef 
clock_t;
typedef 
time_t;

struct tm {

  int tm_sec;     /* Seconds */

  int tm_min;     /* Minutes */

  int tm_hour;    /* Hours */

  int tm_mday;    /* Day of month: 0 .. 31 */

  int tm_mon;     /* Month: 0 .. 11 */

  int tm_year;    /* Year since 1900 */

  int tm_wday;    /* Day of week: 0 .. 6 (Sunday == 0) */

  int tm_yday;    /* day of year: 0 .. 365 */

  int tm_isdst;   /* Daylight saving time flag:

                     > 0  It is DST

                       0  It is not DST

                     < 0  unknown */

};

The constant CLOCKS_PER_SEC gives the number of clock ticks per second.