#include <time.h>
char *asctime (struct tm *time) - Convert time from struct tmto string.
clock_t clock(void) - Get elapsed processor time in clock ticks.
char *ctime(time_t *time) - Convert binary time to string. double difftime(time_t time2, time_t time1) - Compute the difference between two times in seconds.
st ruct_tm *gmtime (time_t *time) - Get Greenwich Mean Time (GMT) in a tm structure.
struct tm *localtime(time_t *time) - Get the local time in a tm structure.
time_t time(time_t *timeptr) - Get current times as seconds elapsed since 0 hours GMT 1/1/70.