<time.h>

The <time.h> include file declares the time and date functions:


`asctime` `asctime_r` `clock` `ctime` `ctime64`	`ctime_r` `ctime64_r` `difftime` `difftime64` `gmtime`	`gmtime64` `gmtime_r` `gmtime64_r` `localtime` `localtime64`	`localtime_r` `localtime64_r` `mktime` `mktime64` `strftime`	`strptime`¹ `time` `time64`
Note: ¹ These functions are not available when LOCALETYPE(*CLD) is specified on the compilation command.

The <time.h> include file also provides:

A structure tm that contains the components of a calendar time. See gmtime() — Convert Time for a list of the tm structure members.
A macro CLOCKS_PER_SEC equal to the number per second of the value that is returned by the clock function.
Types clock_t, time_t, time64_t, and size_t.
The NULL pointer value.

For more information about NULL and the type size_t, see <stddef.h>.