time.h Types and Macros

clock_t

Stores processor time values.

Prototype

typedef long clock_t

struct tm

Structure used to hold the time and date (calendar time).

Prototype

struct tm {
int tm_sec;       /*seconds after the minute ( 0 to 61 )*/
                  /*allows for up to two leap seconds*/
int tm_min;       /*minutes after the hour ( 0 to 59 )*/
int tm_hour;      /*hours since midnight ( 0 to 23 )*/
int tm_mday;      /*day of month ( 1 to 31 )*/
int tm_mon;       /*month ( 0 to 11 where January = 0 )*/
int tm_year;      /*years since 1900*/
int tm_wday;      /*day of week ( 0 to 6 where Sunday = 0 )*/
int tm_yday;      /*day of year ( 0 to 365 where January 1 = 0 )*/
int tm_isdst;     /*Daylight Savings Time flag*/
}

Remarks

If tm_isdst is a positive value, Daylight Savings is in effect. If it is zero, Daylight Saving Time is not in effect. If it is a negative value, the status of Daylight Saving Time is not known.

time_t

Represents calendar time values.

Prototype

typedef long time_t

The following macro is included in time.h

CLOCKS_PER_SEC

Number of processor clocks per second.

Prototype

#define CLOCKS_PER_SEC

Value

1

Remarks

The compiler returns clock ticks (instruction cycles) not actual time.