The time.h file exists. The time.h header declares struct tm with the members below, at a minimum: tm_sec tm_min tm_hour tm_mday tm_mon tm_year tm_wday tm_yday tm_isdst The time.h header defines the symbolic names below: NULL CLOCKS_PER_SEC CLOCK_PROCESS_CPUTIME_ID (TMR,CPT) CLOCK_THREAD_CPUTIME_ID (TMR,TCT) The time.h header declares struct timespec with the members below, at a minimum: time_t tv_sec long tv_nsec The time.h header declares struct itimerspec with the members below, at a minimum: struct timespec it_interval struct timespec it_value The manifest constants below are defined: CLOCK_REALTIME TIMER_ABSTIME CLOCK_MONOTONIC (@pt:MON) sys/types.h shall define clock_t, size_t, time_t, clockid_t (@pt:TMR), and timer_t (@pt:TMR). The function below is defined: char *asctime(const struct tm *); The function below is defined: char *asctime_r(const struct tm *restrict, char *restrict); The function below is defined: clock_t clock(void); The function below is defined: int clock_getcpuclockid(pid_t, clockid_t *); The function below is defined: int clock_getres(clockid_t, struct timespec *); The function below is defined: int clock_gettime(clockid_t, struct timespec *); The function below is defined: int clock_nanosleep(clockid_t, int, const struct timespec *, struct timespec *); The function below is defined: int clock_settime(clockid_t, const struct timespec *); The function below is defined: char *ctime(const time_t *); The function below is defined: char *ctime_r(const time_t *, char *); The function below is defined: double difftime(time_t, time_t); The function below is defined: struct tm *getdate(const char *); The function below is defined: struct tm *gmtime(const time_t *); The function below is defined: struct tm *gmtime_r(const time_t *restrict, struct tm *restrict); The function below is defined: struct tm *localtime(const time_t *); The function below is defined: struct tm *localtime_r(const time_t *restrict, struct tm *restrict); The function below is defined: time_t mktime(struct tm *); The function below is defined: int nanosleep(const struct timespec *, struct timespec *); The function below is defined: size_t strftime(char *restrict, size_t, const char *restrict, const struct tm *restrict); The function below is defined: char *strptime(const char *restrict, const char *restrict, struct tm *restrict); The function below is defined: time_t time(time_t *); The function below is defined: int timer_create(clockid_t, struct sigevent *restrict, timer_t *restrict); The function below is defined: int timer_delete(timer_t); The function below is defined: int timer_gettime(timer_t, struct itimerspec *); The function below is defined: int timer_getoverrun(timer_t); The function below is defined: int timer_settime(timer_t, int, const struct itimerspec *restrict, struct itimerspec *restrict); The function below is defined: void tzset(void); The variables below are declared: extern int daylight; (@pt:XSI) extern long timezone; extern char *tzname[]; (@pt:CX)