#include <time.h>

time.h

includes: _time.h, _types.h, sys/cdefs.h, _bounds.h, Availability.h, sys/_types/_clock_t.h, sys/_types/_null.h, sys/_types/_size_t.h, sys/_types/_time_t.h, sys/_types/_timespec.h, _time.h, _time.h, _time.h

27 functions · 10 macros · 4 variables · 1 struct · 1 enum · 1 typedef

structtm

size 56, align 8

int	tm_sec	seconds after the minute [0-60]
int	tm_min	minutes after the hour [0-59]
int	tm_hour	hours since midnight [0-23]
int	tm_mday	day of the month [1-31]
int	tm_mon	months since January [0-11]
int	tm_year	years since 1900
int	tm_wday	days since Sunday [0-6]
int	tm_yday	days since January 1 [0-365]
int	tm_isdst	Daylight Savings Time flag
long	tm_gmtoff	offset from UTC in seconds
char *	tm_zone	timezone abbreviation

macroCLOCKS_PER_SEC

#define CLOCKS_PER_SEC ((clock_t)1000000)

[XSI]

variabletzname

extern char *_LIBC_CSTR tzname[_LIBC_COUNT(2)]

variablegetdate_err

extern int getdate_err

variabletimezone

extern long timezone

variabledaylight

extern int daylight

functionasctime

char *_LIBC_CSTR asctime(const struct tm *)

man page · January 2, 1999

asctime(3) — transform binary date and time values

functionclock

__DARWIN_ALIAS(clock)
clock_t clock(void)

man page · June 4, 1993

clock(3) — determine processor time used

functionctime

char *_LIBC_CSTR ctime(const time_t *)

man page · January 2, 1999

ctime(3) — transform binary date and time values

functiondifftime

double difftime(time_t, time_t)

man page · January 2, 1999

difftime(3) — transform binary date and time values

functiongetdate

struct tm *getdate(const char *)

man page · January 3, 2004

getdate(3) — convert user format date and time

functiongmtime

struct tm *gmtime(const time_t *)

man page · January 2, 1999

gmtime(3) — transform binary date and time values

functionlocaltime

struct tm *localtime(const time_t *)

man page · January 2, 1999

localtime(3) — transform binary date and time values

functionmktime

__DARWIN_ALIAS(mktime)
time_t mktime(struct tm *)

man page · January 2, 1999

mktime(3) — transform binary date and time values

functionstrftime

__DARWIN_ALIAS(strftime)
size_t strftime(
	char *_LIBC_COUNT(__maxsize) __restrict,
	size_t __maxsize,
	const char * __restrict,
	const struct tm * __restrict
)

man page · November 4, 2004

strftime(3) — format date and time

functionstrptime

__DARWIN_ALIAS(strptime)
char *_LIBC_CSTR strptime(
	const char * __restrict,
	const char * __restrict,
	struct tm * __restrict
)

man page · October 2, 2014

strptime(3) — parse date and time string

functiontime

time_t time(time_t *)

man page · July 18, 2003

time(3) — get time of day

functiontzset

void tzset(void)

man page · November 17, 1993

tzset(3) — initialize time conversion information

functionasctime_r

char *_LIBC_CSTR asctime_r(
	const struct tm * __restrict,
	char * __restrict _LIBC_COUNT(26)
)

[TSF] Thread safe functions

man page · January 2, 1999

asctime_r(3) — transform binary date and time values

functionctime_r

char *_LIBC_CSTR ctime_r(const time_t *, char *_LIBC_COUNT(26))

man page · January 2, 1999

ctime_r(3) — transform binary date and time values

functiongmtime_r

struct tm *gmtime_r(const time_t * __restrict, struct tm * __restrict)

man page · January 2, 1999

gmtime_r(3) — transform binary date and time values

functionlocaltime_r

struct tm *localtime_r(const time_t * __restrict, struct tm * __restrict)

man page · January 2, 1999

localtime_r(3) — transform binary date and time values

functionposix2time

time_t posix2time(time_t)

man page · September 11, 2005

posix2time(3) — convert seconds since the Epoch

functiontzsetwall

void tzsetwall(void)

man page · November 17, 1993

tzsetwall(3) — initialize time conversion information

functiontime2posix

time_t time2posix(time_t)

man page · September 11, 2005

time2posix(3) — convert seconds since the Epoch

functiontimelocal

time_t timelocal(struct tm * const)

man page · January 2, 1999

timelocal(3) — transform binary date and time values

functiontimegm

time_t timegm(struct tm * const)

man page · January 2, 1999

timegm(3) — transform binary date and time values

functionnanosleep

__DARWIN_ALIAS_C(nanosleep)
int nanosleep(const struct timespec *__rqtp, struct timespec *__rmtp)

man page · April 17, 1997

nanosleep(2) — suspend thread execution for an interval measured in nanoseconds

enumclockid_t

underlying type unsigned int

_CLOCK_REALTIME	0
_CLOCK_MONOTONIC	6
_CLOCK_MONOTONIC_RAW	4
_CLOCK_MONOTONIC_RAW_APPROX	5
_CLOCK_UPTIME_RAW	8
_CLOCK_UPTIME_RAW_APPROX	9
_CLOCK_PROCESS_CPUTIME_ID	12
_CLOCK_THREAD_CPUTIME_ID	16

typedefclockid_t

typedef enum clockid_t clockid_t;

macroCLOCK_REALTIME

#define CLOCK_REALTIME _CLOCK_REALTIME

macroCLOCK_MONOTONIC

#define CLOCK_MONOTONIC _CLOCK_MONOTONIC

macroCLOCK_MONOTONIC_RAW

#define CLOCK_MONOTONIC_RAW _CLOCK_MONOTONIC_RAW

macroCLOCK_MONOTONIC_RAW_APPROX

#define CLOCK_MONOTONIC_RAW_APPROX _CLOCK_MONOTONIC_RAW_APPROX

macroCLOCK_UPTIME_RAW

#define CLOCK_UPTIME_RAW _CLOCK_UPTIME_RAW

macroCLOCK_UPTIME_RAW_APPROX

#define CLOCK_UPTIME_RAW_APPROX _CLOCK_UPTIME_RAW_APPROX

macroCLOCK_PROCESS_CPUTIME_ID

#define CLOCK_PROCESS_CPUTIME_ID _CLOCK_PROCESS_CPUTIME_ID

macroCLOCK_THREAD_CPUTIME_ID

#define CLOCK_THREAD_CPUTIME_ID _CLOCK_THREAD_CPUTIME_ID

functionclock_getres

__CLOCK_AVAILABILITY
int clock_getres(clockid_t __clock_id, struct timespec *__res)

man page · January 26, 2016

clock_getres(3) — get/set date and time

functionclock_gettime

__CLOCK_AVAILABILITY
int clock_gettime(clockid_t __clock_id, struct timespec *__tp)

man page · January 26, 2016

clock_gettime(3) — get/set date and time

functionclock_gettime_nsec_np

__CLOCK_AVAILABILITY
__uint64_t clock_gettime_nsec_np(clockid_t __clock_id)

man page · January 26, 2016

clock_gettime_nsec_np(3) — get/set date and time

functionclock_settime

__OSX_AVAILABLE(10.12) __IOS_PROHIBITED __TVOS_PROHIBITED __WATCHOS_PROHIBITED
int clock_settime(clockid_t __clock_id, const struct timespec *__tp)

man page · January 26, 2016

clock_settime(3) — get/set date and time

macroTIME_UTC

ISO/IEC 9899:201x 7.27.2.5 The timespec_get function

#define TIME_UTC 1

time elapsed since epoch

functiontimespec_get

__API_AVAILABLE(macosx(10.15), ios(13.0), tvos(13.0), watchos(6.0))
int timespec_get(struct timespec *ts, int base)

man page · August 26, 2018

timespec_get(3) — get current calendar time