Web Standards Programmer's Reference: HTML, CSS, JavaScript®, Perl, Python®, and PHP

F.9. Date and Time

Function	Returns	Description
time(void)	int	Returns current UNIX timestamp.
mktime(int hour, int min, int sec, int mon, int day, int year)	int	Gets UNIX timestamp for a date.
gmmktime(int hour, int min, int sec, int mon, int day, int year)	int	Gets UNIX timestamp for a GMT date.
date(string format [, int timestamp])	string	Formats a local time/date.
gmdate(string format [, int timestamp])	string	Formats a GMT/UTC date/time.
idate(string format [, int timestamp])	int	Formats a local time/date as integer.
localtime([int timestamp [, bool associative_array]])	array	Returns the results of the C system call local time as an associative array if the associative_array argument is set to 1 (otherwise it's a regular array).
getdate([int timestamp])	array	Gets date/time information.
checkdate(int month, int day, int year)	bool	Returns true(1) if it is a valid date in Gregorian calendar.
strftime(string format [, int timestamp])	string	Formats a local time/date according to locale settings.
gmstrftime(string format [, int timestamp])	string	Formats a GMT/UTC time/date according to locale settings.
strtotime(string time, int now)	int	Converts string representation of date and time to a timestamp.
microtime(void)	string	Returns a string containing the current time in seconds and microseconds.
gettimeofday(void)	array	Returns the current time as array.
getrusage([int who])	array	Returns an array of usage statistics.
date_sunrise(mixed time [, int format [, float latitude [, float longitude ...