Introduction to PHP Date/Time

The Date/Time function allows you to get the date and time from the server where the PHP script is running. You can use the Date/Time functions to format dates and times in different ways.

Notes: These functions rely on the local settings of the server. Remember to take daylight saving time and leap years into account when using these functions.

Installation

PHP Date/Time functions are part of the core of PHP. No installation is required to use these functions.

Runtime Configuration

The behavior of the Date/Time function is affected by the settings in php.ini:

Name	Description	Default	PHP version
date.timezone	Specifies the default time zone (all Date/Time function uses this option)	""	PHP 5.1
date.default_latitude	Specifies the default latitude (date_sunrise() and date_sunset() uses this option)	"31.7667"	PHP 5.0
date.default_longitude	Specifies the default longitude (date_sunrise () and date_sunset() use this option)	"35.2333"	PHP 5.0
date.sunrise_zenith	Specifies the default Sunrise zenith (date_sunrise() and date_sunset() use this option)	"90.83"	PHP 5.0
date.sunset_zenith	Specifies the default sunset zenith (date_sunrise() and date_sunset() use this option)	"90.83"	PHP 5.0

PHP 5 Date/Time Function

Function	Description
checkdate()	Verify Gregorian date.
date_add()	Add day, month, year, hour, minute and second to a date.
date_create_from_format()	Returns a new DateTime object formatted according to the specified format.
date_create()	Returns a new DateTime object.
date_date_set()	Set a new date.
date_default_timezone_get()	Returns the default time zone, used by all Date/Time functions.
date_default_timezone_set()	Set the default time zone, used by all Date/Time functions.
date_diff()	Returns the difference between two dates.
date_format()	Returns the date formatted according to the specified format.
date_get_last_errors()	Returns warnings/errors in the date string.
date_interval_create_from_date_string()	Creates a DateInterval from the relevant part of the string.
date_interval_format()	Format time interval.
date_isodate_set()	Set ISO date.
date_modify()	Modify the timestamp.
date_offset_get()	Returns the time zone offset.
date_parse_from_format()	Returns an associative array with details of the specified date according to the specified format.
date_parse()	Returns an associative array with details for the specified date.
date_sub()	Subtract the day, month, year, hours, minutes, and seconds from the specified date.
date_sun_info()	Returns an array containing information about sunrise/sunset and dusk start/dusk end for the specified date and location.
date_sunrise()	Returns the sunrise time of the specified date and location.
date_sunset()	Returns the sunset time of the specified date and location.
date_time_set()	Set the time.
date_timestamp_get()	Returns the Unix timestamp.
date_timestamp_set()	Sets the date and time based on a Unix timestamp.
date_timezone_get()	Returns the time zone of the given DateTime object.
date_timezone_set()	Set the time zone of the DateTime object.
date()	Format local date and time.
getdate()	Returns the date/time information of a timestamp or the current local date/time.
gettimeofday()	Returns the current time.
gmdate()	Format GMT/UTC date and time.
gmmktime()	Returns the UNIX timestamp of the GMT date.
gmstrftime()	Format GMT/UTC date and time according to locale settings.
idate()	Format local time/date as an integer.
localtime()	Returns the local time.
microtime()	Returns the number of microseconds in the current Unix timestamp.
mktime()	Returns the Unix timestamp of a date.
strftime()	Format local time/date according to locale settings.
strptime()	Parse the time/date generated by strftime().
strtotime()	Parses any English text date or time description into a Unix timestamp.
time()	Returns the Unix timestamp of the current time.
timezone_abbreviations_list()	Returns an associative array containing daylight saving time, offset, and time zone name.
timezone_identifiers_list()	Returns a numeric array with all time zone identifiers.
timezone_location_get()	Returns the location information of the specified time zone.
timezone_name_from_ abbr()	Returns the time zone name based on the time zone abbreviation.
timezone_name_get()	Returns the name of the time zone.
timezone_offset_get()	Returns the time zone offset relative to GMT.
timezone_open()	Create a new DateTimeZone object.
timezone_transitions_get()	Returns all transitions for time zones.
timezone_version_get()	Returns the version of the time zone database.

PHP 5 predefined Date/Time constants

Constant	Description
DATE_ATOM	Atom (for example: 2005-08-15T16:13:03+0000)
DATE_COOKIE	HTTP Cookies (for example: Sun, 14 Aug 2005 16:13:03 UTC)
DATE_ISO8601	ISO-8601 (for example: 2005-08-14T16:13:03+0000)
DATE_RFC822	RFC 822 (Example: Sun, 14 Aug 2005 16:13:03 UTC)
DATE_RFC850	RFC 850 (Example: Sunday, 14-Aug-05 16:13:03 UTC)
DATE_RFC1036	RFC 1036 (Example: Sunday, 14 -Aug-05 16:13:03 UTC)
DATE_RFC1123	RFC 1123 (Example: Sun, 14 Aug 2005 16:13:03 UTC)
DATE_RFC2822	RFC 2822 (Example: Sun, 14 Aug 2005 16:13:03 +0000)
DATE_RSS	RSS (Example: Sun, 14 Aug 2005 16:13:03 UTC)
DATE_W3C	World Wide Web Consortium (Example: 2005-08-14T16:13 :03+0000)