PHP 5 Date/Time Functions

PHP Date/Time Introduction

The date/time functions allow you to get the date and time from the server where your PHP script runs. You can then use the date/time functions to format the date and time in several ways.

Note: These functions depend on the locale settings of your server. Remember to take daylight saving time and leap years into consideration when working with these functions.

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Installation

The PHP date/time functions are part of the PHP core. No installation is required to use these functions.

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Runtime Configuration

The behavior of these functions is affected by settings in php.ini:

Name	Description	Default	PHP Version
date.timezone	The default timezone (used by all date/time functions)	""	PHP 5.1
date.default_latitude	The default latitude (used by date_sunrise() and date_sunset())	"31.7667"	PHP 5.0
date.default_longitude	The default longitude (used by date_sunrise() and date_sunset())	"35.2333"	PHP 5.0
date.sunrise_zenith	The default sunrise zenith (used by date_sunrise() and date_sunset())	"90.83"	PHP 5.0
date.sunset_zenith	The default sunset zenith (used by date_sunrise() and date_sunset())	"90.83"	PHP 5.0

PHP 5 Date/Time Functions

Function	Description
checkdate()	Validates a Gregorian date
date_add()	Adds days, months, years, hours, minutes, and seconds to a date
date_create_from_format()	Returns a new DateTime object formatted according to a specified format
date_create()	Returns a new DateTime object
date_date_set()	Sets a new date
date_default_timezone_get()	Returns the default timezone used by all date/time functions
date_default_timezone_set()	Sets the default timezone used by all date/time functions
date_diff()	Returns the difference between two dates
date_format()	Returns a date formatted according to a specified format
date_get_last_errors()	Returns the warnings/errors found in a date string
date_interval_create_from_date_string()	Sets up a DateInterval from the relative parts of the string
date_interval_format()	Formats the interval
date_isodate_set()	Sets the ISO date
date_modify()	Modifies the timestamp
date_offset_get()	Returns the timezone offset
date_parse_from_format()	Returns an associative array with detailed info about a specified date, according to a specified format
date_parse()	Returns an associative array with detailed info about a specified date
date_sub()	Subtracts days, months, years, hours, minutes, and seconds from a date
date_sun_info()	Returns an array containing info about sunset/sunrise and twilight begin/end, for a specified day and location
date_sunrise()	Returns the sunrise time for a specified day and location
date_sunset()	Returns the sunset time for a specified day and location
date_time_set()	Sets 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()	Sets the time zone for the DateTime object
date()	Formats a local date and time
getdate()	Returns date/time information of a timestamp or the current local date/time
gettimeofday()	Returns the current time
gmdate()	Formats a GMT/UTC date and time
gmmktime()	Returns the Unix timestamp for a GMT date
gmstrftime()	Formats a GMT/UTC date and time according to locale settings
idate()	Formats a local time/date as integer
localtime()	Returns the local time
microtime()	Returns the current Unix timestamp with microseconds
mktime()	Returns the Unix timestamp for a date
strftime()	Formats a local time and/or date according to locale settings
strptime()	Parses a time/date generated with strftime()
strtotime()	Parses an English textual datetime into a Unix timestamp
time()	Returns the current time as a Unix timestamp
timezone_abbreviations_list()	Returns an associative array containing dst, offset, and the timezone name
timezone_identifiers_list()	Returns an indexed array with all timezone identifiers
timezone_location_get()	Returns location information for a specified timezone
timezone_name_from_ abbr()	Returns the timezone name from abbreviation
timezone_name_get()	Returns the name of the timezone
timezone_offset_get()	Returns the timezone offset from GMT
timezone_open()	Creates new DateTimeZone object
timezone_transitions_get()	Returns all transitions for the timezone
timezone_version_get()	Returns the version of the timezone db

PHP 5 Predefined Date/Time Constants

Constant	Description
DATE_ATOM	Atom (example: 2005-08-15T16:13:03+0000)
DATE_COOKIE	HTTP Cookies (example: Sun, 14 Aug 2005 16:13:03 UTC)
DATE_ISO8601	ISO-8601 (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 (Sun, 14 Aug 2005 16:13:03 +0000)
DATE_RSS	RSS (Sun, 14 Aug 2005 16:13:03 UTC)
DATE_W3C	World Wide Web Consortium (example: 2005-08-14T16:13:03+0000)

Credit: www.w3schools.com