PHP Date / Time Functions

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# PHP Date / Time Functions

## PHP Date / Time Introduction

The date/time functions allow you to extract and format the date and time on the server.

Note: These functions depend on the locale settings of the server!

## Installation

The date/time functions are part of the PHP core. There is no installation needed to use these functions.

## Runtime Configuration

The behavior of the date/time functions is affected by settings in php.ini.

Date/Time configuration options:

Name | Default | Description | Changeable
--- | --- | --- | ---
date.default_latitude | "31.7667" | Specifies the default latitude (available since PHP 5). This option is used by date_sunrise() and date_sunset() | PHP_INI_ALL
date.default_longitude | "35.2333" | Specifies the default longitude (available since PHP 5). This option is used by date_sunrise() and date_sunset() | PHP_INI_ALL
date.sunrise_zenith | "90.83" | Specifies the default sunrise zenith (available since PHP 5). This option is used by date_sunrise() and date_sunset() | PHP_INI_ALL
date.sunset_zenith | "90.83" | Specifies the default sunset zenith (available since PHP 5). This option is used by date_sunrise() and date_sunset() | PHP_INI_ALL
date.timezone | "" | Specifies the default timezone (available since PHP 5.1) | PHP_INI_ALL

## PHP Date / Time Functions

PHP: indicates the earliest version of PHP that supports the function.

Function | Description | PHP
--- | --- | ---
checkdate() | Validates a Gregorian date | 3
date_default_timezone_get() | Returns the default time zone | 5
date_default_timezone_set() | Sets the default time zone | 5
date_sunrise() | Returns the time of sunrise for a given day / location | 5
date_sunset() | Returns the time of sunset for a given day / location | 5
date() | Formats a local time/date | 3
getdate() | Returns an array that contains date and time information for a Unix timestamp | 3
gettimeofday() | Returns an array that contains current time information | 3
gmdate() | Formats a GMT/UTC date/time | 3
gmmktime() | Returns the Unix timestamp for a GMT date | 3
gmstrftime() | Formats a GMT/UTC time/date according to locale settings | 3
idate() | Formats a local time/date as integer | 5
localtime() | Returns an array that contains the time components of a Unix timestamp | 4
microtime() | Returns the microseconds for the current time | 3
mktime() | Returns the Unix timestamp for a date | 3
strftime() | Formats a local time/date according to locale settings | 3
strptime() | Parses a time/date generated with strftime() | 5
strtotime() | Parses an English textual date or time into a Unix timestamp | 3
time() | Returns the current time as a Unix timestamp | 3

## PHP Date / Time Constants

PHP: indicates the earliest version of PHP that supports the constant.

Constant | Description | PHP
--- | --- | ---
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) |

From http://www.w3schools.com (Copyright Refsnes Data)