Constants for the newly added date function in PHP5_PHP Tutorial

After php5.1.1, the date function adds the following constants.

Since PHP 5.1.1, the following constants are defined to provide standard date expression methods, which can be used in date format functions (such as date()).

DATE_ATOM (string)
Atomic clock format (such as: 2005-08-15T15:52:01+00:00)

DATE_COOKIE (string)
HTTP Cookies format (such as: Mon, 15 Aug 2005 15:52:01 UTC)

DATE_ISO8601 (string)
ISO-8601 (such as: 2005-08-15T15:52:01+0000)

DATE_RFC822 (string)
RFC 822 (eg: Mon, 15 Aug 2005 15:52:01 UTC)

DATE_RFC850 (string)
RFC 850 (eg: Monday, 15-Aug-05 15:52:01 UTC)

DATE_RFC1036 (string)
RFC 1036 (eg: Monday, 15-Aug-05 15:52:01 UTC)

DATE_RFC1123 (string)
RFC 1123 (eg: Mon, 15 Aug 2005 15:52:01 UTC)

DATE_RFC2822 (string)
RFC 2822 (eg: Mon, 15 Aug 2005 15:52:01 +0000)

DATE_RSS (string)
RSS (eg: Mon, 15 Aug 2005 15:52:01 UTC)

DATE_W3C (string)
World Wide Web Consortium (eg: 2005-08-15T15:52:01+00:00)

For example, to output the date format required by RSS, you can simply use the following code:

echo date(DATE_RSS);