Predefined Constants

The following constants are defined since PHP 5.1.1 and they offer standard date representations, which can be used along with the date format functions (like date()).

DATE_ATOM (string)

Atom (example: 2005-08-15T15:52:01+00:00)

DATE_COOKIE (string)

HTTP Cookies (example: Monday, 15-Aug-05 15:52:01 UTC)

DATE_ISO8601 (string)

ISO-8601 (example: 2005-08-15T15:52:01+0000)

DATE_RFC822 (string)

RFC 822 (example: Mon, 15 Aug 05 15:52:01 +0000)

DATE_RFC850 (string)

RFC 850 (example: Monday, 15-Aug-05 15:52:01 UTC)

DATE_RFC1036 (string)

RFC 1036 (example: Mon, 15 Aug 05 15:52:01 +0000)

DATE_RFC1123 (string)

RFC 1123 (example: Mon, 15 Aug 2005 15:52:01 +0000)

DATE_RFC2822 (string)

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

DATE_RFC3339 (string)

Same as DATE_ATOM (since PHP 5.1.3)

DATE_RSS (string)

RSS (Mon, 15 Aug 2005 15:52:01 +0000)

DATE_W3C (string)

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

Following constants exists since PHP 5.1.2 and specify a format returned by functions date_sunrise() and date_sunset().

SUNFUNCS_RET_TIMESTAMP (integer)

Timestamp

SUNFUNCS_RET_STRING (integer)

Hours:minutes (example: 08:02)

SUNFUNCS_RET_DOUBLE (integer)

Hours as floating point number (example 8.75)