[PHP-DOC] docs for php date("I", $timestamp) for daylight savings

[Steve Chamberlin]

Hi, The docs to PHP's date() function are unclear regarding the "I" format string. They say date("I", $timestamp) returns whether or not $timestamp is in daylight savings time: 1 if daylight savings time, 0 otherwise. Trouble is, the docs don't explain how date() decides if a given timestamp is in daylight savings time. DST starts and ends on different dates in different political regions of the world. Does it use the DST rules for the United States? Does it matter whether or not the server is itself located in a region that observes daylight savings time?