note 51328 added to function.date

PHP date, strftime and mktime functions are DST sensitive This means if the server is setup to be US GMT-5 and DST sensitive then the mentioned functions add, extract or do nothing with the current DST. Without a given timestamp: - date() uses the current server time. This is DST affected if the server uses DST settings - gmdate() uses the current GMT time, it extracts server GMT & DST. With a given timestamp: - date() is affected if the server uses DST settings * if current time is DST but the given time isn't then DST is extracted * if current time isn't DST but the given time is then DST is added - gmdate() is affected, it extracts server GMT & DST on the given timestamp So for example $timestamp is a GMT based time. You modify the $timestamp for a "member" his personal timezone and dst. The member has setup GMT-5 and DST sensitive You add his GMT-5 to the $timestamp and check if the $timestamp is in DST or not Then all the above functions are screwed in normal use. <?php $timestamp = 1122814800; // 07/31/05 13:00:00 GMT $user_gmt = -5; $user_dst = 1; $timestamp += ($user_gmt*3600); // to user time $timestamp += 3600; // user time is in DST echo date("H:i:s",$timestamp); echo gmdate("H:i:s",$timestamp); ?> If server is GMT+0 in summer (DST is on) the above outputs 08:00:00 07:00:00 If server is GMT+0 in winter (DST is off) the above outputs 09:00:00 08:00:00 If server is GMT-5 in winter (DST is off) the above outputs 09:00:00 03:00:00 So if you work with local times and the server isn't GMT based be carefull how you output the times to your members. ---- Manual Page -- http://www.php.net/manual/en/function.date.php Edit -- http://master.php.net/manage/user-notes.php?action=edit+51328 Delete: added to the manual -- http://master.php.net/manage/user-notes.php?action=delete+51328&report=yes&reason=added+to+the+manual Delete: bad code -- http://master.php.net/manage/user-notes.php?action=delete+51328&report=yes&reason=bad+code Delete: spam -- http://master.php.net/manage/user-notes.php?action=delete+51328&report=yes&reason=spam Delete: useless -- http://master.php.net/manage/user-notes.php?action=delete+51328&report=yes&reason=useless Delete: other reasons -- http://master.php.net/manage/user-notes.php?action=delete+51328&report=yes Reject -- http://master.php.net/manage/user-notes.php?action=reject+51328&report=yes Search -- http://master.php.net/manage/user-notes.php