note 95564 added to function.date-default-timezone-set

I experienced that using this function highly increases performance of functions like getdate() or date() using PHP 5.2.6 on Windows. I experienced similar results on Linux servers with PHP 5.2.6 and 5.2.10, although the difference was not that significant on these servers: The PHP 5.2.10 server did run with date_default_timezone_set ("only") twice as fast as without. The 5.2.6 server did 5 times faster with date_default_timezone_set. As you can see below, the 5.2.6-Windows machine did a LOT faster. Of course these machines have completely different hardware and can not really be compared, but all show improved performance. I checked PHP 4.4.9 on Windows (without date_default_timezone_set of course) and noticed that its as fast as PHP 5.2.6 with date_default_timezone_set. The following script shows this: <?php # uncomment to see difference # date_default_timezone_set(date_default_timezone_get()); function getmicrotime() { list($usec, $sec) = explode(' ',microtime()); return ($sec.substr($usec,1,7)); } $start=mktime(0,0,0,1,1,2005); $end=mktime(0,0,0,1,1,2020); $nr=50000; $start_time=getmicrotime(); for($i=0;$i<$nr;$i++) { # $value=getdate(rand($start,$end)); date("H:i:s d.m.Y",rand($start,$end)); } $end_time=getmicrotime(); echo "Time: ".($end_time-$start_time); // With date_default_timezone_set(): "Time: 0.379343986511" // Without date_default_timezone_set(): "Time: 7.4971370697" ?> Note that the timezone is not changed, it is only set again. I really wonder why this makes such a big performance difference, but its good to know. ---- Server IP: 69.147.83.197 Probable Submitter: 91.45.113.100 ---- Manual Page -- http://www.php.net/manual/en/function.date-default-timezone-set.php Edit -- https://master.php.net/note/edit/95564 Del: integrated -- https://master.php.net/note/delete/95564/integrated Del: useless -- https://master.php.net/note/delete/95564/useless Del: bad code -- https://master.php.net/note/delete/95564/bad+code Del: spam -- https://master.php.net/note/delete/95564/spam Del: non-english -- https://master.php.net/note/delete/95564/non-english Del: in docs -- https://master.php.net/note/delete/95564/in+docs Del: other reasons-- https://master.php.net/note/delete/95564 Reject -- https://master.php.net/note/reject/95564 Search -- https://master.php.net/manage/user-notes.php