I run OpenX (an open source ad serving platform) under IIS and PHP …. but after upgrading to PHP 5.3 noticed the following error appearing in the PHP error logs file (c:\windows\temp\php-errors.log by default).
PHP Warning: date_default_timezone_get(): It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'Europe/London' for '1.0/DST' instead in C:\inetpub\wwwroot\openx-2.8.5\www\delivery\spc.php on line 191
The solution to make this error go away is simply to specify a default timezone in the php.ini configuration file. In my case this looked like:
[Date] ; Defines the default timezone used by the date functions ; http://php.net/date.timezone date.timezone = "Europe/London"