I solved the problem with the solution here: http://blogs.iis.net/ruslany/archive/2009/06/12/upgrade-to-wordpress-2-8-and-php-5-3-on-iis-7.aspx What you need to do is just set the time zone in php.ini! e.g. date.timezone = Etc/GMT+10 http://us3.php.net/manual/en/timezones.php