Thread:Project:Support desk/Installation,/reply (5)

Please don't modify Setup.php. Adding  (Or whatever the timezone you want is) to the bottom of LocalSettings.php will accomplish the same thing, without modifying core files.

The issue in question (the warning) will be fixed in MediaWiki 1.21. You can also fix the issue by applying the one line fix to GlobalFunctions.php or just disabling E_STRICT warnings in your php.ini file.