Ошибка "It is not safe to rely on the system's timezone settings" в PHP 5.3

Warning: strftime(): 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/Moscow' for 'MSK/4.0/no DST' instead in

@date_default_timezone_set('Europe/Moscow');