Apache and Symfony date.timezone error
Please see David Jacquel correct solution below !
I leave this answer for historical purposes...
In sf1, I ran through this and got it fixed with a
date_default_timezone_set('Europe/Madrid');
in the bootstrap (that was ProjectConfiguration.class.php).
In sf2 you may modify the web/app.php file to insert the same piece of code. It is a bit hackyish, but will get you up and running.