Please check following path if you are use linux OS
vi /etc/php5/cli/php.ini and change date.timezone then restart apache.. I hope your problem will be solve. Please let me know if you face issue
Or you can put code in your app_dev.php and app.php file which are located at web directory
ini_set('date.timezone', 'Europe/Paris'); date_default_timezone_set("Europe/Paris");