PHP DateTime class Namespace I'm use the symfony2 framework and I want to use the PHP's DateTime class (PHP version is 5.3). Here the statement: namespace SDCU\GeneralBundle\Entity; class Country {    public function __construct(){        $this->insertedAt = new DateTime();    } } But, when execute this constructor, I get an error saying that there's no "SDCU\GeneralBundle\Entity\DateTime" class. I've been searching around for DateTime's namespace but with no success... any idea?  Answer: DateTime is in the global namespace, and as "classnames always resolve to the