Casting from parent class to child

[Teto <mattator@xxxxxxxxx>]

Hi,

I'm trying to extends the base class DateTime.
parent::createFromFormat("H.i d.m.Y", $string); returns a DateTime and I
want to convert it into a DateTimePlus (my own extended class). What's the
best way to do this plz ?

Some code:
class DateTimePlus extends DateTime

{
        static function setFromGUIDateAndTime($date,$time ){

        $string = $time.' '.$date;
        //echo 'str:'.$string;
        $res = parent::createFromFormat("H.i d.m.Y", $string);
        return (DateTimePlus)parent::createFromFormat("H.i d.m.Y", $string);

    }


Thk you

matt