public function setCreatedOn($created_on) {
        
        $this -> created_on = $created_on !== null ? new \DateTime($created_on) : null;
        return $this;
    }
public function setCreatedOn($created_on) {
        
        $this -> created_on = $created_on !== null ? new \DateTime($created_on) : null;
        return $this;
    }
public function setCreatedOn ( $ created_on ) { $ this -> created_on = $ created_on !== null ? new \ DateTime ( $ created_on ) : null ; return $ this ; }
Sets the created on
@param string $created_on
@return TimestampAwareTrait
Sets the created on