public function getPasswordAge()
    {
        $date = \MUtil_Date::ifDate(
                $this->_getVar('user_password_last_changed'),
                array(\Gems_Tracker::DB_DATETIME_FORMAT, \Gems_Tracker::DB_DATE_FORMAT, \Zend_Date::ISO_8601)
                );
        if ($date instanceof \MUtil_Date) {
            return abs($date->diffDays());
        } else {
            return 0;
        }
    }