public function getAvailableFrom()
    {
        if ($this->AvailableFromDate) {
            return $this->dbObject('AvailableFromDate');
        } elseif ($startDate = $this->getEventStartDate()) {
            $lastWeek = new Date();
            $lastWeek->setValue(strtotime(self::config()->get('sale_start_threshold'), strtotime($startDate->value)));
            return $lastWeek;
        }

        return null;
    }