public function weekly()
    {
        $this->setScheduleMonth(self::ANY);
        $this->setScheduleWeek(self::ANY);
        $this->setScheduleDayOfMonth(self::ANY);
        $this->setScheduleDayOfWeek(Day::SUNDAY);
        $this->setScheduleHour(0);
        $this->setScheduleMinute(0);

        return $this;
    }