Kurt\Google\Analytics\Analytics::setupDates PHP Method

    private function setupDates($startDate = null, $endDate = null)
    {
        $start = (new Carbon('first day of last month'))->hour(0)->minute(0)->second(0);
        $end = (new Carbon('last day of last month'))->hour(23)->minute(59)->second(59);
        return $this->setPeriod(new Period($start, $end));
    }