public function isBetween(Date $dt1, Date $dt2, $equal = true)
    {
        if ($dt1->isAfter($dt2)) {
            $temp = $dt1;
            $dt1 = $dt2;
            $dt2 = $temp;
        }

        if ($equal) {
            return $this->isAfterOrEquals($dt1) && $this->isBeforeOrEquals($dt2);
        }

        return $this->isAfter($dt1) && $this->isBefore($dt2);
    }