public function calcEndDateTimeBasedOnDuration()
    {
        $duration = $this->Duration;
        $secs = (substr($duration, 0, 2) * 3600) + (substr($duration, 3, 2) * 60);

        $startDate = strtotime($this->StartDateTime);
        $endDate = $startDate + $secs;
        $formatDate = date("Y-m-d H:i:s", $endDate);

        return $formatDate;
    }