Carbon get difference in hour from to specific start and end datetime
$meeting_start = $meeting->start_date . ' ' . $meeting->start_time;
$meeting_end = $meeting->end_date . ' ' . $meeting->end_time;
$meeting_start_time = Carbon::parse($meeting_start);
$meeting_end_time = Carbon::parse($meeting_end);
$meeting_duration = $meeting_end_time->diffInHours($meeting_start_time);