laravel dates and time substraction code example
Example: laravel subtract date
$start_time = \Carbon\Carbon::parse($request->input('start_time'));
$finish_time = \Carbon\Carbon::parse($request->input('finish_time'));
$price = $request->input('price');
$result = $start_time->diffInDays($finish_time, false);
if ($result < 0) {
$price = $price * $result;
}