php: datetime() difference between 2 datetime with 2 variables

Question

I have in my database 4 columns which are:

Date_in | Time_in | Date_out | Time_out

Date_in and Time_in belong together (e.g., 2013-02-18 13

Answer 1

$start_time = new DateTime("$list[date_in] " . "$list[time_in]");
$since_start = $start_time->diff(new DateTime("$list[date_out] " . "$list[time_out]"));

OR

$start_time = new DateTime("{$list['date_in']} {$list['time_in']}");
$since_start = $start_time->diff(new DateTime("{$list['date_out']} {$list['time_out']}"));