How to get the total hour from starting time to end time in php

Question

How can I get the total hour from start time to end time.

   $start_time = '11:00:00 PM'; // as of 07/08/2013
   $end_time   = '01:00:00 AM'; // as of 08/08/2013

Then output should be:

   $total = '02:00:00'; // 12 hour format

Answer 1

You can convert the date strings to time values, then subtract to get the difference in seconds between the two, then simply divide by 3600 to get the difference in hours:

$t1 = strtotime('2013-08-07 23:00:00');
$t2 = strtotime('2013-08-08 01:00:00');
$differenceInSeconds = $t2 - $t1;
$differenceInHours = $differenceInSeconds / 3600;

Answer 2

If you want to find out the total time and you only have time values go for this. //24 hour format

    for ($i = 0; $i < count($array); $i++) { //array contains your sorted times like [H:i]
        $a = $array[$i]. " " .date("Y/m/d");
        $array[$i] = $a;
    }
    
    $total=0;
    for ($i = count($array); $i>1; $i--){
        if ($array[$i-1] < $array[$i-2]){
            $array[$i-1] = strtotime("+1 day", strtotime($array[$i-1]));
            $z = "a";
        }
        $a = strtotime($array[$i-1]);
        $b = strtotime($array[$i-2]);
        $diff = $a - $b;    
        $hours = ceil($diff / (24*60));
        $total += date("H", $hours);
    }
if ($z == "a"){
    $total += date("H", ceil(strtotime($array[0]) / (24*60)));
}