Add hours which are in G:i format php

Question

I currently have a list of time diffs in G:i format.

I would like to add them all up but when i try to it resets at 24 back to 0. How can i get a result like: 54:45 for example?

Thanks in advance.

date_default_timezone_set('UTC');
$username = $row['username'];
$begintime = $row['begintime'];
$endtime = $row['endtime'];

$begintime = new DateTime($begintime);
$begintime = $begintime->format('H:i');

$endtime = new DateTime($endtime);
$endtime = $endtime->format('H:i');

$difference = strtotime($endtime) - strtotime($begintime);
$difference = date('G:i', $total);  
$total_hours += $difference;  

Answer 1

Don't use date() to format absolute times. Since $difference contains the time difference in seconds, it's just a matter of simple arithmetics:

$hours = floor( $difference / 60 / 60 );
$minutes = ( $difference / 60 ) % 60;

echo "$hours:$minutes";  

Answer 2

You can actually "trick" DateTime into doing absolute times by adding the differences to an arbitrary date:

$foo = new DateTime();
$bar = new DateTime();

foreach ($intervals as $interval) {
    $begin = $interval['begin'];
    $end = $interval['end'];
    $foo->add($begin->diff($end));
}

// Will be the total time of all intervals, as an interval itself
$total = $foo->diff($bar);