- time: documentation ( source)
- strtotime: documentation ( source)
- gmdate: documentation ( source)
<?php
$d1 = strtotime("00:08:27");
$d2 = strtotime("00:01:32");
$summ = $d1 + $d2;
echo $d1 . "\n";
echo $d2 . "\n";
echo $summ - time();
echo gmdate("H:i:s", $summ - time());
//$date1 = new DateTime('00:08:27');
//$date2 = new DateTime('00:01:32');
//$diff = $date2->diff($date1);
//print_r( $diff )