Somar Horas

soma_horas.php

<?php

function soma_horas() {
    $i = $s = $hour = $min = $sec = 0;
    foreach (func_get_args() as $time) {
       sscanf($time, '%d:%d:%d', $hour, $min, $sec);
       $i += ($hour * 60) + $min + ($sec / 60);
       $s += $sec;
    }

    if ($h = floor($i / 60)) {
        $i %= 60;
        $s %= 60;
    }
    return sprintf('%02d:%02d:%02d', $h, $i, $s);
}


echo soma_horas('01:50:50', '30:10:30', '02:10:15'); #34:11:35