- date: documentation ( source)
- strtotime: documentation ( source)
<?php
$total = array('01:00:00','02:20:00','04:00','05:10');
$sum = strtotime('00:00:00');
$sum2=0;
foreach ($total as $v){
$sum1=strtotime($v)-$sum;
$sum2 = $sum2+$sum1;
}
$sum3=$sum+$sum2;
echo date("H:i:s",$sum3);