- date_default_timezone_set: documentation ( source)
- explode: documentation ( source)
- date: documentation ( source)
<?php
$time ="25:00";
$days = 3;
list($hours, $minutes) = explode(":", $time);
$minutes += $hours*60;
$seconds = $minutes*60;
date_default_timezone_set ("UTC");
echo "new time: " . date("h:i", $seconds/$days);