<?php
$time1 = "today 23:45";
$time2 = "tomorrow 01:24";

$diff = abs(strtotime($time1) - strtotime($time2));

$tmins = $diff/60;

$hours = floor($tmins/60);

$mins = $tmins%60;


echo "<b>$hours</b> hours and<b>$mins</b> minutes</b>";
?>

<b>1</b> hours and<b>39</b> minutes</b>