- date_diff: documentation ( source)
- var_dump: documentation ( source)
<?php
$change = 1453404531;
$then = new DateTime("@$change");
var_dump($then->format('Y-m-d H:i:s e'));
$now = new DateTime();
$interval = date_diff($now, $then);
echo $then;
echo $now;
echo $interval;