- var_dump: documentation ( source)
<?php
$date = (new DateTime())->format('Y-m-d H:i:s');
$next = (new DateTime('+10 minutes'))->format('Y-m-d H:i:s');
echo $date . "\n";
echo $next . "\n";
var_dump($date >= $next);
var_dump($date <= $next);
var_dump($date > $date);