<?php

$createdAt = new \DateTime();

echo $createdAt->format('d.m.Y h:i:s'). "\n";


$fiveMinLater = (clone $createdAt)->add(new \DateInterval('PT5M'));

echo $fiveMinLater->format('d.m.Y h:i:s') . "\n";

$diff = $fiveMinLater->diff($createdAt)->format('%i');

if ((int)$diff == 5){
    echo "Different is 5 minutes \n";
}