php datetime add seconds code example

Example 1: how to add hour minute seconds in php datetime

date('Y-m-d H:i',strtotime('+1 hour +20 minutes',strtotime($start)));

Example 2: add 1 day php datetime

$date = new DateTime('2000-01-01');
$date->add(new DateInterval('P1D'));

Example 3: add seconds to datetime php

<?php 
$date = new DateTime();
echo $date->getTimestamp(). "<br>";
$date->add(new DateInterval('PT674165S')); // adds 674165 secs
echo $date->getTimestamp();
?>