<?php
$firstDayJuly2016 = new DateTime("first day of July 2016");
// The following returns
// object(DateTime)
// public 'date' => string '2016-07-02 00:00:00' (length=19)
var_dump($firstDayJuly2016);
$fourthDayJuly2016 = new DateTime("July 2016 +4 days");
// The following returns
// object(DateTime)
// public 'date' => string '2016-07-05 00:00:00' (length=19)
var_dump($fourthDayJuly2016);