working with \DateTime

gistfile1.php

<?php

date_default_timezone_set('UTC');
$micro = explode(" ", microtime());
$micros = substr($micro[0], 1, 7);
$date = date('Y-m-d H:m:i');
$dtString = $date . $micros;
$datetime = DateTime::createFromFormat('Y-m-d H:m:i.u', $dtString, new DateTimeZone('UTC'));
$datetime2 = new DateTime($dtString, new DateTimeZone('UTC'));
$datetime3 = new DateTime("now", new DateTimeZone('UTC'));

var_dump($datetime3->format('Uu'));
var_dump($datetime2->format('Uu'));
var_dump($dtString);
var_dump($datetime->format('Uu'));
//var_dump(DateTime::getLastErrors());