- var_dump: documentation ( source)
<?php
$from = new \DateTime( 'now', new \DateTimezone('Europe/Helsinki') );
$from->modify( 'first day of this month' );
$from->setTime(0,0,0);
$from->setTimezone( new \DateTimeZone( 'UTC' ) );
$from2 = clone $from;
$mongoTime = $from2->getTimestamp();
var_dump($from);
var_dump($from2);