DateTime('first day of April') returns same as DateTime('first day of May')

Question

April ant May returns same date in php:

var_dump(new DateTime('first day of April')); - '2016-05-01 00:00:00'

var_dump(new DateTime('first day of May')); - '2016-05-01 00:00:00'

Works great for other months, but for April it returns 05 instead of 04.

Edit: 'timezone' => 'Europe/Paris'

Edit2: http://imgur.com/TccRcMo

Answer 1

This is a very strange behavior, but I found some solutions to get the expected results. The reason why this is not working is the missing year on the DateTime object.

solution #1 (https://3v4l.org/hIA89)

<?php
    $datetime = new DateTime('2016-01-01', new DateTimeZone('Europe/Paris'));
    var_dump($datetime->modify('first day of april'));
    var_dump($datetime->modify('first day of may'));
?>

solution #2 (https://3v4l.org/PDXM3)

<?php
    var_dump(new DateTime('first day of april 2016', new DateTimeZone('Europe/Paris')));
    var_dump(new DateTime('first day of may 2016', new DateTimeZone('Europe/Paris')));
?>

solution #3 (https://3v4l.org/pBH0n)

<?php
    var_dump(new DateTime('1 april', new DateTimeZone('Europe/Paris')));
    var_dump(new DateTime('1st april', new DateTimeZone('Europe/Paris')));
    var_dump(new DateTime('1 may', new DateTimeZone('Europe/Paris')));
    var_dump(new DateTime('1st may', new DateTimeZone('Europe/Paris')));
?>

thx to @Glavic