DateTimeImmutable and DateTime objects can be compared using comparison operators, however `==` and `===` produce different results:
<?php
var_dump(new DateTimeImmutable('2012-10-10') === new DateTimeImmutable('2012-10-10'));
// false
?>
BUT:
<?php
var_dump(new DateTimeImmutable('2012-10-10') == new DateTimeImmutable('2012-10-10'));
// true
?>