Note that this is not the right way to initiate a \DateTimeImmutable object with a numeric Unix timestamp.
<?php
// Wrong, despite the documention *kind of* alluding to it
$obj = \DateTimeImmutable::setTimestamp(time() - 1);
// Also won't work
$obj = new \DateTimeImmutable(time() - 1)
// Correct, works, clean single line
$obj = (new \DateTimeImmutable())->setTimestamp(time() - 1);
?>
... In fact, this is a non-static method and thus should not be called statically.