When trying to create DateInterval with 2376000 seconds (exactly 660 hours), newly created object returns interval equal to 659 hours. It works fine for smaller numbers, but above certain value it just loses somewhere 1 hour.
$interval = new DateInterval('PT2376000S');
What it returns:
DateInterval {
interval: + 27d 11:00:00.0
+"s": 2376000
}
Using PHP 7.4.