<?php
$timestamp = NULL;
$date = (new DateTime())->setTimestamp($timestamp);
// Almost hit the bug, but why was it 1969?
echo $date->format('U = Y-m-d H:i:s') . "\n";
// Because we live in a negative offset from UTC.
$date->setTimezone(new DateTimeZone('America/Chicago'));
echo $date->format('U = Y-m-d H:i:s') . "\n";
Deprecated: DateTime::setTimestamp(): Passing null to parameter #1 ($timestamp) of type int is deprecated in /in/oqrAr on line 5
0 = 1970-01-01 01:00:00
0 = 1969-12-31 18:00:00