If $datetime value is `null`, empty string, or whitespace(s), it will default to the current datetime or 'now'.<?php$date = null; // or '' or ' 'var_dump(date_create($date));?>returns<?phpobject(DateTime)#1 (3) { ["date"]=> string(26) "2025-07-29 00:59:02.992777" ["timezone_type"]=> int(3) ["timezone"]=> string(3) "UTC"}?>