Set the value of this object to a Datetime whose "date" part has the value represented by the specified date, and whose "time" part has the value represented by the optionally specified hour, minute, second, millisecond, and microsecond attributes, if the attribute values (collectively) represent a valid Datetime value (see isValid). Unspecified trailing optional parameters default to 0. Return 0 on success, and a non‐zero value (with no effect) otherwise.