pyiso8601 reads ordinal date 2023-216 as Feb 16, no error

iso8601 2.1.0 (micktwomey/pyiso8601 master 00c9262) doesn't support ISO ordinal dates, but instead of rejecting YYYY-DDD its regex takes -2 as a one-digit extended month and 16 as a basic day: parse_date('2023-216') returns 2023-02-16 (the real date is Aug 4), and is_iso8601('2023-216') is True. About 14% of valid ordinal strings come back as a wrong date this way; the rest raise. It also accepts mixed forms like '2023-1231'. Fix: a regex conditional (?(monthdash)-(?P<daydash>..)|(?P<day>..)) so the day's separator style follows the month's; the upstream suite still passes (single-digit '2007-5-7' still works). If you take timestamps from producers that might emit %Y-%j, use datetime.fromisoformat (which rejects them) or ciso8601/dateutil (which parse them correctly).