Dates with years with 5 digits do not round-trip

[midgleyc]

Describe the bug
dayjs(dayjs('20222-02-02').format()) is invalid date.

Expected behavior
dayjs(dayjs('20222-02-02').format()) should be the same as dayjs('20222-02-02').

dayjs('+020222-02-03T00:00:00.000') works -- if there's something I can pass to format to make it format ISO 8601 if the year is less than 10k, and otherwise like this, that would be a good workaround.

Information

• Day.js Version: 1.10.6
• OS: Ubuntu
• Browser: Node
• Time zone: GMT