I agree with the last two, but to me the first is confusing already, as Europe uses different puntuation everywhere :(

The dotted DD.MM.YYYY seems to be popular in older EU documents and Post-Soviet states.

In The Netherlands we use DD-MM-YYYY.

I think that we are blessed anyway, as Ireland is a lost cause: "In Ireland, the date is written in the order "day month year", with the separator as a stroke, dot, hyphen, or just left blank. The year may be written with four digits or just the final two, sometimes with an apostrophe to mark the omitted first two digits."

Conclusion: Disambiguate and use ISO! (but whatever you use, never use / and/or D in the middle.)