It's 112 throughout Europe.
Except, the only standard International Date Format that makes any sense (and alleviates the entire confusion between the two commonly-used month-first and day-first date formats) is ISO-8601 — the "you're both wrong!" YYYY-MM-DD HH:MM:SS format.It sorts properly without special parsing, it's completely unambiguous, it's your new best friend. (And it doesn't permit the use of slashes in the date component, to further differentiate itself from the Two Evil Formats™.)Unfortunately, ISO-8601 (in the interests of precision/unambiguity) makes no allowances for yearless dates.Which is why the HTML5 Specification, § 188.8.131.52 Yearless Dates, builds on the RFC3339 subset of ISO-8601 by defining a supported format for dates without years. Sensibly, they follow the most-significant-to-least-significant-component ordering of ISO-8601, meaning that the supported HTML5 Time-datetime format for a yearless date is "MM-DD". (Two digits are always required, so "9-11" is not actually a valid HTML5 date. It would have to be "09-11".)Sorry!