Assuming that this is a real issue that should be fixed in the standards (which I don't agree, btw), I think the month should use a separate set of symbols to be distinct, which sadly implies some kind of additional knowledge besides from Hindu-Arabic numerals (but not necessarily English). A compromise can be also made if we all accept that month numbers can be arbitrary, e.g. 33--36, 43--46, 53--56 for 12 months. Prefixes or suffixes wouldn't work well because people would then confuse which one is month and which one is day of the month; by using an entirely different set of month symbols, a fresh connection can be made instead.