The what's new banner today reads "The contents of this site were last updated on 13 December, 2011". On checking in
Wikipedia (which some would say is not the most authoritative source), I see that the various date formats in wide usage are big endian (year-month-day, going from most to least significant), little endian (day-month-year, going from least to most significant) and middle endian (starting with the month).
Little endian (e.g. 7 December 1941) is used in the majority of countries, and no commas are used; however, some German speaking countries would format the date as "7. December 1941". Middle endian is the predominant format used in the USA, and a comma is used after the day (e.g December 7, 1941). The ISO 8601 international standard uses big endian, and additionally uses leading zeros, for example, 1941-12-07. Contrary to widespread belief, the US Military now uses big endian for most of its documents, not little endian. Canada (the home of our host) appears unique in that it democratically uses all three formats. However, the use of a comma in little endian is nonstandard.
Bill