To see when a Ld expires go to the mission tab. then click the legendary missions. Under each Ld mission if you hover on the card on the legendary mission screen should show the expire date.
It uses the USA date system, Month / Day / Year
I don't think so. In France, people use the Day / Month / Year format and I actually think it makes more sense.
For definite answer, look at any thread with the last post being between 13th and 17th this month. Looks to me as DD/MM, unless they jacked up the number of the months to 17 within the last week.
Ok, it was a little confusion. I was talking about the date on the little purple square under the PLAY ! button. There the date is MM/DD/YYYY ( 07/08/2012 )
While on the missions page it clearly says DD/MM/YYYY ( 08/07/2012 ). Mixing two types of date is confusing and I think as amethal, DD/MM/YYYY makes more sense. Or even YYYY/MM/DD.