"D-Day" was the day of the beginning of the Allied inavasion of Europe for the purpose of driving out the Nazis. It was the largest amphibious assault ever. While the overwhelming scope of that operation has given the term "D-Day" that special significance, it originally was, and still is, rather mundane military terminology for a target day in planning a campaign, in the same way the term "H-Hour" is sometimes used. The terminology makes it possible to do the planning without reference to actual calendar dates, partly for reasons of operational security, and partly because that daate might not be finally chosen until late in the process. So in the scheduling of events, it would look like a countdown: D-Day-minus-10, D-Day-minus-9, and so on as preparations are made, up until the day the operation began, D-Day, followed by D-Day-plus-1, D-Day-plus-2, which would deal in goals for the operation and the ongoing support.
dday means doomsday
In Normandy, France. All over the beaches
dday what a final attack of the axis powers on the allies no mate... dday was he day that the retard from America predicted the end of the world on 21st may 2011.. and failed. haha to all the believers.. if it was me saying we were gona die tomorrow.. you wouldn't believe me would you. but yeah dday is now 21st october 2011... which ain't gona happen either. so yeahh that's all there is. hope this helps :)
Normandy
in Normandy, France
yes that's why all the other beacheads were an easy victory for the other countries
About 3000 people died on Dday.
6 June 1944
For Skirmish Dday you have to call. I assume it is the same for Oklahoma and other big dday games also.
http://www.britannica.com/dday
Dday
jaankaree, aank-dday