Although there are a lot of interesting theories (“departure,” “deliverance,” and “doom,” to name a few), it doesn't really stand for anything. The term "D-Day" has been used by the U.S. military since at least 1918 as an “alliterative placeholder” for the day an operation is supposed to take place. This means that although we use it to refer to the invasion of Normandy in World War II, there's actually been a lot of D-Days.
The term was part of a larger system for keeping track of dates: D-3, for example, means three days before D-Day, and D+3 means three days after.
What does the "D" in D-Day stand for?
The "D" does not stand for "Deliverance", "Doom", "Debarkation" or similar words. In fact, it does not stand for anything. The "D" is derived from the word "Day". "D-Day" means the day on which a military operation begins. The term "D-Day" has been used for many different operations, but it is now generally only used to refer to the Allied landings in Normandy on 6 June 1944.
Why was the expression "D-Day" used?
When a military operation is being planned, its actual date and time is not always known exactly. The term "D-Day" was therefore used to mean the date on which operations would begin, whenever that was to be. The day before D-Day was known as "D-1", while the day after D-Day was "D+1", and so on. This meant that if the projected date of an operation changed, all the dates in the plan did not also need to be changed. This actually happened in the case of the Normandy Landings. D-Day in Normandy was originally intended to be on 5 June 1944, but at the last minute bad weather delayed it until the following day. The armed forces also used the expression "H-Hour" for the time during the day at which operations were to begin.
"D-Day" and "H-Hour" are general terms used for the day and hour to mark the beginning of an important event.
By far the most well-known D-Day is June 6, 1944, when the Allied invasion of German-occupied France began in WWII.
The "D" was used to mark the day that a particular operation was to begin. Each operation had a D-day and an H-hour.
Because D-Day of Operation Overlord was the largest amphibious assault in military history, it became the popular expression to refer to June 6, 1944, and was not used to mark the first day of an operation thereafter - as far as I know. It basically took on the persona that the phrase "9/11" has taken to refer to the terrorist attacks on the World Trade Center and Pentagon.
General Eisenhwer and Winston Churchill may have tried to give the "D" an actual meaning for the benefit of the press and the civilians, but previous to that, it did not stand for anything except "day" (as noted previously).
Another response
Indeed, D = Day and H = Hour, but I will elaborate a little: The invasion (or any major operation) was planned way in advance without a date being assigned for commencement. This was done for security reasons and to keep the element of surprise so that the enemy response would be minimal. For purposes of planning, you assumed the operation would start at D-Day and H-hour, with the day and time to be determined later. Then you can plan for how things will proceed, starting from Day 1 - 0 hour and start counting as in D+1 day, D+2 day, etc. Only at the last minute did anyone know what day the whole thing would actually take place.
With June 6, 1944, for example, they had to wait on the weather, amongst other things.
According to the Department of Defense Dictionary of Military and Associated Terms, D-Day means:
"D-day. The unnamed day on which a particular operation commences or is to commence."
So the D means nothing.
The initial 'D' in D-Day has had various meanings in the past, while more recently it has obtained the connotation of "Day" itself, thereby creating the phrase "Day-Day", or "Day of Days".
What does the "D" in D-Day stand for?
The "D" does not stand for "Deliverance", "Doom", "Debarkation" or similar words. In fact, it does not stand for anything. The "D" is derived from the word "Day". "D-Day" means the day on which a military operation begins. The term "D-Day" has been used for many different operations, but it is now generally only used to refer to the Allied landings in Normandy on 6 June 1944.
Why was the expression "D-Day" used?
When a military operation is being planned, its actual date and time is not always known exactly. The term "D-Day" was therefore used to mean the date on which operations would begin, whenever that was to be. The day before D-Day was known as "D-1", while the day after D-Day was "D+1", and so on. This meant that if the projected date of an operation changed, all the dates in the plan did not also need to be changed. This actually happened in the case of the Normandy Landings. D-Day in Normandy was originally intended to be on 5 June 1944, but at the last minute bad weather delayed it until the following day. The armed forces also used the expression "H-Hour" for the time during the day at which operations were to begin.
D-Day was June 6, 1944 - the Allied invasion of German-occupied France in Normandy. The code word for D-Day was Mickey Mouse.(Note: D-Day is simply a codeword, like H-Hour.)
The day of the landings
D-Day was designed to be the last push on germany. D Day was the first step in taking the war back to Hitlers Europe. At that time the Russians were pressing in the East and were taking most of the casualties in the war. Italy had been invaded by the Allies but a new front was required. Dday was the day on which (at that time) the greatest sea armada ever known was lauched against the Normandy coast. The invasion area was set into five beaches. Despite what Hollywood says it was not a solely US affair. The Americans had two of the areas, the British had two and the Canadians had one.
Delta
dangerous dragon I thought it was Dungeons and Dragons
http://www.britannica.com/dday
For Skirmish Dday you have to call. I assume it is the same for Oklahoma and other big dday games also.
how many tanks were there durind dday
About 3000 people died on Dday.
D-Day was the Allied invasion of German occupied France, on the beaches of Normandy on 6 june,1944.
August 25 1944 the DDay allied invaded Europe . It started on JUne 6,1944
Dday began the Allies' push into mainland Europe, which eventually led to the capitulation of the Third Reich in Germany
D DAY was the day the allies went to recapture france the battle following Dieppe In World War 2 in comparisson to WW1 in a sense dieppe was like the battle of the sommes and dday was like the battle of vimy ridge. Dieppe was a failure and the lessons learned lead to the success of Dday. Dday played an important part in the allies fate because the allies recaptured france who had fell to russia only 6 weeks into war. this marked the last battle in europe in ww2.
Approximately 10,000 soldiers died.The liberation of France.
The D does not stand for anything. It is simply a D.
Stalingrad in soviet union Normandy/dday in France midway and iwojima in japan
D stand for "Direct" or "Desk"