Why Is It Called D-Day?

November 21, 2019  - by 
D-Day soldiers on a ship

On June 6, 1944, Allied forces invaded German-occupied beaches of Normandy, France. This significant day in history became commonly known as “D-Day,” though the actual meaning of the nickname isn’t as well understood.

Naming Theories

There are a few conjectures as to what the “D” stands for. Some have said it is an abbreviation for “departure” or “decision.” Others claim that it stands for “doomsday.” However, according to the United States military, the origin of the popular nickname has more to do with their terminology.

The Meaning of “D-Day”

The phrase “D-Day” was used by the Army to designate a specific starting date for field operations. Other phrases, like “D+2” would have referred to two days after the initial “D-Day.” This designation suggests that the letter “D” doesn’t stand for anything in particular outside of “Day” and that it served only as a point of reference.

Ships landing on D-Day

A similar term was used to refer to the designated hour on D-Day when the attack would begin. It was called “H-Hour” and “H-4” would have referred to four hours before the planned invasion.

Using this kind of shorthand military terminology dates back to recorded field orders in World War I, and an equivalent can be found in many countries. For example, you may have heard of “Zero Hour,” which is used by the British in conjunction with “Z-Day.” The term would be “Dan D” in Slovakia and “Lá L” in Ireland.

Do you have family who served in the military? Consider asking them about different military terms and stories and recording their responses in FamilySearch Memories. You might be surprised by what you discover!

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  1. In the 82nd Airborne we called it Drop Dead or Down day, in a joking way. I didn’t see any combat time, but the company I was in was surely ready for anything that may come along. The wars ended just before I went into the Service.

  2. Very interesting and thank you for your interest frequently I speak before group of students from time to time and have been impressed with how little I know about World War II as an example I would incorporate family gatherings to raise money to to fund the war if you recall the band program then I would talk to them about victory Gardens saving twine saving scrap metal saving aluminum all for the efforts in the war.

    Everybody during World War II was patriotic every child every teenager every young adult every adult everybody in the family every family was very patriotic and I hope to help doing whatever they were able to do to help with this war and today unfortunately these young people I have no idea but in any event I felt talking about what happened during the war to help in the war was just as important as me telling them what I did a board and aircraft carrier in the Pacific well thank you for all that you’re doing and just for an interesting note you might Be interested in knowing that I manage my church is Cemetery which is 148 years old and eventually the cemetery will be a great site for genealogist to go to the pick up information on their family were saving everything we can find on the Internet for every family we have about 1000 people buried it’s a small sanitary but when I took over we had no birthdates today 98% of those people we do have birthdate and a lot of other information to just thought you’d

    1. That’s a wonderful thing you did. My great grandfather is buried in a little cemetery like that, with no marker. His military marker is placed beside my great grandmother in a different county in Missouri.

  3. Perhaps you can answer a question for me. In the memories section of Family Search, I posted a picture of my Father at his battle station during WWII on a Liberty Ship on his PID. There was in the background a picture of the gun he operated. The picture was removed by Family Search because of “content”. I’m wondering how you can post pictures with many, many more guns visible than the single one that was in my Dad’s picture. Seems a bit hypocritical to me. If one gun is bad, many should be worse.

    1. I loved the article. I am only 10 years old but I love history. For 5 years I have been learning about more history. But when I was 5, I heard about Pearl Harbor and watched a documentary about it and that kick started my love for history and WWll.