# What is the D in D-Day? **URL:** \ **Category:** Factual Questions\ **Created:** [July 28, 2007, 7:54pm UTC](https://boards.straightdope.com/t/what-is-the-d-in-d-day/413513 "2007-07-28T19:54:20Z")\ **Posts on this page:** 14\ **Page:** 1
**Author:** ![solkoe](https://avatars.discourse-cdn.com/v4/letter/s/919ad9/32.png) [@solkoe](https://boards.straightdope.com/u/solkoe)\ **Post date:** [July 28, 2007, 7:54pm UTC](https://boards.straightdope.com/t/what-is-the-d-in-d-day/413513/1 "2007-07-28T19:54:20Z")
My mother claims the D means _Day_ which would put the whole expression as _Day-Day_ which sounds retarded. It seems more likely that there were A, B and C days and D-Day was just the next in a sequence. What’s the dope? ---
**Author:** ![Scruloose](https://avatars.discourse-cdn.com/v4/letter/s/e68b1a/32.png) [@Scruloose](https://boards.straightdope.com/u/Scruloose)\ **Post date:** [July 28, 2007, 7:57pm UTC](https://boards.straightdope.com/t/what-is-the-d-in-d-day/413513/2 "2007-07-28T19:57:01Z")
Never underestimate the knowledge of mom. [D stands for ‘day’.](http://en.wikipedia.org/wiki/D-Day) ---
**Author:** ![Bear\_Nenno](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bear_nenno/32/3358_2.png) [@Bear\_Nenno](https://boards.straightdope.com/u/Bear_Nenno)\ **Post date:** [July 28, 2007, 7:58pm UTC](https://boards.straightdope.com/t/what-is-the-d-in-d-day/413513/3 "2007-07-28T19:58:05Z")
D-Day, H-Hour… Nothing creative. ---
**Author:** ![Stranger\_On\_A\_Train](https://avatars.discourse-cdn.com/v4/letter/s/13edae/32.png) [@Stranger\_On\_A\_Train](https://boards.straightdope.com/u/Stranger_On_A_Train)\ **Post date:** [July 28, 2007, 8:04pm UTC](https://boards.straightdope.com/t/what-is-the-d-in-d-day/413513/4 "2007-07-28T20:04:36Z")
[QUOTE=solkoe] My mother claims the D means _Day_ which would put the whole expression as _Day-Day_ which sounds retarded. It seems more likely that there were A, B and C days and D-Day was just the next in a sequence. What’s the dope? [/QUOTE] “D-Day” and “H-Hour” are military designations for the time at which an operation is due to commence. The “D” and “H” don’t actually stand for anything, other than an indication that it’s a particular or special time. Thee term “D-Day” is popularly associated with the Normandy Invasion and Operation Overlord, but the term is used generically in other major operational events as well. There is a famous “A-Day” in WWII, but it actually occured after the invasion of Normandy, and in the Pacific theatre, with the famous (or infamous) Invasion of Leyte, starting 17 October 1944, as part of MacArthur’s campaign to retake the Philippines and get some spectacular wading ashore footage in the bargin. (The famous shot at Palo Beach had to be recreated several times until it met MacArthur’s satisfaction.) There are other alphabet days designating various types of activites, though no specific standard, and for most the preceding letter bears little resemblence to the activity thereby described. Stranger ---
**Author:** ![Speaker\_for\_the\_Dead](https://avatars.discourse-cdn.com/v4/letter/s/c77e96/32.png) [@Speaker\_for\_the\_Dead](https://boards.straightdope.com/u/Speaker_for_the_Dead)\ **Post date:** [July 28, 2007, 8:08pm UTC](https://boards.straightdope.com/t/what-is-the-d-in-d-day/413513/5 "2007-07-28T20:08:19Z")
The use of “D-Day” and “H-Hour” allows you to set goals and plan without knowing the exact date of your project. You can say, “at H plus 2 hours, we want to have secured the beach-head.” It’s the exact same as the shuttle countdown, with “T minus 10 seconds.” The shuttle launches at T-Time. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [July 28, 2007, 8:49pm UTC](https://boards.straightdope.com/t/what-is-the-d-in-d-day/413513/6 "2007-07-28T20:49:32Z")
[QUOTE=Speaker for the Dead] The shuttle launches at T-Time. [/QUOTE] That’s four O’clock isn’t it? ---
**Author:** ![I\_m\_Ron\_Burgundy](https://avatars.discourse-cdn.com/v4/letter/i/9fc29f/32.png) [@I\_m\_Ron\_Burgundy](https://boards.straightdope.com/u/I_m_Ron_Burgundy)\ **Post date:** [July 28, 2007, 9:10pm UTC](https://boards.straightdope.com/t/what-is-the-d-in-d-day/413513/7 "2007-07-28T21:10:33Z")
In French it’s J-Jour ---
**Author:** ![Scruloose](https://avatars.discourse-cdn.com/v4/letter/s/e68b1a/32.png) [@Scruloose](https://boards.straightdope.com/u/Scruloose)\ **Post date:** [July 28, 2007, 9:29pm UTC](https://boards.straightdope.com/t/what-is-the-d-in-d-day/413513/8 "2007-07-28T21:29:33Z")
> [@Speaker for the Dead](#): > > The shuttle launches at T-Time. It seems that lately, they’ve been launching at [Miller time.](http://abc.net.au/news/stories/2007/07/28/1990776.htm?section=world) ::rimshot:: ---
**Author:** ![some\_white\_dude](https://avatars.discourse-cdn.com/v4/letter/s/b487fb/32.png) [@some\_white\_dude](https://boards.straightdope.com/u/some_white_dude)\ **Post date:** [July 29, 2007, 2:07am UTC](https://boards.straightdope.com/t/what-is-the-d-in-d-day/413513/9 "2007-07-29T02:07:30Z")
[QUOTE=Scruloose] It seems that lately, they’ve been launching at [Miller time.](http://abc.net.au/news/stories/2007/07/28/1990776.htm?section=world) ::rimshot:: [/QUOTE] _applause_ Would I be correct in assuming that this generic method serves security purposes as well? After all, you wouldn’t want the other side to know what day you intend to strike in case they intercepted communications. ---
**Author:** ![Paul\_in\_Qatar](https://avatars.discourse-cdn.com/v4/letter/p/ccd318/32.png) [@Paul\_in\_Qatar](https://boards.straightdope.com/u/Paul_in_Qatar)\ **Post date:** [July 29, 2007, 2:28am UTC](https://boards.straightdope.com/t/what-is-the-d-in-d-day/413513/10 "2007-07-29T02:28:34Z")
As said, nothing much. The first of use of the term was in a US Army document from WWI. Also as stated it is J-Jour in French. M-Day is the day of mobilization. Other days have their own letters. Oddly the use of D-Day is less so since 6 June 1944 has preempted the term. ---
**Author:** ![detop](https://avatars.discourse-cdn.com/v4/letter/d/bcef8e/32.png) [@detop](https://boards.straightdope.com/u/detop)\ **Post date:** [July 29, 2007, 2:35am UTC](https://boards.straightdope.com/t/what-is-the-d-in-d-day/413513/11 "2007-07-29T02:35:08Z")
[QUOTE=I’m Ron Burgundy?] In French it’s J-Jour [/QUOTE] Actually, it is Jour-J. And for the invasion of Okinawa, it was L-Day. ---
**Author:** ![Speaker\_for\_the\_Dead](https://avatars.discourse-cdn.com/v4/letter/s/c77e96/32.png) [@Speaker\_for\_the\_Dead](https://boards.straightdope.com/u/Speaker_for_the_Dead)\ **Post date:** [July 29, 2007, 5:58am UTC](https://boards.straightdope.com/t/what-is-the-d-in-d-day/413513/12 "2007-07-29T05:58:41Z")
[QUOTE=Paul in Saudi] As said, nothing much. The first of use of the term was in a US Army document from WWI. Also as stated it is J-Jour in French. M-Day is the day of mobilization. Other days have their own letters. Oddly the use of D-Day is less so since 6 June 1944 has preempted the term. [/QUOTE] I can see why. It’s really strange to hear 1943 footage (after the action, of course) referring to the invasion of Tarawa on “D-Day,” if you’re not used to it. ---
**Author:** ![Paul\_in\_Qatar](https://avatars.discourse-cdn.com/v4/letter/p/ccd318/32.png) [@Paul\_in\_Qatar](https://boards.straightdope.com/u/Paul_in_Qatar)\ **Post date:** [July 29, 2007, 8:58am UTC](https://boards.straightdope.com/t/what-is-the-d-in-d-day/413513/13 "2007-07-29T08:58:30Z")
“Love Day” for Operation Iceburg Easter Sunday, 1 April 1945. “Love” was then the radio phonetic used by the military. Oddly no documents seemed to call D-Day “Dog Day.” Go figure. X Day was the planned day for the invasion of Japan. ---
**Author:** ![twickster](https://avatars.discourse-cdn.com/v4/letter/t/ec9cab/32.png) [@twickster](https://boards.straightdope.com/u/twickster)\ **Post date:** [July 29, 2007, 11:49am UTC](https://boards.straightdope.com/t/what-is-the-d-in-d-day/413513/14 "2007-07-29T11:49:09Z")
[QUOTE=Mangetout] That’s four O’clock isn’t it? [/QUOTE] Only if the golf course is ridiculously overbooked that day.