In French, we use "D-Day" (Jour J) for any major coming event, a wedding for instance.

But when I look for "D-Day", I mostly find results on the Normandy landings, or military usage in general.

The Cambridge dictionary states "D-Day" can be used for a day when something important will happen, and Collins Dictionary seems to say that this usage is valid only in British English.

How common is it in English to use "D-Day" as a reference to an important coming day? Can I say:

The preparations will be complete for the D-Day.


The elections are coming soon. We are ready to vote on the D-Day.

  • 7
    As a note, the article "the" is not used for "D-Day" (or the less common "H-Hour"). Oct 25 '18 at 15:52
  • 1
    Speculatively, so not an answer: Whilst it does not seem etymologically correct, there is a common interpretation in the UK with it standing for Doomsday. This important event in English history. So, perhaps that association means British English use of D-Day has a connotation not present in American English, one that means the day has great significance without implying it is military.
    – Keith
    Oct 26 '18 at 0:25

This answer piggy-backs on the comments under Nathan Tuggy's answer.

Everyone knows there could be possible negative consequences for voting poorly on Election Day; however, D-Day would be the wrong analogy to use. Assuming the elections are largely peaceful and uneventful, the worst a voter could encounter on Election Day is a long line.

That said, the analogy might be fitting if one poll worker was talking to another. That worker might say, "The elections are coming soon. We will be ready to set up on D-Day." Considering how much equipment needs to be set up and ready to go at such an early hour, that analogy would be entirely fitting and readily understood in context.

I also don't agree that this is "only a valid usage in British English." As an American, I've seen it used from time to time, although it can be difficult to find examples because so many of the hits will be related to the World War II invasion. However, here is one example, taken from a 2015 Florida business news article:

Both companies [Uber and Lyft] are fighting the taxi medallion-owning establishment, cabbies protesting in France, a backlash from New York's Mayor DeBlasio, and now half of South Florida. Broward County is pushing them out, a driver was arrested in Key West for driving an 'unlicensed vehicle for hire,' where there isn't even Uber service yet, and now as they plan their next moves toward full legalization, Uber is ensconcing itself down here pretty much permanently, ready for D-Day.

And from CIO, in an article about promotic events:

Once you’ve planned an event and decided on the dates and the venue, you need to market it. There are conventional methods for building hype and awareness around events. Use of social media is one of them. Building a steady tempo on social media as D Day approaches is a strategy most commonly used by many brands to create awareness.

Moreover, the American Heritage Dictionary defines D-Day generically as:

  1. The unnamed day on which an operation or offensive is to be launched.

That said, having scoured through some news articles, it does seem more commonly-used in BrE publications. But that wouldn't "invalidate" usage on American soil.

One other footnote: We don't typically use the definite article with D-Day. So, when preparing for a wedding or other big event, you would use it like this:

Imagine you have a house party. As D-day approaches, here's what you're ticking off your mental checklist.


Imagine you have a house party. As the D-day approaches, here's what you're ticking off your mental checklist.

  • 1
    Interesting last footnote. The consensus seems to be that "D-Day" would be an unusual analogy used for an important day that entails some strong negativity. Thanks for the answer! Oct 25 '18 at 11:06
  • 3
    @JulienLopez "negativity" might be the wrong word. Definitely important, first and foremost, but instead of "negativity", I would consider stress, or a tipping point (potential for things to go either way) to be factors.
    – Baldrickk
    Oct 25 '18 at 13:03
  • 4
    @Baldrickk - I would add to that list of factors intense planning or preparation beforehand.
    – J.R.
    Oct 25 '18 at 14:00
  • 1
    @JR oh definitely. In fact, I think it goes hand in hand with the importance. I think that was what I was trying to say with the "tipping point" comment - with lots to plan, there is also a lot that can go wrong.
    – Baldrickk
    Oct 25 '18 at 15:20

In America, most people think of the historical event first, and tend to work backward from there by analogy to other uses. This is at least partly because American troops made the landings at Omaha Beach, the most heavily-opposed and bloody of the landings, and the losses sustained there left a deep impression on the American collective consciousness. (The troops landing on other beaches were mostly British and American and some Canadians, with Australians, Free French, and New Zealanders mostly in naval and air support roles.)

Typically, then, "D-Day" carries connotations of anxious preparations for an event that probably won't be enjoyable. Using it for a wedding sounds strange, although one could take advantage of that contrast for some slightly dark humor from the over-stressed planners. Using it to talk about voting in elections doesn't make much sense at all, as there's no direct repercussions for voting poorly.

The usage is perhaps also the same in other English-speaking countries, for similar reasons.

  • 5
    "there's no direct repercussions for voting poorly." I would disagree on that. ;-) Thank you very much for your answer! Oct 25 '18 at 8:38
  • 3
    Curious as to the American centricity of your answer? Was it deliberate, for some purpose that I've missed, or simply because that's your viewpoint (which would be fine, just trying to figure out the context). If the latter, then FWIW your observations IMO are equally appropriate in the UK - that "D-Day" has come to generally mean the D-Day Landings is not specific to the Omaha Beach portion of that operation, nor to the compatriots of specifically the American contributors. To be clear though your answer is spot on. Oct 25 '18 at 10:13
  • 3
    I'm not sure I'd agree with "won't be enjoyable". However it certainly implies a major, momentous event.
    – Graham
    Oct 25 '18 at 12:28
  • 1
    @LightnessRacesinOrbit I don't find it that hard to believe that D-day would stand out more in the American psyche. We weren't in the war for as long as the UK, and didn't suffer large scale attacks on our mainland. I'm not saying it wasn't a significant event for the Brits, but you had a lot of other very bad days that also left their mark. Oct 25 '18 at 12:44
  • 1
    @pboss3010 Right but what I mean is this answer only really talks about that American viewpoint and I can't figure out why Oct 25 '18 at 12:54

Since no one else mentioned it, I feel like it would be helpful to add, that the term D-Day is simply a variable for an as-of-yet unspecified day. It is commonly used in military planning to reference time based on an unknown starting point. This is used in concert with similar terms like H-Hour, M-Month, etc.

With respect to the Normandy landings, the news media took the plan term D-Day and ran with it. It was never intended to specifically reference a single event in time, but the term became inextricably linked to the Normandy landings.

  • It might' be worth providing evidence that as well as its use in Operation Overlord, other military Operations such as Torch and Husky also used the term D-Day.
    – Sarriesfan
    Oct 25 '18 at 20:37

"...and Collins Dictionary seems to say that this usage is valid only in British English."

As an American, I would have to agree. I think that if we use it, it refers not just to an important event, but one that is likely going to be disastrous or perhaps chaotic(?). The only examples I can find on Google are political or about investments, such as,

“The House Is Already Lost”: As the Midterms Approach, G.O.P. [political party] Insiders Prepare for an Electoral D-Day

  • Thank you for your answer! So you would say that most U.S. speakers would not use "D-Day" that way, correct? Oct 25 '18 at 11:09
  • 2
    @JulienL - Your questions are difficult to answer because you keep asking questions like, "Would it be common?" and statements like, "It would not be used." Take any big event that requires a lot of planning – it could be a class reunion, or the grand opening of a new restaurant. Most speakers would probably just use a more generic phrase, such as "the big day," as in: Only one more week until the big day. Occasionally, though, you might see a reference to "D-Day" instead. Just because it's not "commonly used" doesn't mean that it's never used, or that it wouldn't be readily understood.
    – J.R.
    Oct 25 '18 at 13:59
  • 1
    @J.R. I don't understand your comment. If my question was easy to answer, I wouldn't have bothered to ask it here. My question is about how commonly used this expression is. Oct 25 '18 at 15:26
  • 1
    @JulienL - I don't think the expression commonly used – but that's not quite the same thing as "most speakers would not use it", nor is it quite the same thing as "an unusual analogy", nor would that make the dictionary's definition "obsolete".
    – J.R.
    Oct 25 '18 at 16:05
  • 1
    @J.R. I think that's a good way to put it. I'm Canadian, I rarely see it used; but when I do, the meaning is understood. I personally am not likely to use it, and neither are most; but most people seem to understand it in context.
    – JMac
    Oct 25 '18 at 17:06

As an American English speaker, I have heard D-day used in this way. Most of what I see in the other answers I would agree with, but I would add a key detail. Every usage of D-Day has been an irrevocable event. There is no hitting a D-Day, deciding it didn't go well, try to reel in your efforts, and aim for a second D-Day. When you hit a D-Day, it is a reckoning. One usually feels some nerves as D-Day approaches.

For the most part, you would not say "The elections are coming soon. We are ready to vote on the D-Day," but you might use that terminology for a critical election. I could see someone using it with respect to the recent 2016 presidential election, given how it was seen by many as either the day where sanity prevailed, or madness ensued.


As another British English native speaker, "D-Day" does get used occasionally for important events that have to be planned meticulously, and where failures of organisation will present major problems.

If the plan needs actions to be timetabled carefully over several days before and after the event, hour-by-hour during it, with spare time carefully inserted, and arrangements made for the failure of events, then you can use D-Day and H-Hour without it seeming inappropriate.

With such requirements, the connotations of the phrase, implying a special effort, with unusual risks and a strong need for sticking to the plan, become helpful. Without those requirements, use of D-Day and H-Hour will seem over-dramatic and detract from the plan's credibility.


Speaking purely as a native British English speaker, and, I must admit anecdotally, I have never heard D-Day used to refer to anything other than the event itself. Collins must be getting it from somewhere, but I can tell you that the usage is not common currency in the UK.

Granted, if you'd used it in this way, someone would probably understand fairly well what you meant, but it's not something that I know of that we'd actively say (unless talking about the event itself or its anniversary.)

  • Thank you! This is the kind of answer I was hoping for. Would you say that the definitions in the dictionaries I linked to are incorrect then? Or obsolete today? Oct 25 '18 at 11:17
  • 1
    I wouldn't say they are incorrect or obsolete, just that they are not in common colloquial use here. Largely, I think this is social, as D-Day is a massive part of British cultural history (like a lot of World War 2,) so for us, when we use the phrase, we think first and immediately of the event. It may crop up in business speech (which has a habit of repurposing old words for new situations) or other niche situations, but as a common day-to-day phrase, it would be unlikely to be used in this context.
    – Wenlocke
    Oct 25 '18 at 11:35
  • 3
    In British military planning documents of the era (and later) one sees dates and times denoted by the first letter of the time period or point, thus D-day, H-hour, D+1, H-2, etc. For us there were lots of D-days. I do not know if the terminology was widely used by American forces. Oct 25 '18 at 12:06
  • 1
    US forces used D-day and H-hour when planning during World War One. Oct 25 '18 at 12:13
  • Did not know that, interesting information (I assume this is also the origin of T-<x> in rocketry countdowns.) I suspect the disconnect is there because while the military may have had numerous D-Days, our cultural narrative, there's only one D-Day that was actually publically named so and made it into popular culture.
    – Wenlocke
    Oct 25 '18 at 13:21

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .