In Essay d'une parfaite grammaire de la langue françoise, the Jesuit Laurent Chiflet (1598–1658) writes:

Ie vous iray voir , aprés trois jours , aprés quatorze jours , aprés un mois. Dites, je vous iray voir dans trois jours , dans quinze jours , dans un mois : ou, d'icy à un mois. Les Flamands pour exprimer deux ſémaines , diſent quatorze jours : mais les François diſent quinze jours. (p. 191)

This is reminiscent of British vs. American usage around fortnight. Americans simply say two weeks; for fortnightly, they use biweekly or every two weeks.

Does this distinction between the Belgians saying fourteen days for two weeks and the French preferring fifteen days still pertain? Do Belgians still use quatorze jours where the French would use quinze jours for a period of two weeks?

  • 1
    "biweekly" is ambiguous. It means either "twice a week" or "once every two weeks". But I agree that Americans don't understand "fortnight".
    – alephzero
    Feb 3, 2021 at 20:15
  • 2
    @alephzero no ambiguity to me: semi-weekly is twice a week (as semi-annually is twice a year, etc); biweekly is once every two weeks (as biannually is once every two years). (Whether or not dictionaries agree here is another discussion...) Feb 3, 2021 at 23:43
  • 1
    I once had two part-time jobs for the same employer. One was paid every fortnight ("biweekly," every other Friday), the other twice a month ("semi-monthly," on the 15th and the last day of each month). Gawd it made budgeting impossible.
    – verbose
    Feb 3, 2021 at 23:51
  • 1
    I was raised in the French school system, but have lived in English speaking countries for over thirty years. Just last week I was mentally solving a math problem to check my son's homework. I got the answer wrong because I mentally used 15 for "two weeks" instead of the correct 14. So I'd say it's pretty deeply ingrained! Disappointing for a country that is usually strong in math.
    – PatrickT
    Feb 4, 2021 at 5:06
  • 1
    @D.BenKnoble "Biannual" is twice a year; "Biennial" means every two years. Feb 4, 2021 at 11:33

2 Answers 2


I cannot prove it with hard facts or numerical data, but I am Belgian, and quinze jours is the dominant phrase here as well for "two weeks", and not quatorze jours. If there was a regional difference in the past, it seems it has disappeared nowadays, and the usage in Belgium is the same as in France.

Some examples taken from Belgian websites:

Le Soir: Si, dans quinze jours ou trois semaines, on constate que l’épidémie retrouve sa courbe ascendante avec toutes ces souches mutantes, on peut imaginer qu’il faudra avancer l’heure du couvre-feu.

RTL info - Belgique: Leur voyage, prévu dans quinze jours, est annulé.

EDIT: see also the very good comment from @freddieknets: this reply above applies to native French speakers from Belgium. The original article quoted by OP refers to "Flamands", ie, to Flemish speakers using French as a 2nd language and transposing Flemish phrasings to French. In some extent, there has been an influence of Dutch/Flemish on Belgian French (ex: "une fois", "savoir/pouvoir" used indifferently), but that does not seem to be the case for this phrase.

  • 1
    "the usage in Belgium is the same as in France" - I would like to point out that during my time in France (since I was born), I have never seen anyone use 15 days as a substitute for 2 weeks. There are situations when people said "see you in 15 days" when they meant like the Wednesday of 2 weeks later (since today is Wednesday and the day isn't over yet), but that's the only case I can remember.
    – Clockwork
    Feb 4, 2021 at 17:07
  • 1
    @Clockwork , "I have never seen anyone use 15 days as a substitute for 2 weeks" ??? I am sorry but the truth is that: it is a fifty-fifty usage "see you in 15 days" or "see you in 2 weeks" are said indifferently by all people in France with maybe more usage of the "15 days" variant... Feb 4, 2021 at 17:39
  • 1
    But does quinze jours actually mean two weeks or does it mean what it says: "two weeks and one day"? I am far from a native french speaker, but I have lived in France a few years and never noticed this. Are you saying that when people told me en quinze jours they actually meant in two weeks instead?
    – terdon
    Feb 4, 2021 at 18:06
  • 1
    @terdon Yes indeed. If today is Monday and a French person says on se voit en quinze jours he means you'll meet again in two weeks, on Monday. Feb 4, 2021 at 20:34
  • 2
    @Clockwork It must be a regional thing (in France), since I'd say quite the opposite: I've almost never heard "dans 15 jours" to mean exactly 15 days. For example, if there's someone normally visiting at the weekend (e.g. Friday to Sunday), and if they say "À dans 15 jours" when they leave on Sunday, I'd expect them on the Friday night (13 days later) as usual, and that would be natural. If I actually meant 15 days, I'd specify "À dans exactement 15 jours". Also, I'd take "on se voit tous les 15 jours" ambiguously and meaning "every two weeks" by default.
    – Bruno
    Feb 5, 2021 at 12:02

I want to add to Greg's answer, from my perspective (somebody from Flanders, the northern part of Belgium). We don't speak French, but a regional variant of Dutch (Flemish). And we say "over veertien dagen" which would indeed translate to quatorze jours.

Why is this relevant? Because OP's quote says:

Les Flamands pour exprimer deux ſémaines , diſent quatorze jours

Les Flamands, that's us, the Northern Belgians. It should be noted that language is, and has always been, a sensitive issue in Belgium. Historically the only official language in Belgium was French (now it has three official languages), even though the people in the Flemish region have been speaking some form of Dutch since medieval ages. For a long time, this was just considered the language of the common folk, while French would be the choice of communication among the higher classes (even if their native tongue would still be Flemish). This only refers to the Northern parts of Belgium, in the South everybody has always been speaking French.

Hence, with the quote explicitly referencing les Flamands, I would assume that the difference that Laurent Chiflet observed in the 16th Century originated in Flemish people translating their tongue to French too literally, introducing a Germanism style error.

  • 1
    @verbose The official languages in Belgium are Dutch, French and German. In Flanders, the only official language is Dutch. However, there are a number of [municipalities with language facilities ](en.wikipedia.org/wiki/Municipalities_with_language_facilities) - a politically highly charged topic ...
    – Tsundoku
    Feb 4, 2021 at 11:40
  • 1
    @verbose German. It's spoken by around 100.000 people only (less than a percent of the population). Because of them I was forced to learn German at high school :-D Feb 4, 2021 at 11:41
  • 2
    Note that in the South of Belgium, there was also a language difference between the French speaking higher class and the remaining of people speaking Picard or Walloon. Of course, the proximity of these languages with French made bilinguism and the switch to "standard" French natural.
    – jlliagre
    Feb 4, 2021 at 13:07
  • 2
    This is in my opinion the correct answer. It seems likely that the distinction isn't being made between French and Belgian French, but rather French and Dutch. It is not uncommon for texts to refer to other languages through transliterations.
    – jMdA
    Feb 4, 2021 at 23:30
  • 1
    @freddieknets: your comment is very relevant, I'll edit my answer to clarify. I have read the full chapter the quote is taken from, and note that "Flamands" is used from the perpective of the XVIIth century geopolotical situation: the author refers mainly to "Flamands", then talks about "Flamands et Brabançons", and then even talks about influence of Walloon all the same... I wonder if in that period, "Flamands" was not more limited to the historic county of "Flandres" (ie, approx. today's West-Vlaanderen, Oost-Vlaanderen and the French déprtement du Nord)
    – Greg
    Feb 5, 2021 at 7:50

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Not the answer you're looking for? Browse other questions tagged or ask your own question.