Le jour J is a French expression that refers to June 6, 1944, the Day that the Allies stormed Normandy Beach in France during the second World War. In English we usually refer to this as D-day. Le jour J is also used by the military to specify when a military operation will take place. The letter “J” simply refers to the word jour (day). Another way to say to say le jour J is le grand jour.
In daily life le jour J is used when referencing an important day, usually something that required a lot waiting. In English we typically refer to this as the big day. Both in French and in English le jour j and the big day is supposed to be something that is relatively positive and exciting. In English, D-Day is sometimes used when talking about a day of impending doom such as having to give a big speech that you aren’t looking forward to.
Let’s look at some examples of le jour J used in context.
J’espère te voir le jour J – I hope to see you on the big day
Le jour J est enfin arrivé – The big day has finally arrived
J’ai hâte de te voir le jour J – I’m looking forward to seeing you on the special day
On s’entraîne pour le jour J – We’re training for the big day
Le jour J is a simple expression that you will hear from time to time. Once you see it used a few times you shouldn’t have much difficulty adapting it into conversation. For other vocabulary and expressions head on over to the French vocabulary page.