Plz help where is the mistake?

ouaip c'est moyen, il faut inverser le jours et le mois (et ça marche aussi avec le caractère d'échappement) You were right @horst : the checker want to make date great again (month/day/year)

Looks pretty correct. I think the only flaw in your code might be inside the Print-Statement (line 19). 1. I don't know if the new-line character (\n) is accepted by the checker. It is definitely worth a try to use two independent Println-Statements instead. 2. In the english version, the date format was a bit tricky. They wanted us to print out MM/DD//YYYY and the way to find out about this was the given example "2/15/1988", from which our standard continental European brains could deduce that there is no such thing as a 15th Month in the year... However, in your case the example is given in the "correct" format, which makes it close to impossible to work this out on your own. So my suggestion: try both of the changes - not at once, of course - and one of them should be the problem.