Change calendar language

Hello, I need to change the language of the calendar format but it doesn’t work. I changed in the settings the language of the app, i translated a lot of thing but the calendar doesn’t want to change in the user app… In my calendar properties :    That work ! But in my user app : It’s always in english…   My language settings :    Thanks you for your help :) !
1 answers

EDIT : I found the error and now that work when i add a date.

But now when i want to show the date, that is in english again…