Location, language and formats

[Alain Dormoy]

Hi.

I'm located in France.
I have just installed the latest version of GC over a very old one. 
The language and date formats were in French when using the old version. Now English and American date format.

When I had installed the old one (years ago) I remember having had problems ajusting the language to French. I looked into Wiki-GnuCash but didn't find the necessary info.
I think I remember there is something to change in a file but I don't remember which and where it is.

Could someone help please?
TIA
Alain

---
L'absence de virus dans ce courrier électronique a été vérifiée par le logiciel antivirus Avast.
https://www.avast.com/antivirus