[NTG-context] Lua os.date() localization in context

Hi all, I would like to print the day name of a date in french using my current locale. In lua I can do:

os.setlocale('fr_FR.UTF-8',all) print(os.date("%A"))

But in a cld document it doesn't work. Context complains about using "os.locale in a supposedly locale neutral enviroment" and it prints the day name in english. How can I translate the day names without hardcoding everything? Thanks in advance. Best. -- Romain Diss