On macOS Catalina, I've installed en_GB
Firefox, my language preferences are 'Choose languages for menus messages etc' is "English (United Kingdom)", in "language for displayed pages" I've remove en_US, put en-gb
as 1st priority and en
as second and last language, and yet any HTML5 date field (for example) are not displayed in the "european" DD/MM/YYYY as they are in chromium based browsers I got (Brave for example)
Is there a way to fix that?