When we go to Region & Language menu to change locale (language and units) of a newly installed system with GNOME, may not have the language you are looking for. For the most cases is a question of enable it on /etc/locale.gen.

For this, just edit the file /etc/locale.gen with root privileges:

$ sudo vim /etc/locale.gen

And uncomment the language that you looking for, e.g:

for

#pt_BR.UTF-8 UTF-8

remove the #, and save

pt_BR.UTF-8 UTF-8

After edit the locale file, regenerate locales with command:

sudo locale-gen

That's it! Just go to Region & Language and select your language.

referencies:

Gnome (Debian 11): How to install en*DK formats (date, numbers, units)?: https://unix.stackexchange.com/questions/679315/gnome-debian-11-how-to-install-en-dk-formats-date-numbers-units [_archive*]