Locale warning - Please check that your locale settings are supported and installed

[Spectrum]

Hi! Certain applications, e.g. the command line tool rename, give a warning like this:

spectrum@spectrum-desktop:~/Music/music/Bands/Elend/1998 - The Umbersun$ rename 's/1998/1998 - /' *
perl: warning: Setting locale failed.
perl: warning: Please check that your locale settings:
       LANGUAGE = "en_US:en",
       LC_ALL = (unset),
       LANG = "da_DK.UTF-8"
   are supported and installed on your system.
perl: warning: Falling back to the standard locale ("C").

The settings look sane. I want my time and number formats to conform to Danish (da-DK), but I want my display language to be English.

I can't find anything out-of-place in System Settings. Does anyone know how to resolve the warning?

Thanks!

[jlittle]

...
perl: warning: Setting locale failed.
perl: warning: Please check that your locale settings:
LANGUAGE = "en_US:en",
LC_ALL = (unset),
LANG = "da_DK.UTF-8"
are supported and installed on your system.
perl: warning: Falling back to the standard locale ("C").[/code]

There's something awry in this area in Kubuntu 20.04. With my default language "British English", the second "American English", and the third "français", I get

$ echo $LANGUAGE
en_GB:en_US:fr
$ cd xyzzy
cd: aucun fichier ou dossier de ce type: xyzzy

and French in lots of places; perl has no trouble here, though.

The settings look sane. I want my time and number formats to conform to Danish (da-DK), but I want my display language to be English.

I'd have thought that would be

LANG=en_US.UTF-8
LANGUAGE=en_US
LC_NUMERIC="en_DK.UTF-8"
LC_TIME=en_DK.UTF-8

I do that, to get Danish time and number formats.

[Spectrum]

I'd have thought that would be

LANG=en_US.UTF-8
LANGUAGE=en_US
LC_NUMERIC="en_DK.UTF-8"
LC_TIME=en_DK.UTF-8

I do that, to get Danish time and number formats.

How do you recommend setting them? Via the console or via the GUI?