What I've done; during install, I chose English as a language, and Belgium as location.
However at login screen I noticed that the date was displayed in German (I don't understand that language, so I never chose that).
I went in System Settings, Regional Settings, and only modified things there.
I wanted to have things set up in English, with € as currency. That did not work, so I gave up and wanted to configure everything in en_GB since that should work, but things seem worse than ever