bug reporting - The days on my lock screen are in another language

On my lock screen from Ubuntu 17.10.1,
the days are not in English but in German,
like
Monday = Montag
and
Thursday = Donnerstag.

My system standard language is English.
Is there a solution for this problem?

Make sure your current settings are correct:

1. Open Settings


2. Go to Region & Language


3. Click Manage installed languages



4. Under the Regional Formats tab, make sure English is selected, then click Apply System-Wide

   
   

   



5. You may need to log out and log in, or restart the machine, for changes to take effect

^{This is based on these instructions for an older version of Ubuntu}