Correct "Active Until" language for Membership changes

The term Active Until in regards to membership is not clear and there seems to be a problem where it is used to mean two different dates.  

See the images attached. I canceled a membership and selected 12/31/21 as the ACTIVE UNTIL date.  When I hit CANCEL MEMBERSHIP to save the cancelation, the membership tab for that member shows ACTIVE UNTIL Jan 1, 2022. Which is it? Either it means that's the last day of membership or that's the 1st day membership is not active.  

Membership Active Until.PNG