Expiration date to "Role"

When expired have it set to which "Role" it should be changed to.
Say a client buy access to a mastermind and/or a program for 4-8 weeks and I want to track it via a tag that expires 4-8+ weeks as agreed upon. That way, the client will lose the access the tag gave after that time period and turn back to a "normal"/free member of the community.