Automatically demote member

s2Member doesn’t have a feature like that, free or paid. But it’d be possible to do it…

If you have s2Member Pro, you could export all users, and edit their EOT times to what you want, and then update them in bulk. http://www.s2member.com/kb/importing-updating-users/

You could have a customization on your site that checks users’s registration times and sets the EOT time based on that, too. See:

http://www.s2member.com/codex/stable/s2member/api_functions/package-functions/#src_doc_s2member_registration_time%28%29

http://www.s2member.com/kb/roles-caps-via-php/

If you don’t know how to do this, you could post the job in a freelancers site like oDesk, Freelancer or Rent-a-Coder.

I hope that helps. 🙂