Invite Members for limited time ? 1month, 1year ...

It is VERY important for me if you could implement the possibility to invite Members for a (definable) amount of time ... they would be Member for 1 month, 1 Year ,,, and after this limited amount of time, their Membership status could be downgraded to simple Guests ... Or they could be deleted (the admin could choose with a preference...)

Thank you !