A new kind of temporary membership, depending on time intervals instead of roles

I am proposing a new kind of invite, that would allow users to stay in the guild only during the validity period of invite or a specified shorter period of time, then get kicked out unless manually marked a permanent member.

Combined with this (user-specific invite), it will enable administrators to issue bans subject to probation periods, where user-specific invites should not be affected by a ban issued prior to the creation.