I'd like to set up a home system where users (i.e. house kids) have a given max time of computer use per day/week/whatever, and after that time they're logged off. They should be able to log in and out as wanted as long as they still have "credit time".
Initial thoughts would be to set up some kind of remote user login based on my always-on Mac mini (or Synology NAS) that does logon/logoff accounting (some kind of Radius server? Which?)
Client computers would ideally be Linux or macOS (I'd rather avoid having to maintain a Windows computer, if I don't have to, having weaned myself out of it a while ago).
I've been looking around at how to configure things, but I'm not clear if the max session time is enforced somehow - looking for tips/tricks/experience on setting up something similar.