Enforcing Login-Time on NAS

I know that Login-Time can be used with Users and Groups but is there a way to use this with NAS'? For example, If I want NAS-A to allow logins only from 1700-1800 and NAS-B to allow logins only from 0900-1300. How would I be able to ensure this? I have tried this with Huntgroups, but only able to prevent/allow logins unconditionally. How do I attach the Login-Time attribute to NAS and not users or groups? -- Regards, Shivkumar