cron and logins

[Bob B. Funchess]

I want to set up a system on our 4D/20 where certain users can only login
at certain times, such as non-prime hours.  The only way I can think of to
do this is to have cron swap /etc/passwd in and out at these times, and
frankly this frightens me a little :).  Does anyone have such a setup?
Will you share your secrets?  You can mail me direct at the address below...


                             < Bob  S090726 at UMRVMA.UMR.EDU  Funchess >