how to restrict user logons

["Erik Peter P. Abella" <beyonder@centinet.com>]

Hello All,

I need to be able to restrict some users from logging-on from 8am-11pm
daily (a new discounted subscription plan) and I could use some
suggestions on how to best deal with this. I intend to toggle the user
shell (/bin/false - /bin/nologin) via the crontab but am still gun-shy
on
writing a shell script.

Thanks in advance,

Erik