LinuxQuestions.org - Configuring a Host for timebased exclusive access

Hi guys,
First a bit of background, We have a set servers we use for benchmarking some applications and do all sort of performances investigations. I am looking for a way to grant exclusive access to each of them in a time slot based manner (each dev register for a time slot and is the only one able to log into the machine during that period).The server are tipicaly
accessed thought ssh.
1 - Is there an easy way of doing that ?
2 - After a bit reading, i am thinking of having remote http server that will server a list of time slots and use pam_exec to execute a script that will querry the http server, parse the list and allow/deny the user based on that list.

I am looking for comment on my solutions

Thanks