Need script to disable ip in address list

Hi there
is there any way to make script to disable some address in address list after period of time (20 days for example).
In address list i add users who can access network and if i want to disable some users i have to do it manualy. I need some script who will disable some user automaticly after a period of time. And after that i can then enable user/ip address for another period of time.