I do have the Time Range set to turn off the APs we do not want broadcasting but I must keep the Guest network up and running all of the time.
Unfortunately I am not allowed to set any authentication on the Guest network, this is why I'm looking at reducing the RF to limit how far it extends out into the neighborhood.
There are two ways that I use to determine that our neighbors are using the Guest network or not. Airwave does a good job of triangulating if the client is outside the building and If there are no conferences going on, there shouldn't be more than 10 people accessing the Guest network per school.