Block user/client/mac at certain times possible for balance 20?

I have a balance 20 at home and would like to make it unavailable to my kids when they are supposed to be in bed,any way to do that?

Please update to the latest 6.3.0 firmware and you will be able to define a schedule and tie an outbound policy rule to it:
http://www.peplink.com/support/downloads/firmware-and-user-manual-6-3/