You want to reboot a ProxySG appliance at a specific time.
The ProxySG appliance doesn't offer a way to schedule a reboot, but if you are using Director (a Blue Coat appliance that manages ProxySG appliances), you can write a script to schedule a reboot.
ProxySG>
ProxySG>en
Enable Password: <your_enable_password>
ProxySG#
ProxySG#restart regular