Change your Hub passwords and put him on the guest account (rename it as well) Teens network or something. This can be turned off or on at your will. It dont thing this helps with wire networks but what teen would be seen with a wired network i dont think they know what a corded phone is
I was wondering the same as I have Android. I tried setting it through IP filtering and it did kind of work but did everything an hour on from the times I set it at. Weird. It's hard work to do such a simple thing.
Just to say I have switched to BT and their parental controls including setting access time limits per device are absolutely perfect: very intuitive and.... they work.
I have no expectation that Virgin will pay any attention as my understanding is that their access restrictions have never worked, certainly not in the last couple of years. But would be good if they would take a leaf out of BT's book. Many other aspects of the BT smarthub are better too.