Controlling internet access for specific devices during certain times

Hoping someone can assist with this as I am not a networking proffesional and cannot solve this issue myself.

We have the R190W which was provided by our ISP.

On this is connected 2 devices via LAN cable -  a laptop and an XBOX.

The Xbox is using port forwarding since in gaame chat does not work without it.

Also connected on an as needed basis is various mobile devices, another laptop and a PS3 on WIFI.

What i need to be able to do is disable internet access to certain devices (in particular the PS3, Xbox and 2 Cellphones) after a set time.

I was thinkin of controlling access for the wireless devices by creating a 2nd SSID and disabling this SSID at the required time.

This is set to become active at 7 and inactive at 23:00.

However this second SSID is only detectable for 30 seconds or so and then it dissapears.

Possibly I am not understanding the use of 2 SSID's at the same time correctly.

So any guidance on how to do this would be appreciated.

Secondly, if I do get that working for the Wireless, how do I get the XBOX to also not have internet access anymore at the same time but leaving the other LAN connected devices still connected?

Is there possibly another way to do both without using a 2nd SSID?