Two power sources, one 3-way switch?
I personally think you are going way overboard with what you propose. These days all your newer stuff charges with 5V on USB Type A connectors. The charge controllers inside your phone / tablet / GPS / whatever else are smart and will service the internal battery in the proper way. So there should be no need for this two hours per day timed behavior. 

So if you have five devices to charge get one of these. For ten devices get two.