Electronic Timer for 2 Answering Machines

[shirland]

I really hope someone can help me......

At the office I need one answerphone message during office hours and a different message out of hours. At the moment these are switched manually however on the odd occasions when I have to go elsewhere before going into the office, the out of hours message stays on until I can physically switch it over.

I thought of creating a standard programable timer that connects between the wall telephone socket and the two answering machines that can switch one machine off whilst switching the other on and vice versa.

I originally thought of just using electric timers as can be bought in a shop however if the power is disconnected to an answering machine then it is reset and may not work properly when switched back on without physical intervention. So my thought is that both machines remain powered up but the switching actually happens on the telephone line.

I think it should be straight forward however I have not been able to find anything that can achieve this. Any help or circuit design ideas would be very much appreciated.

Thank you.