Motion Light/ switched light

Well im trying to help out a neighbor and he has hit me with a pretty tricky situation.

He currently has an out door light on a timer. Its set to come on at 8pm and turn off at 10pm. He wants to install a motion detected flood light that will still turn on with the timer every night but once it turns off at 10pm he wants it to come on when it senses motion.

Is this possible? Ive been trying to think of options but I only see having 2 seperate lights as the solution.

Anyone have any ideas?

Wire the two switches in parallel.

^ is correct. You will have to rewire how the sensor is hooked to the flood. Once you look at the internal wiring you will see that it is a simple inline switch. Wire the timer and the sensor in parallel so that the timer can supply power and when off the sensor also has power to supply. Make sure that you use a meter to check your wiring with the timer on and the sensor on simultaneously with no bulb in the socket.