Controls are time consuming to setup. Even though the Home Depot timer is cheap, I still wouldn't carry current in the internal relay with anything for non-residential use. With the right setup, it can be made industrial duty.
Check out the Eaton BA breaker or equivalent needed for your particular panel. You need one per circuit. Current carrying circuit don't get rewired. Every reconfiguration gets done on the 24v side.
The control input needs 3 or 4 conductor CL2 and a basic HVAC 24v transformer. Energize one leg for on, another for off. So you just juggle the 24v with a simple SPDT relay powered from the wall switch. You only need one timer unless you have to have different parts of the lot on different schedule.