I built a day/night controller so that the baby chickens can have something resembling a diurnal cycle. This wasn’t strictly necessary, people have raised chickens with nothing more than a light bulb on a cord for decades and they turn out fine. I can’t resist an opportunity to build a nifty gizmo however, so I put together the Chicken Controller.
It has a double-throw time switch, which basically means that it can switch automatically between the red heat lamp and the white heat lamp to simulate night and day in the chicks’ little Rubbermaid universe. So far it seems to be working out pretty well.