How does a cuckoo clock work? The heart of the clock is the movement within the clock. The key that moves it are the weights located at the bottom of the clocks. If you look at clock pictures, you will see the weights hanging below each of the clocks, most often in the shape of pinecones. The weights drop over either a one-day or eight-day period and provide the clock’s functions. Some clocks come with two some with three weights.