YOu have to set it to the time using the dial. Once you do that, use the green peg at the time you want it to go ON, and the red peg at the time you want it to go off. When it gets around to that time, it catches on a notch and the peg will either kick it on or off accordingly. That is assuming you have the one I think you do? Or if you have pegs, pushing them in will either turn it on or off, and pulling them out will do the opposite, just decide from when to when and do accordingly. You can push them in and then turn the dial to see if it clicks on or off when it hits that area to be sure which is which.