Q. How does a light switch timer function?

Answer

A light timer switch is basically a timer circuit, inserted into the mains, between the power source and the light. The functioning of a light timer switch is very simple. It allows the making or breaking of a circuit, depending on the output of the timer circuit. Simply stated, the timer switch turns on or turns off the light source, depending on the inputted timer setting. So, it is a timed switch. Supposed you want the lights to turn on after six hours, then you can approach the setting feature of the timer switch and set the timer to six hours. The timer will first dim the lights and then turn it off in a minute or so, and then the timer will begin. When the timer is operational, the circuit is an open path.  As soon as the timer circuit finishes six hours, the circuit becomes shorted and the lights turn on. It must be noted that light timer switches run better with LED-based lamps.