Dusk to dawn lights are an energy-efficient solution to a common problem in any home — people forget to turn off lights. They use photocells that detect light, and then turn on only when the sun sets and turn off again at sunrise. The system conserves energy so homeowners never have to worry about wasting money on expensive electricity bills.
These lamps run by themselves, automatically turning off and on at sunrise and sunset. Since these times can change with the seasons, using a timer might take a lot of effort. A small, low-cost component is all it needs to be energy efficient.