Undestand every one of the available methods of setting your lights on a timer and choose the one which best suits your style and needs. The things they basically do is let you set an on / off time with your outdoor lighting system.
The standard outdoor outlet timer is just a unit that permits you to place pegs into slots which designate which times you desire to have the lights turn on and off. Some of the more sophisticated units allow you to actually program custom times for any seven day week, however these kind of timers are often used with lamps and xmas lights.
If you want to have an advanced outdoor light timer system then we suggest using a photocell timer unit. This technology is actually able to sense changes inside the levels of sunlight directed at it and adjusts the light on and off as it is needed based on sunlight levels. Some of them even possess the ability to change the intensity of the light down and up saving you even more money when in operation.