Cheap way to control exterior lighting. Only with timer you have to constantly adjust. With this clock, I have only the off time entered (in my 22:30). Is turned on whenever it gets dark. After unpacking times came the first surprise - the screen was dark. No battery to insert or update. Hm, what to do? Ah, you should plug in the device an hour and then serve. But who can read in this Mikroschift already :-). But fuktioniert. After some time the electricity, wakes the display. The guide is simply a madness. So lowercase - no chance for me to read. (Hence only 4 stars), but on the Internet you will find for download the same instructions - you can can make larger. this helps. If you understand the principle, the clock is easy to program. (Either you are a time - for on or off - or you let the field (on / 0ff) empty -: fully ok, then the clock is controlled Duch twilight For that price -.. Also, the supplier was ok. Fast delivery, well packaged. All The Best.