Aart, I do have a unique situation in my coop and maybe you can help me. I am keeping my coop (12 x 10) closed all the time (just a hen door for the chickens to come in and out) it is isolated and this summer we installed a 5000 BTU AC because we are in texas and temps get very high (over 100F) inside with all the windows open and a fan blowing 24/7. I was worried about my girls having heat strokes while they were laying eggs. With the AC temp inside runs a little over 80F, OK enough of that. Since the coop is closed up, it gets pretty dark inside so I have a 40 watts light that I keep turned on all day. I turn it off in the evening before roosting time and just keep a night light for the night. The times that I have been late getting in to turn the light off, the girls are making a party (I have 6 pullets that act up during roosting time) the other 5 hens are quiet but annoyed. I need a timer that will turn the light on during the day and off at night. Any suggestions?