I did a test. Dusk is 7:48pm. My automatic door closed at 7:33pm. Two days in a row it thought dusk is 15 minutes earlier than it is. The door with a light sensor is inside the coop so I'm not blaming the sensor there are windows but I think it's pretty darn accurate for being indoors. I believe I can make adjustments on it too close a certain amount of minutes after dusk I could be wrong I need to look at the paperwork again otherwise I can set a specific time. Question let's pretend dusk is at 7:48 p.m. where you live tonight what time will your chickens go back into the coop? Estimates are fine. Thank you!