Mine get kicked out into the cold in the daytime around 7.30am and get put back into the duck house at 4.30pm. They only get the slightly above freezing temps at night with an oil filled radiator. Light goes off at 6pm and comes on at 3am. So 9 hours of darkness and 15 hours of light. That is also the max they get in summer naturally. They were still laying with only 18 degrees in the daytime. That was also when they only got their small pen with hay on the ground. They get the large outdoor area as soon as it gets above 20 degrees. I have this measure in place to prevent frost bite. So yes a little heat does help with egg production. Doesn't need to be much, 35-40 degrees is all that is needed.