As John has said its up to yourself when you darken the loft ,say from 6 pm until 8am or 7pm till 9am it's up to you ,put up some kind of blinds it don't have to be pitch black ,they should still be able to see the drinkers ,and everything else as normal, the aim is to make them think it's the winter months .it's the way to fly YB .IMO ,good luck if you decide to try it .