The light in my coop comes on at 3:00 am and turns off @ 9:00 am. It is still pitch black until about 8:00-8:30 am. The last few nights I have forgotten to close the coop door, so the birds have free range to the run. Each morning I check on them before I leave for work @ 5:00 and have discovered that those crazy chickens leave their lighted coop to go stand in the dark until the sun comes up. So I am guessing that from 3:30ish to @ 8:30ish they are without light (by choice). I have not seen a change in egg production yet, but I only have two out of the 8 that are laying. The rest have not started yet. If this happens too often, will it mess up their egg laying clock.