I have an 8 watt LED light on for 14 hours in the coop sinfe it's dark in there. It goes off around 8pm. The girls know what time it goes off. I've never had one off the roost. Most of them are up on when it starts getting really dark outside. They will be napping in the light when I check them.
The "experts" recommend early morning have the light come on.... have them head to the roost in natural sunset...