try a timer set to turn on 3am and off after dawn. let them go to roost with natural light at dusk. make sure they have food to fill their crawl for roosting and food when the light is turned on in the am. mix a few ounces of crushed hot peppers into their layer mash, might kick start the egg laying.
My hens wake up with natural light at about 6am and go to bed with their extended lighting, in the run and coop. In the coop we have a 25w inc, and in the run a 60 watt incandescent both on the same X10 timer. It comes on at 4pm (1/2 hour before dusk is the setting) and at 7pm, they dim about 20% every 12 minutes. Around 7:30 I can look out and see through the window that they're beginning their bed-time routine a couple of them will be on the roost. By 7:45, the light is dim enough that they can get into the coop and roost and it goes off at 8pm. Only had one or two occasions where they are roosting outside or one on the floor in the corner of the roost. I put my own kids to bed then go out and tuck them in and bring a lantern with me so that anyone who didn't make it up in time (rare occurrence) can get up to the roost. The first one laid at 20 weeks to the day in September, and they have been steadily starting since then, and the last one finally laid her first egg this week! 6/6, awesome!