If you want maximum egg production, through the winter months, you want them to get 14-16 hours of light daily. This usually entails adding a light to the coop.
Also if they are still allowed to range in a run or outside, I personally believe it's best to supplement that light in the morning... Have the light come on about 14.5 hours before your sunset (need to adjust every few weeks) and turn off about an hour after sunrise or when you open the coop door... This allows the birds to get a natural sunset and allows them to get the signal of the dimming light as an indicator to return to the coop for the night and also allows them to get comfortable before it gets dark... This prevents sudden lights off, although even with sudden lights off (like in full time coop housed chickens) they will become accustomed to the hours of light and roost an hour or two before the lights switch, and/or you can put in a night light (red works well) so they can still sort of see and get around if needed, a very dim light like a night light isn't enough to stimulate them into thinking it's daytime but gives them some light...
I posted this on another query, this is how I do it, works extremely well, hope it helps: There are a lot of opinions on supplementing light to keep the chickens laying during time period where there is less than 12-14 hours of available daylight. My coop gets 16 hours of light 351 days per year. I turn lights off for 14 days to have birds go into a controlled moult late September . Having had to install electricity for the thermostatically controlled water heater, I took advantage and installed a lighting system. My system has two timers. The first is set to turn the lights on at 5:30am, off at 9pm. Power goes on, passes through a photocell, then to a 300 lumen LED bulb, 4.8 watts, in the 8x8 foot print coop, and 2 4.8 watt LEDs for the 14x14 foot print outside run. I light the run because I found the birds huddled outside the coop door in the dark one 5:30am morning... They have access to the run 24/7, as it is as secure as the coop. The lights are on only when it is dark enough outside to be necessary. The time on very closely mimics my Summer Solstice in NJ. The second timer is set to go on at 8:30pm, off at 9:30pm, a diffused 200 lumen LED 4 watt bulb. This low light allows the birds to settle in before all lights out and 8 hours of darkness. This system costs less than $5 per year to operate..
