Welcome to the forum!
Glad you joined us!
You are talking about starting laying. That's a bit different than continuing to lay through the winter. My first year pullets that start to lay in summer or fall usually lay through the winter and all the next laying season. So if yours start laying, I'd expect them to lay until they molt in fall/winter of 2012.
The latest I have had come into lay was mid-October. Days were shorter than 12 hours, but not by a lot. I've never had any the right age to start later, so I have not experienced that. I've got two this year that should be the right age to start laying sometime in December. Guess I'll find out for myself in another month. Days don't get much shorter than in December and I don't provide extra light.
Commercial operations don't want their pullets to start laying too early. They want the pullets to get mature enough so they will lay decent sized sellable eggs when they lay. The commercial operations control that by keeping the hours of daylight pretty short, 8 or 9 hours maybe, I'm not real sure, then expanding the light to 14 hours a day. The increase in daylight hours tends to start them laying when they are old enough to start laying. With a commercial breed specially bred to start laying at an early age, they know when that is. With our chickens not being those commercial breeds, they can start laying any time, early or real late. We just don't know when ours will start, even in the Spring/Summer.
Don't get hung up on the 14 hours of light the commercial operations use. It works for them with 5,000 laying hens of a certain commercial breed in controlled conditions. The 14 hours is about their feeding schedule and other things than just an absolute requirement of light to lay eggs. Hens fairly close to the equator never see 14 hours of light and do fine. Hens far enough from the equator to see more than 14 hours of light will sometimes molt when the days get shorter, even if 14 hours of light is provided. Chickens adjust. If the four hours extra you are providing was an incease in light, I'd think that will work, regardless of how much light they actually see.
Bottom line is that I do not know if yours will start laying this winter or not. With the extra light you are providing, I expect they will, but mine sometimes slow down in high heat in the summer and those cold spells in the winter. Light is not the only thing that seems to affect laying. I agree you have done what you can. When they are ready to lay, they will.
Good luck!
