I have similar questions. We did go ahead and put up a 25-watt light about 2 weeks ago that extends the day to 15 hours of light. I am confused how that fits in with other information I have read, such as "don't suddenly add light in the coop when the pullets are coming into lay," and "they slow down when they molt in the fall," and "peak production is at 30 weeks." Those things don't seem to add up to me!! Our pullets are about 22 weeks old and some are laying, but I am not sure we are doing everything right. Now that the light is on a timer we are going to leave it that way and adjust it to come on earlier as the days get shorter here. I also read that you should only extend the day in the morning and never at night because extending it at night denies the chickens of the gradual settling-in time that they have in the evening when the sun sets. I have watched ours and it takes them a good half hour to kick each other off of the perches and get settled for the night, and there are only 9 of them and they have plenty of perching choices!! I think only extending the day in the morning makes a lot of sense. We live pretty far north and I keep thinking latitude must have something to do with when the pullets mature, but I haven't seen any info on that yet.