Mina

Your flock's lay rate will slow naturally as the days grow shorter. A chicken needs approximately 14 hours of daylight in order to stimulate her pituitary gland to stimulate the ovaries to release an egg.  In the winter, it can take two or three days to accumulate enough daylight naturally, but to combat the slowed laying many backyard chicken keepers (and all commercial egg farms) add supplemental light to keep lay rates high year round.