They will lay when their bodies tell them to lay. A healthy chicken will lay consistently, whatever that means for that chicken. It could mean 7-days a week, 5 days a week or 3 days a week. But even if you aren't expecting an egg every day, you want to provide a proper and balanced diet for your birds. Layer is just the right balanced diet for a hen in her first couple of years. It has the right amount of protein, calcium, minerals and vitamins for her to lay. When it is time to moult (late summer early fall) she will shed the old feathers out and grown new and should look like a new happy hen when it is over. That too takes protein (to grow new feathers) so the diet is still very important at that time, and that is why they may drop off or stop laying.