Let them mature as normal. A decision can be made to give supplemental light when they get near point of lay - after 20 weeks. They will lay when they lay. We don't supplement light as we have heritage breeds that we believe need a break in the fall months during molt. Chickens have a set number of eggs, so not only does supplemental light tax their bodies, but it shortens their laying life (hence the reason heritage breeds often lay eggs at a better rate as they age, even though they aren't as productive in their first years as newer laying breeds and hybrids are. It all depends on what your goal is for your flock. With 11 hens at 1.5 years, we are still getting 1-4 eggs a day during molt because individuals are molting at different times. Not a lot, but enough to keep us from having to buy eggs.