If you read through the Egg Quality Handbook you will see several egg defects that have a possible cause of improper lighting. That normally means too much light or irregular lights. They need a certain amount of dark downtime to perform at their best. There is no magic amount of dark time that is required, you might look at your shortest night to see what might work for you.
Egg Quality Handbook
Lighting plays a big part in their laying and general life cycle. Whether the days are getting longer or shorter plays the biggest role but length of day or night has some influence. A lot of us do not play with the lights but instead let them follow the seasons, but many people do provide lights. There is no real right or wrong way to do this, just different ways we choose for our own reasons. But they do need some dark downtime.