I don't add extra light. They are free range though so they do get some. Most of the ones laying right now hatched this summer so they are just getting into laying. There are some that hatched last summer that are not however. My older birds might end up being processed though. Unless they pick up in the spring. 

 I’ve been giving mine an extra hour and a half of light before dawn and again after dark in the winter. Been working well now for 3 years.