Interesting for me. This is the first year that we decided to add lighting to the coop to see if egg production went up. The egg production has gone down! I got far more eggs the last few years without artificial lighting.
Now, a couple of factors that may be playing a part in this info.
My hens had already decreased their laying when we finally got the lights up and running last fall. I think the lights should have been on about a month before we actually got them working.
Some of my hens are going on 4 years old. But, even my one and two year olds aren't laying like they were in the fall.
Second, I had a really rough Rooster and, for about a month, four cockerals (they hatched here last summer and I haven't been able to find them homes) who were mercilessly harassing my hens. I've moved all five boys into their own area now and still am not getting many eggs.
I also have at least one egg eater. I'm trying to figure out who it is and if I'm losing eggs that I don't even know were laid.
It is suggested to always add light in the morning hours and let the sun go down naturally in the evening so the chickens know when to go into roost. They can get 'caught' in the dark if an added light all of a sudden just goes off. Thus, my lights come on at 2:00 a.m. and shut off at 8:00 a.m. They are on a timer.
I may try this experiment again next year and see if things go differently.