Ummm....different light hours here and there.....yeah.....that's a big deal. And not be mean...but before you come up with all these reasons for changing things....make sure your PLANTS understand the way you are thinking because nature is telling them something else. Dude....you gotta THINK like a plant.

Even 10 minutes off here and there can cause stress/hermie issues. (for you jchap )
Nature just doesn't work that way. (hmmm....i'm tired....think I'll shut the sun down a few minutes early....)