It's fine. Why even have fish if the lights are not on when you are home to enjoy them? I have insomnia and have never been a morning person in general so I have mine set to come on at 4 and go off at 10. The room that most of my tanks are in is not that well lit but there is some light. I don't think they care much. Most of the fish we all keep are from the tropics where they get 12 hours of light and 12 hours of darkness pretty much year round.