About the light cycle, well, during veg I have the lights to come on at 18:00 and switch off at 12:00. During flowering they'll be on from midnight to midday. I'm a musician so my work hours are during afternoon/evening/nights, depending on if and when there is work available
Like yesterday, I came back at around 01:00 am, and I had some nice time with my plants before hitting the sack. At the same time, having the lights running during the night really helps with the temperature. Remember, southern Europe here... we won't have any snow or freezing temperatures during the winter