I used to ride in the dark 3 times a week most of the year because of shifts that ended between 8-10 pm. During the late evening the roads are much less hectic and I'd get home 5 or 10 minutes earlier than during rush hour. I think the earliest in the morning I ever left home with my bike was around 6:45 and it was still dark out but the sky lightened considerably during those commutes. Too bad I was too sleepy and caffeine deprived to enjoy them.