I live in a college town with like the third largest party school in California. I love riding at night, especially the weekends when everyone is out on their porches and downtown drinking. Sure it's the craziest time to ride, but that also makes it the most fun to me. Just have a bright flashing light on your back so you don't get hit from behind, and I see know difference in safety from the day.
Most the time when i'm out at night, i've been out for a while and don't have my headlamp with me. I don't see a huge need for it. I can see well enough with the moon and whatever streetlights there are. I pretty well have the potholes and speed bumps all memorized, and I prefer cars not to see me from the front. I know what a car is going to do if I'm not there. But if they do see me, I can't know if they will wait, go, creep, speed. A predictable driver is a much safer car.