8:30. My hours aren't all that terrible, but after burning the candle at both ends for the better part of a decade of grad school, I'm a little worried about burning out.
Cycling might help with the burn-out. The exercise is good for you. Getting out of a stressful drive is good for you. Etc. Even if the ride is a bit longer, it's probably a net positive. Especially if you end up at the gym or jogging anyways - you get to double-count the bike commute as part of your workout.
You didn't mention riding after dusk as a problem, but there are plenty of good bike light options available now. LEDs and batteries have come a long way in the last 5-10 years and small, rechargeable lights are now powerful enough to provide adequate lighting for nighttime commutes (some are even bright enough for daytime use - so cars see you better).
Thanks for the lighting tips. I'm actually taking some urban cycling classes next month. I think at this point I need knowledge and confidence to make cycling a part of my commute.