Unless there is a VERY good reason why you can't make it earlier (something such as having children you are responsible for dropping off at certain times) then I think it's an extremely bad idea to ask to reschedule. Particularly since it's only an hour earlier than your normal start time, are you really saying that you can't go to bed and get up one hour earlier for an interview?
Frankly, if I was the interviewer in that situation your resume would immediately go in the "pass" pile even if you were otherwise a stellar candidate, because someone with rigid and unflexible schedules/routines are far more difficult to work with.
Without knowing more about your situation (why the time is a big deal) it's hard to give advice, but I'd strongly suggest you sit down and evaluate why a start time prior to 9:30 is a big deal... because it really shouldn't be. I'm a night owl myself, I'd much rather be up until 2-3am and sleep until 10~ than be up early.
Yet I still drag myself out of bed at 5:30 every morning for work even on days I stay up too late and don't get "enough" sleep, because that's the schedule I work and I value being a good (and reliable) employee more than my "preferred" sleep schedule. Also, getting off earlier in the day is super convenient...