I keep hearing about people doing crazy hours like 10 hours a day.
I can only assume that these people are trying to make up for lost time.
I'll be doing 3-4 hours per day, and that's because I started at the beginning of February. I'm pretty-much done.
If you're only starting now or recently, then yeah, 10 hours is probably necessary.
When did you start revising? Are you only just starting?