Everyone is obviously different, but in my opinion, 3 months of dedicated studying (more than 5 hours a day) is around the max amount of time one could study without getting burnt out. Plus you'd start to run into diminishing returns. You could stretch it out if you wanted to study less per day. Although, if you don't have to, I don't see a point. Might as well get it done with. If I were in your position I would figure out a how long I wanted to study for, find a study schedule to fit that time table, get after it, and then enjoy the rest of your gap year before school starts. I actually just made a video of what I'm doing with my gap year...links in my signature. I am loving life right now, and so ready to hit the books this fall. Good luck, I'm sure you are going to dominate.
