How important is the timing of my meals and snacks? I am on the 4 block meals and 2 block snacks schedule.

I attempt to go to bed by 10pm each night because I get up around 5:15am and exercise around 6:15-6:30. I eat breakfast before my workout, but should I split my breakfast in half and eat part before my workout and part after?

Also, I read where the final snack of the day should be eaten around 11pm, but I'm not usually up that late. I know I'm supposed to eat every 5 hours, but sometimes the timing is quite difficult. I've been pretty disciplined about eating the correct amounts, and I rarely "cheat." How concerned should I be about my meal timing?

The basic timing rules are important in order to stay in the Zone. I've never heard of the 11P time for the bedtime snack. It's meant to be eaten close to bedtime, whenever that is for you, with it's puropse being to prevent hypoglycemia while you sleep. Your blocks can be split however works best for you, as long as you follow the timing rules and don't eat more than 5 or 6 fully balanced blocks at one time.