Yes, they cancel each other out. It's total cumulative hours flown for that bid. If it's over awarded line guarantee you get paid the extra hours. To make it easy, if you have one leg left on the last trip of the bid. And you're projected to be one hour over block using that last legs scheduled block. Then, you end up blocking in 30 minutes early, now your only paid .5 hours more for the bid instead of the 1.0.