Ha, you should see my schedule. We have seven periods, numbered 1-7. These correspond to specific classes. The day is cut up into six blocks, lettered A-F. These correspond to specific time slots. But wait, you say, why are there seven periods but only six blocks? Well, the answer is that there is a career education facility attached to the school, and the kids who go there have to go out into the community to do projects. Every day, one period is left out and the periods are all mixed so that those kids can go out for half days, but not miss too much class. There's a seven day rotation, and the period left out is the one with the same number as the day. Thank heaven for small favors. This schedule would be impossible otherwise. Also, lunch comes in waves during D block, so not everyone eats at the same time. It gets worse, though, because there are four different periods that rotate through D block. This means that during the course of a week, you might eat lunch at up to four different times, from as early as 10:30 to (still early, imo) 11:36.