Man, it's weird seeing people with more than 4 periods, lol. I prefer the system we have here: In my school, we have the jr. and sr. lunches staggered because we don't have a big enough cafeteria, but it goes like this:
Jr.
Week1....Week2....Week3....Week4
Class 1...Class 2...Class 3....Class 4
Class 2...Class 1...Class 4....Class 3
lunch......lunch.....lunch......lunch
Class 3...Class 4...Class 1....Class 2
Class 4...Class 3...Class 2....Class 1
Sr.
Weeks are arranged the same, but in this order instead
Class 1...Class 2...Class 3....Class 4
Class 2...Class 1...Class 4....Class 3
Class 3...Class 4...Class 1....Class 2
lunch......lunch.....lunch......lunch
Class 4...Class 3...Class 2....Class 1