My understanding is that you can use the credits in any order, that is, 2 counter service one day, 2 sit-down meals the next. You could have a late character breakfast and a sit down in the late afternoon, or 2 counter service meals in one day. It's your choice. Also, if you run out of counter serviced credits, you can use a sit-down at a counter-service place. Not the best value, but it makes it more flexible.