I do an early snack too because of early arrivals and serve at 8:30 which gives everyone a chance to arrive and even those that come at 8 having just had breakfast can manage to eat something at 8:30 to top them up. It is a more breakfast type snack like dry cereal and fruit or toast or muffin and milk. It is then only 3 hours till lunch - long enough to get hungry but not so long they are famished. My early arrivals start at 6:30-6:45 and they manage to wait till 8:30 too. I do adjust the serving size for those that were the earliest compared to the latest arrival.