Do you have the dining plan for both stay's or just one?
If you have just one and it's on the longer stay - it will start the day you check in for that package and includes the number of nights you have - It's good from check in to check out.
If you have it for both stays you have 2 days worth of food that you can use from that check in to that check out. Then on the day you check in for the second package you would have 5 days worth of 5 starting on that day of check in till that check out.
Does that make sense?