The Dining Plan credits are yours to use as you want. You don't have to use use 1CS or TS per day. You could use 2TS in a day no CS and all your snacks on one day if you choose. So you don't lose any credits unless you haven't used them on by your check out day. They are good until midnight after you check out.
If he is booked for dinner and lunch one day. I'd book a really nice 2TS meal for one of the days he'll be able to dine with you.