Charles:
The
Disney Dining Plan is very flexible as to when and how you use your credits. Even though you may not be able to get into your room, you can actually check-in at your resort as early at 8 a.m. on your arrival day and your credits are good until midnight of the day you check out of your resort.
You will be given dining credits based on how many nights you will be staying at your Disney resort. For example, if you are on the basic Disney Dining Plan and staying 5 nights, you'll receive 5 table restaurant credits, 5 counter service credits and 5 snacks. You may use your credits from the time of check-in where you like, all in one day or spaced out over the entire length of your stay.
So to answer your question, on your arrival day, you may use your credits immediately for an afternoon tea or dinner or save them to double up on your departure day for lunch. It's your choice.
Wishing y'all a magical vacation!
Whitney