If your return time for Guardians of the Galaxy: Cosmic Rewind falls at the same time that you have a dining reservation, don’t worry. Head to dinner. After you eat, if the Cast Member tells you that you missed your time, just show him or her your dinner receipt. You should then be allowed on with no problem. Chances are, though, that no one will ask you.
Here are Parts One, Two, Three, Four, Six, and Seven of this series.