National Coffee Day 2024 Dunkin. This national coffee day, sunday, september 29, dunkin’ rewards® members can enjoy a free medium hot or iced coffee with purchase through the dunkin’ app*. For national coffee day on sunday, members of the dunkin' rewards loyalty program can get a free medium hot or iced coffee with any purchase (limit one per member;.

National coffee day 2024 is almost here! Here’s how you can claim yours: