https://www.mercurynews.com/2021/09/29/where-to-get-free-coffee-and-doughnuts-on-national-coffee-day/

(CNN) — To mark National Coffee Day — Wednesday, Sept. 29 — Starbucks, Dunkin’ and other chains will give away a variety of freebies. Here’s a look at some of this year’s deals:

For one day only, Starbucks is offering free coffee: Customers who bring a “clean, empty, reusable cup” into any U.S. location can receive a gratis cup of the chain’s signature Pike Place brewed coffee.  Starbucks is limiting the free fill-ups to 20 fluid ounces, the size of a large mug.