On 'National Ballpoint Pen Day' and 'National Lost Sock Memorial Day' some may begin to wonder if there is a national day for nearly every item and event that has ever existed.

While the holidays mentioned above might raise a few eyebrows, this month includes a nationally celebrated day that most people would appreciate.

National Coffee Day is recognized on September 29, and according to CNN, it's also a day when the U.S.'s 64 percent of daily coffee drinkers can score a cup of Joe for free.

Here's how:

Starbucks

Customers who bring a "clean, empty, reusable cup" into any US location can get in return a 20 fluid ounce cup of the chain's signature Pike Place brewed coffee on the house. 

Starbucks recently reinstated a program that lets customers bring in their own mugs, after a temporary COVID-forced pause in 2020.

Dunkin'

Dunkin' is giving away one free medium hot or iced coffee with any purchase to members of its DD Perks loyalty program. Cold brew is excluded.

Einstein Bros. Bagels

Customers always get a free coffee when they order in the company’s app.

7-Eleven

Similar to Dunkin', the convenience store chain is offering a coffee of any size for free with the purchase of a baked good to members of its 7Rewards loyalty program.

Krispy Kreme

The doughnut chain is giving away free coffee and a free doughnut to member of its rewards program. However, those that aren't members can still get a free coffee.

Wawa

Wawa is giving away a free coffee of any size all day Wednesday at its roughly 900 locations across the East Coast. 

Wendy's

Get a free hot coffee when you purchase any breakfast sandwich at participating locations.

Of course, before dropping by any of the above locations in person, it may be a good idea to call the restaurant or store and make sure it's participating in the special.