Attention, coffee lovers! This Sunday, Sept. 29, marks the official annual celebration of that beloved waker-upper: It's National Coffee Day. Millions start every day with a fresh, hot cup of joe, and on the special day this year, there's free caffeine for all at several big chains. Here are six locations where you can score a free (or in some cases, extremely cheap) cup of coffee and other discounted caffeine products this weekend:

DUNKIN’ DONUTS

Smartphone owners can get a free cup of Dunkin’ Donuts coffee this Sunday by downloading the Dunkin’ Mobile App. The fast-food chain is also celebrating the national holiday by selling its popular Dunkin’ Donuts packaged one-pound bag of coffee, in four best-selling flavors, for the discounted price of $5.99 on Sept. 28 and 29. One-pound bags of packaged coffee can also be purchased online at a discount by using the coupon code: 1BAG. Participating Dunkin’ locations will also be selling the five flavors of the chain’s K-Cup packs at a discounted price of $7.99 for a 14-count box on Sept. 28 and 29. (All discounted merchandise is limited to two items per customer).

STARBUCKS

While caramel frappuccinos and seasonal pumpkin spice lattes are not up for grabs this Sunday, Starbucks is offering customers the chance to get a free taste of its Ethiopian coffee. “Come into a participating Starbucks store this Sunday, September 29, for a taste of our new Ethiopian coffee and discover flavors from the birthplace of coffee,” said the caffeine giant on its official website this week. According to a report from Parade, customers who purchase a one-pound bag of the Ethiopian brew will also recieve a free, commemorative, ceramic Starbucks coffee cup.

KRISPY KREME

Fresh off the chain's National Pirate Day promotion, where it gave free doughnuts to customers for doing their best swash-buckler impersonations, Krispy Kreme will offer each customer a free 12-oz. coffee this Sunday at participating locations in the U.S. and Canada. Mochas, lattes and iced-coffee drinks will be served for only $1.

TIM HORTONS

Utter the phrase “Happy National Coffee Day” to your barista at any U.S. Tim Hortons location on Sunday to receive a free cup of coffee of any size. No coupon is needed to receive your complimentary beverage. Tim Hortons has also teased on its official Facebook page that more “surprises” are in store this weekend for customers who follow the chain's Twitter account: @TimHortonsUS.

KANGAROO EXPRESS

Kangaroo Express isn’t shy about giving customers free merchandise, and National Coffee Day is no exception. Customers can visit any of its 1,500 southeastern U.S. locations Sunday, from 8 a.m. to 12 p.m. and receive a 12-oz. coffee for only one penny.

WAWA

You can get a free, piping-hot cup of coffee from Wawa Inc. this Sunday, but you’ll have to work for it first. The primarily East Coast-based stores are offering customers a free 16-oz. cup of their original brew this Sunday for customers who register online to receive a coupon. (Click here to get register). According to a spokesperson for Wawa on the chain's official Facebook page, coupons will be accepted in stores only in printed form.