Celebrate National Coffee Day with a cup of joe

(CNN) — It’s time to caffeine up, because today is National Coffee Day.

A number of coffee, restaurant and grocery chains are offering free or discounted coffee for the day. They include Dunkin’ Donuts, Krispy Kreme, McDonald’s and Whole Foods.

Some other chains are going the charitable route, like Caribou Coffee. For every cup of coffee sold today, the company is donating one to nurses and families in cancer centers.

Meanwhile, Starbucks is launching a tree-planting initiative.