Across the U.S., donut distributors – large and small – also participate in National Donut Day; big names Dunkin' and Krispy Kreme, which officially call them "doughnuts," will be giving away free donuts on June 6.

National Donut Day also celebrates the Salvation Army "Lassies," or women who served doughnuts to soldiers during WWI. National Donut Day is on Friday, June 6, and several chains are offering deals for the annual unofficial food holiday.

Whether you spell it "doughnut" or "donut," you can enjoy a free treat at various stores on Friday in celebration of National Doughnut Day.