Today is National Doughnut Day, according to the website nationaldaycalendar.com.

The day is said to celebrate the doughnut and honors the Salvation Army Lassies, the women that served doughnuts to soldiers during WWI each year on the first Friday in June. 

According to the website, in 1917, the original "Salvation Army Doughnut" was first served by the ladies of the Salvation Army. It was during WWI that the Salvation Army Lassies went to the front lines of Europe. Some say home cooked-foods, provided by the brave volunteers, were a morale boost to the troops.

The doughnuts were often cooked in oil inside the metal helmets of American soldiers. American infantrymen were then commonly called "doughboys."

The website says on this day, many bakeries and coffee shops in the United States may offer doughnut deals to their customers.