On June 6, 1944 the Allied Forces stormed the beaches at Normandy to liberate Europe from Nazi control in World War II. The event is commonly referred to as “D-Day” and an episode of Today I Found Out episode gives several different possibilities for what the “D” stands for, including the most probable one.
You might at first be inclined to think the abbreviation is similar to V-Day (Victory Day). Indeed, one commonly touted explanation given for the meaning of the “D” in D-Day is that it stands for “designated day.” Others claim it stands for “decision day”, “debarkation”, or even “deliverance day.” Even General Dwight Eisenhower, or at the least his assistant, weighed in when Eisenhower received a letter asking for an explanation of the meaning of D-Day. His executive assistant wrote back stating D-Day was a shortened version of “departed day”.