In the military, D-Day is the day on which a combat attack or operation is to be initiated. ... However, many other invasions and operations had a designated D-Day, both before and after that operation. The terms D-Day and H-Hour are used for the day and hour on which a combat attack or operation is to be initiated.

Why was it called D-Day?

The 10 Things you Need to Know about D-Day. ... On D-Day, 6 June 1944, Allied forces launched a combined naval, air and land assault on Nazi-occupied France. The 'D' in D-Day stands simply for 'day' and the term was used to describe the first day of any large military operation.

What does the D of D-Day stand for?

The most widely acknowledged explanation for why that event is remembered as “D-Day” is a straightforward one. The “D” stands for “day.” ... The term H-Hour worked similarly, with “H” referring to the time on D-Day when the Allied troops hit the beaches. (H-Hour was 6:30 a.m. local time for the Normandy landings.)