What 'D-Day' means

POSTED 6/6/01 BEDFORD, Va. (AP) -- The ‘‘D’’ in D-Day means simply the ‘‘day’’ of a planned attack. Military commanders would calibrate their calendars to the D-day (and the H-hour) of an operation so everyone would work from the same reference point. For example, ‘‘D-3’’ would mean three days before D-day. ‘‘H+75’’ would mean 75 minutes after the attack. The term dates at least as far back as World War I, when an army officer wrote in an American Expeditionary Forces order on Sept. 7, 1918: ‘‘The First Army will attack at H hour on D day with the object of forcing the evacuation of the St. Mihiel Salient.’’ ‘‘D-Day’’ eventually became synonymous with June 6, 1944, the day of the Allies’ famous invasion of Normandy that proved to be a turning point in the war.