google says..... What is the meaning of D-Day? A lot of people ask me what does D-Day actually means. Well, every operation has it's D-Day. This is the day an operation starts. For operation Overlord this was June 6th 1944, for operation Market Garden this was 17 September 1944, and so one. Instead of just saying, Day, they repeat the first letter to emphasize that this is the day that the operation will start, not on any other day, but this day! The same counts for H-Hour, this is the time the operation will start. Like for the invasion in Normandy, H-Hour for Omaha Beach was 06.30h. In French they say "le Jour-J" for D-Day, In Dutch they say "het Uur-U" for H-Hour, according to the same principle.
But since the invasion in Normandy was one of the most important in WW II, and also because it's the most popular, and one of the most fascinating events from WWII, the operation has gone into history as D-Day. One of many of the history errors. The actual name for the invasion is Operation Overlord.
