D-Day was when the Allied Forces landed in Normandy on June 6, 1944. Here is a quiz to test your knowledge.
What It Was Called
The invasion of Normandy was called Operation Overlord. Operation Neptune dealt specifically with the amphibious landing in Normandy. 
When It Happened
The attack was scheduled for June 5, 1944, but due to rough seas, they attacked on June 6, 1944.
Now test your knowledge of D-Day with The Epoch Times quiz here.