The Longest Day (FOX 1962)

Let's play a game this week.

Ask people what this Sunday is.

I can bet that half of the people you ask will have no idea.

Here is the movie review of The Longest Day from IMDb...

The retelling of June 6, 1944, from the perspectives of the Germans, the US, Britain, and the Free French. Marshall Erwin Rommel, touring the defenses being established as part of the Reich's Atlantic Wall, notes to his officers that when the Allied invasion comes they must be stopped on the beach. "For the Allies as well as the Germans, it will be the longest day. The longest day."

I wish I could have found a trailer on the web that didn't totally suck, but I did find this clip...