Mission Accomplished Day

On September 11, 2001, Osama bin Laden directed the attacks that struck the World Trade Center and the Pentagon. The Iraq War began on March 20, 2003.
On May 1, 2003, President Bush showed up in a flight suit to declare an end to major combat operations in Iraq. (He was never actually a combat pilot; he just played one on TV.)
Neil Young describes the stunt in the song "Shock and Awe" on his new album, Living with War:

Back in the days of “mission accomplished”
Our chief was landing on the deck
The sun was setting on a golden photo op
Back in the days of “mission accomplished”

That was 1,096 days ago. It has now been 1,693 days since we were attacked. Osama bin Laden is still at large.