(CNN) -- Here's some background information about Armed Forces day, a holiday observed in some areas of the United States to honor all branches of the armed forces.
Facts: May 17, 2014 - Armed Forces Day.
It is celebrated on the third Saturday in May.
Other Facts: Each year there is a theme. The theme of the first Armed Services Day was "Teamed for Defense."
It is celebrated with military exercises on land, sea and in the air to honor members of the U.S. military and to show off their state-of-the-art equipment to the civilian population it protects.
Military installations are generally open on that day as it is not a federal holiday.
The United Kingdom and the United Arab Emirates have also united all their country's armed forces under one department and celebrate an Armed Forces Day.
Timeline: August 31, 1949 - Secretary of Defense Louis Johnson announces the creation of an Armed Forces Day to replace separate Army, Navy, Marine Corps, and Air Force holidays. Each branch had its own day of celebration prior to this proclamation.
February 27, 1950 - President Harry S Truman proclaims that "Armed Forces Day, Saturday, May 20, 1950, marks the first combined demonstration by America's defense team of its progress, under the National Security Act, towards the goal of readiness for any eventuality. It is the first parade of preparedness by the unified forces of our land, sea, and air defense."
May 20, 1950 - It is first celebrated. - On this date, 10,000 troops and veterans marched in D.C. in celebration in President Truman's presence. - New York City saw 33,000 participants in their air show ceremony. - Parades, air shows, receptions, and other celebrations take place as well.