Armed forces day is celebrated this year on May 21st. It was created by President Harry S. Truman. He led the effort to establish a single holiday for citizens to thank our military members for their patriotic service and all they do for our country. On August 31, 1949, Secretary of Defense Louis Johnson announced the creation of an Armed Forces Day to unify the branches. The single day celebration stemmed from the unification of the Armed Forces under the Department of Defense. There used to be individual celebration days for each (Army Day, Navy Day, Air force Day, Marine Corps Day, and Coast Guard Day).