From OPM's Website:
President George W. Bush To Close Federal Offices in Tribute to Former President Gerald R. Ford
Washington, D.C. -- By Executive Order of President George W. Bush, all executive departments, independent organizations and other agencies of the Federal government shall be closed on Tuesday, January 2, 2007, as a mark of respect for Gerald R. Ford, the 38th President of the United States.
U.S. Office of Personnel Management (OPM) Director Linda M. Springer notified Cabinet Secretaries, Agency Heads and Chief Human Capital Officers governmentwide about the closure shortly after President Bush signed the Executive Order on December 28, 2006. Springer provided agency leaders with a copy of the President's proclamation, which designates Tuesday, January 2, 2007, as a National Day of Mourning.
The closure order includes Federal offices, with the exception of those offices and installations, or parts thereof, in the Department of State, the Department of Defense, the Department of Justice, the Department of Homeland Security, or other departments, independent organizations, and governmental agencies whose agency head determines should remain open for reasons of national security or defense, or other essential public business.