The Department of Defense master clock is the atomic master clock to which time and frequency measurements for the United States Department of Defense are referenced. Located in Washington D.C., the U.S. Naval Observatory master clock is designated as the "DOD Master Clock". It is one of the two standard time and frequency references for the

U.S. Government The federal government of the United States (U.S. federal government or U.S. government) is the national government of the United States, a federal republic located primarily in North America, composed of 50 states, a city within a fede ...

in accordance with Federal Standard 1002-A. The other standard time and frequency reference for the U.S. Government is the National Institute of Standards and Technology (NIST) master clock. In 2018, it was proposed to replace the existing Clock House building it's housed in, designed by

Richard Morris Hunt Richard Morris Hunt (October 31, 1827 – July 31, 1895) was an American architect of the nineteenth century and an eminent figure in the history of American architecture. He helped shape New York City with his designs for the 1902 entrance fa� ...

, with a new facility. The U.S. Naval Observatory also maintains an alternate clock designated "USNO Alternate Master Clock" at Schriever Air Force Base, Colorado.

References

{{reflist Clocks in the United States United States Department of Defense