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UTC(NIST) Time Scale

Coordinated Universal Time, abbreviated as UTC, is the official, internationally agreed upon standard for world time. The National Institute of Standards and Technology (NIST) maintains its own representation of UTC, called UTC(NIST), which serves as the official time standard for the United States. This was codified into law by the America COMPETES Act of 2007 which states that the official time for the United States is Coordinated Universal Time (UTC), as “interpreted or modified by the Secretary of Commerce, in coordination with the Secretary of the Navy.” Because NIST is the division of the Department of Commerce responsible for maintaining the U. S. standards of physical measurement, the passage of this bill formally established NIST as the official U. S. timekeeper.

Of course, NIST was well established and recognized as an official United States timekeeper long before the passage of the America COMPETES Act. The first implementations of the UTC(NIST) time scale were built in the 1960s, more than half a century ago, by NIST’s predecessor, the National Bureau of Standards. In subsequent years, the time kept by UTC(NIST) became the official time reference for numerous sectors of U. S. industry, including stock exchanges and the electric power sector.

To learn more about UTC(NIST), please visit the following sections:

Section 1 – Introduction to UTC(NIST)

Section 2 – How UTC(NIST) Works

Section 3 – Performance of UTC(NIST) and UTC(NIST) Adjustments

Section 4 – Reliability of UTC(NIST)

Section 5 – Secondary UTC(NIST) Time Scales and UTC(NIST) Distribution

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Created November 18, 2020, Updated November 19, 2020