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Physical Measurement Laboratory / Time and Frequency Division

Time Realization and Distribution Group

This page is no longer being updated and the information may be out of date.

NIST USNO 2004 Archive

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UTC(USNO) - UTC(NIST)

The United States Naval Observatory (USNO) and the National Institute of Standards and Technology (NIST) make regular comparisons of their respective time scales. These comparisons are made using GPS common-view measurements from up to approximately 10 GPS satellites. The table below lists recent differences between the two time scales.

Weekly UTC(USNO, Master Clock) - UTC(NIST)Values

DateMJDUTC(USNO)-UTC(NIST) (+/- 20 nanoseconds)
2004-12-30  5336910 ns
2004-12-23  5336213 ns
2004-12-16  5335513 ns
2004-12-09  5334814 ns
2004-12-02  5334116 ns
2004-11-25  5333414 ns
2004-11-18  5332713 ns
2004-11-11  5332011 ns
2004-11-04  5331310 ns
2004-10-28  5330610 ns
2004-10-21  5329911 ns
2004-10-14  5329212 ns
2004-10-07  5328511 ns
2004-09-30  5327811 ns
2004-09-23  5327111 ns
2004-09-16  5326413 ns
2004-09-09  5325711 ns
2004-09-02  532507 ns
2004-08-26  532436 ns
2004-08-19  532364 ns
2004-08-12  532293 ns
2004-08-05  53222-1 ns
2004-07-29  532150 ns
2004-07-22  53208-3 ns
2004-07-15  53201-2 ns
2004-07-08  53194-1 ns
2004-07-01  53187-1 ns
2004-06-24  53180-1 ns
2004-06-17  531730 ns
2004-06-10  531663 ns
2004-06-03  531597 ns
2004-05-27  531529 ns
2004-05-20  5314513 ns
2004-05-13  5313817 ns
2004-05-06  5313117 ns
2004-04-29  5312418 ns
2004-04-22  5311717 ns
2004-04-15    5311014 ns
2004-04-08  5310310 ns
2004-04-01  530964 ns
2004-03-25  530891 ns
2004-03-18  53082-1 ns
2004-03-11  53075-2 ns
2004-03-04  53068-6 ns
2004-02-26  53061-12 ns
2004-02-19  53054-15 ns
2004-02-12  53047-11 ns
2004-02-05  53040-17 ns
2004-01-29  53033-21 ns
2004-01-22  53026-22 ns
2004-01-15  53019-24 ns
2004-01-08  53012-21 ns
2004-01-01  53005-19 ns
Time and frequency
Created January 13, 2010, Updated January 2, 2026
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