NIST Time Scale Data Archive Updated monthly

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2001

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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

Date	MJD	UTC(USNO)-UTC(NIST) (+/- 20 ns)
2007-12-27	54461	4 ns
2007-12-20	54454	5 ns
2007-12-13	54447	5 ns
2007-12-06	54440	6 ns
2007-11-29	54433	7 ns
2007-11-22	54426	8 ns
2007-11-15	54419	7 ns
2007-11-08	54412	7 ns
2007-11-01	54405	7 ns
2007-10-25	54398	8 ns
2007-10-18	54391	7 ns
2007-10-11	54384	6 ns
2007-10-04	54377	4 ns
2007-09-27	54370	2 ns
2007-09-20	54363	0 ns
2007-09-13	54356	-1 ns
2007-09-06	54349	-3 ns
2007-08-30	54342	-4 ns
2007-08-23	54335	-4 ns
2007-08-16	54328	-4 ns
2007-08-09	54321	-2 ns
2007-08-02	54314	-4 ns
2007-07-26	54307	-3 ns
2007-07-19	54300	-3 ns
2007-07-12	54293	-2 ns
2007-07-05	54286	-1 ns
2007-06-28	54279	1 ns
2007-06-21	54272	3 ns
2007-06-14	54265	4 ns
2007-06-07	54258	4 ns
2007-05-31	54251	6 ns
2007-05-24	54244	9 ns
2007-05-17	54237	11 ns
2007-05-10	54230	12 ns
2007-05-03	54223	15 ns
2007-04-26	54216	15 ns
2007-04-19	54209	16 ns
2007-04-12	54202	15 ns
2007-04-05	54195	16 ns
2007-03-29	54188	19 ns
2007-03-22	54181	20 ns
2007-03-15	54174	21 ns
2007-03-08	54167	21 ns
2007-03-01	54160	21 ns
2007-02-22	54153	23 ns
2007-02-15	54146	23 ns
2007-02-08	54139	23 ns
2007-02-01	54132	25 ns
2007-01-25	54125	26 ns
2007-01-18	54118	28 ns
2007-01-11	54111	28 ns
2007-01-04	54104	26 ns

Online: September 2002 - Last update: January 2, 2008 - ep