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)
2005-12-29	53733	5 ns
2005-12-22	53726	4 ns
2005-12-15	53719	5 ns
2005-12-08	53712	7 ns
2005-12-01	53705	7 ns
2005-11-24	53697	5 ns
2005-11-17	53691	4 ns
2005-11-10	53684	3 ns
2005-11-03	53677	1 ns
2005-10-27	53670	-2 ns
2005-10-20	53663	-4 ns
2005-10-13	53656	-4 ns
2005-10-06	53649	-4 ns
2005-09-29	53642	-4 ns
2005-09-22	53635	-7 ns
2005-09-15	53628	-8 ns
2005-09-08	53621	-9 ns
2005-09-01	53614	-10 ns
2005-08-25	53607	-10 ns
2005-08-18	53600	-10 ns
2005-08-11	53593	-7 ns
2005-08-04	53586	-5 ns
2005-07-28	53579	-2 ns
2005-07-21	53572	1 ns
2005-07-14	53565	4 ns
2005-07-07	53558	7 ns
2005-06-30	53551	7 ns
2005-06-23	53544	9 ns
2005-06-16	53537	9 ns
2005-06-09	53530	7 ns
2005-06-02	53523	7 ns
2005-05-26	53516	4 ns
2005-05-19	53509	3 ns
2005-05-12	53502	4 ns
2005-05-05	53495	1 ns
2005-04-28	53488	1 ns
2005-04-21	53481	2 ns
2005-04-14	53474	0 ns
2005-04-07	53467	-1 ns
2005-03-31	53460	-1 ns
2005-03-24	53453	-3 ns
2005-03-17	53446	-3 ns
2005-03-10	53439	-3 ns
2005-03-03	53432	-2 ns
2005-02-24	53425	-1 ns
2005-02-17	53418	-1 ns
2005-02-10	53411	0 ns
2005-02-03	53404	0 ns
2005-01-27	53397	3 ns
2005-01-20	53390	6 ns
2005-01-13	53383	13 ns
2005-01-06	53376	11 ns

Online: September 2002 - Last update: August 9, 2007 - ep