NIST Time Scale Data Archive Updated monthly

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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)
2004-12-30	53369	10 ns
2004-12-23	53362	13 ns
2004-12-16	53355	13 ns
2004-12-09	53348	14 ns
2004-12-02	53341	16 ns
2004-11-25	53334	14 ns
2004-11-18	53327	13 ns
2004-11-11	53320	11 ns
2004-11-04	53313	10 ns
2004-10-28	53306	10 ns
2004-10-21	53299	11 ns
2004-10-14	53292	12 ns
2004-10-07	53285	11 ns
2004-09-30	53278	11 ns
2004-09-23	53271	11 ns
2004-09-16	53264	13 ns
2004-09-09	53257	11 ns
2004-09-02	53250	7 ns
2004-08-26	53243	6 ns
2004-08-19	53236	4 ns
2004-08-12	53229	3 ns
2004-08-05	53222	-1 ns
2004-07-29	53215	0 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	53173	0 ns
2004-06-10	53166	3 ns
2004-06-03	53159	7 ns
2004-05-27	53152	9 ns
2004-05-20	53145	13 ns
2004-05-13	53138	17 ns
2004-05-06	53131	17 ns
2004-04-29	53124	18 ns
2004-04-22	53117	17 ns
2004-04-15	53110	14 ns
2004-04-08	53103	10 ns
2004-04-01	53096	4 ns
2004-03-25	53089	1 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