Skip to main content
U.S. flag

An official website of the United States government

Dot gov

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Https

Secure .gov websites use HTTPS
A lock ( ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

NIST USNO 2009 Archive

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 nanoseconds)

2009-12-31      55196 13 ns
2009-12-24      55189 16 ns
2009-12-17      55182 18 ns
2009-12-10      55175 18 ns
2009-12-03      55168 19 ns
2009-11-26      55161 18 ns
2009-11-19      55154 17 ns
2009-11-12      55147 13 ns
2009-11-05      55140 9 ns
2009-10-29      55133 7 ns
2009-10-22      55126 3 ns
2009-10-15      55119  -1 ns
2009-10-08     55112  -4 ns
2009-10-01     55105  -6 ns
2009-09-24      55098  -8 ns
2009-09-17      55091 -11 ns
2009-09-10      55084 -12 ns
2009-09-03      55077 -13 ns
2009-08-27      55070 -14 ns
2009-08-20      55063 -14 ns
2009-08-13      55056 -14 ns
2009-08-06      55049 -12 ns
2009-07-30      55042 -8 ns
2009-07-23      55035 -6 ns
2009-07-16      55028 -2 ns
2009-07-09      55021 0 ns
2009-07-02      55014 3 ns
2009-06-25     55007 5 ns
2009-06-18      55000    8 ns
2009-06-11      54993 8 ns
2009-06-04      54986 8 ns
2009-05-28      54979 10 ns
2009-05-21     54972 8 ns
2009-05-14      54965 8 ns
2009-05-07      54958 8 ns
2009-04-30      54951 9 ns
2009-04-23      54944 8 ns
2009-04-16      54937 8 ns
2009-04-09      54930 8 ns
2009-04-02      54923 5 ns
2009-03-26      54916 4 ns
2009-03-19      54909 5 ns
2009-03-12      54902 4 ns
2009-03-05      54895 5 ns
2009-02-26      54888 6 ns
2009-02-19      54881 7 ns
2009-02-12      54874 8 ns
2009-02-05      54867 9 ns
2009-01-29      54860   9 ns
2009-01-22      54853 11 ns
2009-01-15      54846 12 ns
2009-01-08      54839 12 ns
2009-01-01      54832 11 ns
Created January 13, 2010, Updated October 7, 2020