[time-nuts] On Setting the Astronomical Time

[Tom Van Baak]

> Setting your clock using GPS time, or with the known offset UTC is straight 
> forward.  Offsetting UTC using the posted value of DUT1 gets you UTC1 good to 
> 0.1 seconds.  But that's 8 orders of magnitude away from the precision of UTC.

Correct. See plots of earth accuracy and stability:

http://www.leapsecond.com/museum/earth/

> Is there some way to get TT to better than a tenth of a second, or is the earth 
> just too sloppy of a time keeper?

Don't know for sure but the following may help you:

http://maia.usno.navy.mil/
http://www.iers.org/MainDisp.csl?pid=36-9
http://maia.usno.navy.mil/ser7/finals.daily
http://maia.usno.navy.mil/search/search.html

My recollection is that using VLBI, UT1 is measured to
sub-millisecond even microsecond levels.

For example, yesterday UT1-UTC was -148.709 ms, today
it is -149.996 ms, and tomorrow it will be -151.172 ms.

/tvb