Thanks to Steve Allen, Joseph Myers and Jim Ray for comprehensive
answers to my two recent questions.
I wrote:
> > ... did
> > TAI-UTC vary during the course of a single UTC day?
Steve Allen replied:
> For practical purposes it still does. See
> http://www.boulder.nist.gov/timefreq/pubs/bulletin/nistat1.htm
Well yes, though this rather depends on your definition of
"practical". There is a significant difference between
millisecond level trends in the *definition* of UTC relative
to TAI and sub-microsecond level wobbles in particular
*implementations* of UTC. For many applications the best
available approximation to UTC, from the 1PPS output of a GPS
receiver, is at the microsecond level anyway.
Ed.
Received on Fri Jun 27 2003 - 03:20:44 PDT