Re: Leap Second caution

Jim S (
Sat, 2 Jan 1999 21:10:26 -0500 (EST)

Sorry if I sent a semi-off-topic message to several lists;
 I will trim back on the "CC" addresses.

On Sat, 2 Jan 1999, Rick Walter wrote:
> Date: Sat, 2 Jan 1999 19:42:28 -0500 (EST)
> From: Rick Walter <>
> To: Jim S <>
> Cc: amsat-bb@AMSAT.Org, sarex@AMSAT.Org,,
> Subject: Re: [amsat-bb] Leap Second caution
> Hi Jim.  I have the Radio Shack "Atomic Clock" and it has been right on
> since they first started selling them.  I watched my clock on New Year's
> Eve, and it updated correctly with the leap second added.  It has been
> right on ever since.  The Radio Shack clock updates at 9:00 PM local time.
> Since the extra second was added at 6:59:59 PM, local time (Eastern
> Standard) on December 31, I watched at 9:00 PM local and the leap second
> was added correctly.

Same unit in use here.  The problem is not the leap-second itself, which 
the clock resyncs nicely on its first update after 0000Z.  The problem is 
that the clock thinks that it is has gained one second since the prior 
update, and adjusts its internal time rate to compensate.  This is not 
immediately apparent, but shows as an increasing difference when compared 
to an external reference such as another clock or the WWV time signals.

It's probably only significant to us satellite listeners and/or watchers 
and/or serious demanders of super-accurate time references.   ;)