[LEAPSECS] LOD reaches 0 s/d

[Joseph Gwinn]

On Thu, 12 Nov 2020 23:45:52 +0000, Poul-Henning Kamp wrote:
> --------
> 
>>     predicts that d(UT2)/d(TAI) = 1 after 2021-11-13, ie
>>     the rates of UTT2 and TAI are expected to agree for the
>>     next year. This has never happened since 1961. We may
>>     not need to abolish leap seconds for quite a while.
> 
> Unless of course we get close enough to a negative one, that people
> are *really* going to freak out.
> 
> Hands in the air:  Who here besides Warner and me has ever tried to
> test handling of negative leap-seconds ?

Twenty years ago, I tested a very large radar for the general effect 
of a leap second by arbitrarily causing the local clock by one 
second, in both directions.  Radar software gyrated and settled down 
on the inserted leap second, and really gyrated on a deleted second.  
But nothing failed.

This tests mostly the radar tracking software, and not leap second 
handling per se.  The radar passed - the momentary gyration was not a 
problem in practice.

Joe Gwinn