Re: [Ntp] Timescales

[Steve Allen <[e-mail]>]

On Wed 2020-12-09T14:06:50+0100 Magnus Danielson hath writ:
> The most robust solutions is creating a time-scale that is some
> well-defined shift from TAI, and then provide the TAI-UTC difference
> explicitly along with a pre-warning system. Look at for instance GPS [1]
> and PTP [2]. I've chosen this path myself and it has worked very nicely.
>
> So, this is not a crazy idea, it's robust engineering proven in battle.
>
> What is problematic is able to support backward compatibility to the
> classical NTP time-scale as this needs to be handled in all time-stamps.

The extended discussion in the NTPWG now is strikingly similar to the
arguments in the late 1960s which resulted in leap seconds.
A 1969 report analyzing the options pointed out that leap seconds
would cause problems in precise timing systems used for navigation.
Backward compatibility concerns forced the international agreement to
have leap seconds.  Before the first leap second the technical members
of the committees proceeded to change their operational systems to use
purely atomic time with no leaps, and that choice was repeated for
GPS, Galileo, BeiDou, etc. because it was the only robust way.

--
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