[tz] Coordinated Universal Time (UTC) to retain “leap second”

[Marshall Eubanks]

On Fri, Nov 20, 2015 at 12:16 AM, Random832 <random832 at fastmail.com> wrote:

> On 2015-11-20, Paul Ganssle <paul at ganssle.io> wrote:
> > At least they seem to be deferring decision rather than
> > actively deciding in favor of leap seconds. Still, is anyone
> > actually advocating in favor of leap seconds? Who is being
> > helped by keeping mean solar time at noon UTC or whatever the
> > point of leap seconds is?
>
> I got into an argument about this with ESR (in an NTPsec
> announcement thread on his blog) a few months ago and he said:
>
> > You think a timescale which is an integer number of seconds
> > offset from TAI and which is within a second or so of London’s
> > Mean Solar Time is wholly unnecessary. This demonstrates that
> > you aren’t a marine navigator, an astronomer, or (where it
> > bites especially hard) an aviator. It’s from these people that
> > the real-world pushback against decoupling international
> > standard time from mean solar is coming, and they have good
> > reasons.
>
> So, those people, I guess. It's still not entirely clear to me
> why they need civil time coupled to it, but there you go.
>
>
The only reason (at least, until UT1-TAI builds up to 2 or 3 hours) is
celestial navigation using civil time, which should be good to half a km or
so just using UTC clock time.

Note, by the way, that the Navy is worried about hacks to the navigation
infrastructure sufficiently to make celestial mechanics a required course
once again at the Naval Academy.

http://www.latimes.com/nation/la-na-celestial-navigation-20151025-story.html

Regards
Marshall Eubanks
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