Re: [LEAPSECS] what time is it, legally?

From: Zefram <zefram_at_FYSH.ORG>
Date: Tue, 12 Dec 2006 20:12:28 +0000

Rob Seaman wrote:
>But this needs a clarification. Standard time replaced local
>apparent solar time in several steps.

Quite so. I glossed over this. The practicalities evolved, and so did
the solutions deployed. The trend has been consistently for increasing
globalisation and (except for DST) predictability.

>All of these remained solar time. Mean solar time of some remote
>location is still a flavor of solar time because there is no secular
>drift.

Mm. I'm wondering how fundamental an aspect that is. If a need arises
for a timescale shared between multiple planets then, projecting the
same processes, parochial planetary rotation would not remain a feature
of the compromise system. But perhaps the same processes don't apply
beyond the planetary level. Perhaps Earth rotation time is not so much
a particular (type of) timescale that can be used in this process but
rather the context within which the process operates. The whole story
that we have looked at here has been about time of day.

Presumably the same processes can operate on interval timescales, as
well as time-of-day timescales. In this context, all these flavours of
solar time *are* just steps on the way. The next step on this path is
to diverge from the time-of-day path.

> The important issue is the continuity of still recognizing
>mean solar time as the foundation of civil time.

That is, civil time has been identified with time of day throughout
this process. I don't think it need remain so indefinitely.

-zefram
Received on Tue Dec 12 2006 - 12:39:42 PST