Re: [LEAPSECS] building consensus

From: John Cowan <cowan_at_CCIL.ORG>
Date: Mon, 5 Jun 2006 19:25:00 -0400

Rob Seaman scripsit:

> I presume you aren't asserting that standard time clocks can't be
> accurate, but rather distinguishing between standard (timezone)
> time and local mean solar time?

No, I am reflecting the fact that some people define "local civil time"
in such a way as to exclude daylight-saving shifts.

> On the other hand, all I've ever meant by the term "civil time" is
> that time that a well educated civilian sets her clock in order to
> agree with other civilians for civilian purposes.

Good. That is what I mean also.

> Interesting question: On similar historical occasions, for instance
> during the transition from "old style" to "new style" dates as the
> Julian calendar gave way to the Gregorian, has the sequence of days
> of the week remained unbroken? Or rather, have days of the week been
> skipped as well as days of the month? Surely the Gregorian calendar
> is not just a rule for adding a leap day every four years (except
> sometimes), but also includes the definitions of the twelve months,
> and an initialization of a specific day-of-the-week on whatever date.

During the British transition, at least, the days of the week continued
their accustomed rotation. I believe this was true of every such
transition as well. Even while part of Europe was Gregorian and part
Julian, they all agreed on when Sunday was, most fortunately.

> >This was not a calendar transition, but a (drastic) time zone
> >transition involving moving the International Date Line to the east.
> Not obvious that there is any difference - kind of a calendrical
> Mach's Principle.

It is precisely the fact that there was no Wednesday in the Philippines
in that final week of 1845 that made it a time-zone rather than a
calendrical transition.

John Cowan
If he has seen farther than others,
        it is because he is standing on a stack of dwarves.
                --Mike Champion, describing Tim Berners-Lee (adapted)
Received on Mon Jun 05 2006 - 16:25:24 PDT

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