Re: Unifying Atomic Time and the post-Gregorian calendar corrections

From: Steve Allen <>
Date: Thu, 3 Jul 2003 09:15:36 -0700

On Thu 2003-07-03T15:20:19 +0100, Markus Kuhn hath writ:
> d) Whenever British Time is about to fall 12 h behind TI, UN/ITU/IERS (or
> the Queen of England :) will write to all heads of government worldwide
> and invite them to agree that the next year divisible by 400 shall not
> be a leap year (except for anything living in TI or course) in all
> countries.

> This will keep local times and TI from diverging by more than about a
> day or 25 h (for British Time the divergence will even be limited to
> about half a day or 13 h):
> 5496: British Time = TI - 11h
> 5600-02-28: British time = TI - 11 h (5600-02-29 skipped in civilian time)
> 5600-03-01: British time = TI + 13 h
> 5658: British time = TI + 12 h
> 5814: British time = TI + 11 h
> 5963: British time = TI + 10 h

Okay, but in the Caves of Steel where people use TI-based timekeeping
5600-03-01 is a Wednesday, and in the UT-based lands where the sun
determines when people work and sleep 5600-03-01 is a Tuesday.

> This way, we have a time and calendar system with three nice properties:

The day of the week is one property Markus did not mention, and it is
a little bit weird. Globetrotting travelers experience something like
this now when they fly through the day they might normally worship,
but at least they are allowed to use the same calendar in most places.

> d) The spring equinox will (hopefully) remain more stable at the same
> day of the year than if we kept UTC with the Gregorian calendar, because
> the year length follows closer atomic time than the UT day length.
> (On the last point, I'm still looking for confirmation from
> astronomers with good knowledge of long-term prediction of the
> longitude of the sun.) GOOD!

I am not convinced that there is anyone who does long-term solar
system stability studies who would be willing and able to comment on
this in an authoritative fashion. It's just too far into the future.

If the other problems posed by UT vs. TI are solved by a new
broadcast time system it should be sufficient, and not really
inconsiderate, to leave any equinox/calendar problem to posterity.

Steve Allen          UCO/Lick Observatory       Santa Cruz, CA 95064      Voice: +1 831 459 3046
PGP: 1024/E46978C5   F6 78 D1 10 62 94 8F 2E    49 89 0E FE 26 B4 14 93
Received on Thu Jul 03 2003 - 09:15:48 PDT

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