[LEAPSECS] The relation between Easter and leap econds.

[Tony Finch]

On Sun, 9 Nov 2008, Peter Bunclark wrote:

>

> So a User requirement might be:

> The rythms of life, including the orbits of the earth and the moon,

> the rotation of the earth, and convenient sub-divisions of the rotation

> down to nearly the limit of human perception, shall be expressed in

> a single monotonic calendar.


I guess you mean the limits of human perception as assisted by suitable
tools...

Most common calendars have given up trying to track both the moon and
the sun. Most of them prefer to track the sun; the Muslims track the moon;
and the Jews track both and the result is impressively complex.

Your specification doesn't capture how to measure the rotation of the
Earth. We used to use apparent solar time, then we switched to local
mean solar time, then we switched to standard time, then we added
arbitrary unpredictable seasonal offsets.

My point is that user requirements change. The relation between natural
phenomena and our consensus idea of time depends on how accurately and
quickly we can measure those phenomena, and which phenomena we care about
tracking.

Tony.
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