[LEAPSECS] Degrees of Accommodating Time Based on Earth Rotation

[Tony Finch]

On Tue, 2 Nov 2010, Poul-Henning Kamp wrote:

>

> Finagle					Subject to

> Factor		Unit/Resolution		politics since

> ------------------------------------------------------------

> Leap days	86400 sec.		2000 bc.

> Timezones	3600 sec.		1884


A better date would be 1845 (first petition to parliament in favour of a
national time zone).


> Leap seconds	1 sec.			1958/1972

> DUT1 (Bul. A)	1 microsec.		Not yet

> ------------------------------------------------------------

>

> Politization of these finagle factors have always been

> motions toward higher predictability:

>

> We went from priests announcing Easter based on astronomical

> observations, to putting them on a mathematical formula that could

> predict the dates for future, as far as we can see it.


There is still an active argument along these lines about how to determine
when Ramadan starts.

Leap days are also an instructive example, since it took about 300 years
for Europe to deploy a revision to the previous standard which had been in
place for about 1600 years...


> We went from random local timescales to UT[C] with 24 standardized

> timezones.

>

> We went from rubber seconds to identical seconds.

>

> In that light, it seems awfully logical that we would want to

> nail the length of the days down also...



Tony.
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