[LEAPSECS] How good could civil timekeeping be?

David Malone dwmalone at maths.tcd.ie
Fri Feb 15 09:54:36 EST 2008

> > Is that just a paperback version of the 1992 hardcover edition? Any text

> > differences at all?

> A friend tells me there have been some revisions:

> http://fanf.livejournal.com/80822.html?thread=341174#t341174

Someone at the Nautical Almanac Office office told me (in response
to a question about ERA and the defintion of mean sun):

The Astronomical Almanac 2006 contains these definition and
equations. However, I would suggest you wait until the
2007 edition is available (any day now). You should also
note that at the IAU in the summer, there will be proposals
to adopt a better precession model, ie one that is dynamically
consistent and not just an update to Lieskie. This will
probably make some end figure changes in the equations!

I thought that they were suggesting that there was to be an update
to the explainatory suplement in 2006 to explain the ERA stuff, but
now I reread it, it seems likely the information is probably in the
Almanac, not the suplement. I haven't had a chance to look at the
2006 almanac or suplement to confirm this yet.

(I did get to look at some of the almanacs from around 1792 recently,
which have some interesting tibits.)


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