In message <4D4A90A1-13F0-4BB4-9DCE-257836391165_at_noao.edu>, Rob Seaman writes:
>> 2. Julian Date (JD)
>>
>> [...] For that
>> purpose it is recommended that JD be specified as SI seconds in
>> Terrestrial Time (TT) where the length of day is 86,400 SI seconds.
Let me see if understood that right: In order to avoid computing
problems and to get precise time, astronomers rely on a timescale
without leapseconds, because the Earths rotation is too unstable
a clock for their purposes.
And in N years, for some value of N, JD's will start at midnight
instead of noon in Greenwich.
"Don't do like we do, do as we say..."
Yes, the irony is rather notable.
--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
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Never attribute to malice what can adequately be explained by incompetence.
Received on Tue Jan 10 2006 - 10:17:05 PST