[LEAPSECS] alternative to smearing

Steve Allen sla at ucolick.org
Mon Jan 9 16:52:29 EST 2017


On Mon 2017-01-09T22:45:19 +0100, Preben Nørager hath writ:
> Julian days count solar days.

No, Julian days count days.
Those can be "days" in whatever time scale.

The astronomical almanacs had a longstanding set of tables expressed
in Julian Ephemeris Date (J.E.D.) which was a count of days of
Ephemeris Time.

J.D. can equally be used for "days" of TAI, or any other timescale.
As noted by the IAU recommendation two decades ago, it is important
for the user to specify which time scale is being used for those days.

--
Steve Allen                    <sla at ucolick.org>              WGS-84 (GPS)
UCO/Lick Observatory--ISB 260  Natural Sciences II, Room 165  Lat  +36.99855
1156 High Street               Voice: +1 831 459 3046         Lng -122.06015
Santa Cruz, CA 95064           http://www.ucolick.org/~sla/   Hgt +250 m


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