Several people have already addressed most of the important points.
Accurate time needs a specification of time scale and reference
position. STC contains an astronTimeType that may be helpful.
However, let me say emphatically that JD and MJD (and ISO-8601, for that matter), only define something akin to a format and imply nothing about the associated timescale. A JD or MJD without a timescale is meaningless; UTC cannot be assumed.
Patricio F. Ortiz wrote:
>
> Julian Date and Modified Julian Date (which do assume the usage of UTC)
> seem to be one of the most appropriate way of representing such instant
> in time. Using the ISO standard (string representation) is quite common,
> but any application wanting to compare instants in time needs to convert
> it to a floatinng number (double).
>
Arnold H. Rots Chandra X-ray Science Center Smithsonian Astrophysical Observatory tel: +1 617 496 7701 60 Garden Street, MS 67 fax: +1 617 495 7356 Cambridge, MA 02138 arots-at-head.cfa.harvard.edu USA http://hea-www.harvard.edu/~arots/ --------------------------------------------------------------------------Received on 2005-04-22Z23:44:06