<<While astronomers do have a real and pressing need for a
calendaric method to count the number of days from any point in time to any
other, the selection of midnight, November 17, 1858 (which by the way, was
the date I inferred from your previous notes), has no more relevancy as a
starting point than any other for a "modified Julian Date".>>


Anyone can certainly use any reference they choose, of course. It's really a
terminology issue: calling any such arbitrarily-chosen date style a "Julian
date" is incorrect, because that term already has a specific,
explicitly-defined meaning. And, since Scaliger defined the term in 1583,
he's got both Microsoft and AICS Research beat hands-down from a precedence
aspect.

I agree that the actual offset value for the MJD seems pretty arbitrary; I'm
guessing that it was driven by criteria like getting the date numbers down
to relatively small digit counts, using an easy-to-remember offset (2.4
million plus the half-day), and getting back to a midnight-based demarcation
between days. But, since it was selected over 40 years ago, I'm not sure who
we'd ask.

Unfortunately, calling such date styles "Julian dates" is probably pretty
much in the same category as referring to a single-humped "ship of the
desert" as a "camel", or thinking that a sentence like "I will, hopefully,
hear something by tomorrow" is grammatically correct; all of them are wrong,
but all of them are used daily by millions of people, the majority of whom
are not only ignorant of the proper usage, but are unaware that the issue
even exists. For that matter, we could even re-open the discussion about
"what is the first day of the 21st century?" Or not.

Steve