Re: Concalendrical reference point

John Cowan writes:
 > Tim May scripsit:
 > >
 > > Note that this thread is of marginal topicality, but I can't think of
 > > a better place to ask.
 > >
 > > I've been trying to develop a calendar.  It's just a standard calendar
 > > for use on Earth, with no speacal concultural associations.  I'm
 > > fairly happy with the mechanics of the thing, but one question
 > > troubles me - from what date to start the long count of years?  I
 > > could just start it from when I finish the calendar (or that year,
 > > anyway - I'm thinking of having the year start at the vernal equinox,
 > > like the Vorlin calendar) but that seems to perhaps attach too much
 > > importance to the creation of the calendar itself.  I'm unable to
 > > So one idea I
 > > had was to simply take the earliest recorded event which can be
 > > precisely dated (at least to the year) with a reasonable degree of
 > > certainty. So my question is, does anyone know what that event is?
 >
 > Such things are pretty unstable.  Do you count something like
 > "oldest living tree sets seed"?  We know that date quite accurately
 > from tree-ring counting.
 >
That's an interesting suggestion, but older bristlecone pines are likely
to be found.  I believe the location (though possibly not the age) of
the oldest now known is kept secret to discourage souvenir-hunters.
The previous record holder's extreme age was realized only after it
was cut down, to the consederable remorse of the researcher responsible.

 > I would recommend instead that you use the year 4173 B.C.E.
 > It is comfortably before the beginning of history, and is the base
 > date for the Julian day count: 2452421 days ago.  This date was
 > chosen as the year in which three different cycles were all in
 > registry: the 28-year solar cycle of the civil year, the 19-year lunar cycle
 > of the Babylonian/Jewish year, and the arbitrary 15-year cycle
 > of the Roman tax year.
 >
That's a good idea, and I'll certainly consider it.