There is some interesting discourse on the subject at this site.  Whether it
is true or not...?

http://hermetic.magnet.ch/cal_stud/cal_art.htm

Howard Hoxsie

-----Original Message-----
From: Wirt Atmar [mailto:[log in to unmask]]
Sent: Wednesday, January 31, 2001 12:34 PM
To: [log in to unmask]
Subject: Re: [HP3000-L] date controversy


Ric (and a number of others) write:

> However, even more important to common communication: Look at just about
>  any desk calendar and you will find a day count based on the day number
of
>  the year.  Most people I know refer to this as the Julian day.  It might
>  not be 100% correct, but a lot of non-computer people use it.

Unfortunately, it's not even 0% correct. The "Julian Day" marked on a
standard government calendar is a misnomer: it is merely the number of days
into a year -- and the YYDDD notation form is no more than a Gregorian year
number with a doy number tacked on the backend. It is NOT a Julian Date.

This isn't a problem of proselytizing one arbitrary standard over another,
such as how to properly spell "tyre" and "kerb", it has very fundamental
practical effects. You cannot accurately calculate the number of days from
one arbitrary date to another using this misindentified "julian day" format
-- without first converting the calculation to a true Julian Day format.

Days are the only "real" measure of time we have. You, your cats and dogs,
as
well as bumblebees and horseshoe crabs, all recognize the realities of a
day.
Moreover, calendaric systems change as cultures and religions die and are
born, but day counts remain accurate and easy to use for events separated by
thousands of years.

The starting point for a Julian Date calendar isn't nearly as important as
simply maintaining an accurate count, simply because the primary purpose of
a
Julian Date is to determine the number of elapsed days between two events.

Wirt Atmar