From: Will Wagers (firstname.lastname@example.org)
Date: Tue Feb 20 1996 - 14:17:40 EST
David L. Moore writes:
> I was amazed the first time someone (was it you, Will Wagers)
>posted this explanation to the list some time back. I've never come
>across this system of figuring dates labeled "BCE" anywhere else. I'm
>doubly surprised since the astronomy programs for computer that I have
>make no mention of it, and regular B.C. dates work just fine for figuring
>solar eclipses and such that took place in antiquity.
Scholars commonly ignore this distinction, indeed are unware of it. They may
use BCE without compensating. They also commonly do not notify you of which
system they are using when they do make the distinction, e.g. specifying an
It's not necessary in astronomy programs, because they usually use the Julian
Day internally. The Julian Day is the number of days from the _fundamental
epoch_ of noon GMT January 1, 4713 B.C (November 24, 4714 B.C. in the
Gregorian calendar). (This is why the Julian day is n+0.5 instead of n.) The
program is using BC/AD for your convenience. The Julian Day is distinct from
the Julian Calendar system.
It's also common for scientists - e.g. archaeologists, mayanists, etc. - to be
unaware of the distinction.
> Do you have a reference you could cite (preferably in a general
>encyclopedia rather than a specialized astronomy book)?
Uh, no. But, a question to news:sci.astro would generate a few polite answers
to your request. They are very helpful because amateurs have such a strong
role and reputation in astronomy.
I would be interested, privately, if you discover when and why the original
BCE/CE convention was adopted and what it entailed.
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