Re: CLDR Usage of Gregorian Calendar Era Terms: BC and AD -- Can we please have "CE" and "BCE" ?

From: Hans Aberg (
Date: Thu Dec 20 2007 - 08:37:16 CST

  • Next message: Marion Gunn: "Re: CLDR Usage of Gregorian Calendar Era Terms: BC and AD -- Can we please have "CE" and "BCE" ?"

    On 20 Dec 2007, at 13:17, James Kass wrote:

    >> The simplest way to avoid the issue altogether is to use
    >> astronomical year numbering:
    > A good idea, but the phrase "astronomical year numbering"
    > may be too cumbersome for many. We'd want something
    > simpler and more catchy. How about "star date"?

    It got its name from its use in astronomy, not from stars, and "star
    date" is already in use:
    and not very well defined :-).

    But one might call it "astronomical calendar" or "common calendar",
    which is not any harder than "Gregorian calendar", agreeing that in
    the Julian Day (JDN) counting starting day 0 at January 1, -4712,
    every year divisible by 4 is a leap year, until October 4, 1582,
    which is followed by October 15, 1582, where-after years divisible by
    100 but not 400 are excluded from being leap years. This produces a
    well defined calendar.

    The thing is that the Gregorian calendar was only introduced
    gradually by different countries, and is still not used for example
    by the Russian Orthodox church
    So tying the suggestions to the Gregorian calendar may not have the
    intended effect :-). It is also rare to see "AD" or "A.D." on modern
    dates, and "CE" means something else in the Europe

    So formally, one tends to use the astronomical calendar when dealing
    with modern dates, but switching to another calendar, the Julian or
    Gregorian calendar, when dealing with older dates. There, one might
    think the appropriate method would be to either quote the dates as
    written (as the historical records might be unclear of calendar
    syncing), or translate them into the modern astronomical calendar as
    a benefit to modern readers. It takes a long time bringing forth the
    full acceptance of the symbol 0 and negative numbers - those Medieval
    habits are strongly ingrained :-).

    As for calendar computations, it is simplest to provide computations
    back and forth to Julian Day Numbering (if possible, in view of that
    historical records might be unclear). Users can then use whatever
    calendar they prefer - it is just a matter of display in a modern
    computer, if dates are stored internally as JDNs.

       Hans Åberg

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