Of course, the Julian calendar is available in Emacs, as are the Hebrew,
Chinese, etc.

On Fri, Oct 5, 2012 at 2:13 PM, Jay Belanger <jay.p.belanger@gmail.com>wrote:

>
> Calc and the Emacs calendar use different calendar systems.
> From the Calc manual:
>   Calc uses a combination of the Gregorian and Julian calendars,
>   following the history of Great Britain and the British colonies.
>   This is the same calendar that is used by the `cal' program in most
>   Unix implementations.
> and from the Emacs manual:
>   The Emacs calendar displayed is _always_ the Gregorian calendar,
>   sometimes called the "new style" calendar, which is used in most of the
>   world today.  However, this calendar did not exist before the sixteenth
>   century and was not widely used before the eighteenth century; it did
>   not fully displace the Julian calendar and gain universal acceptance
>   until the early twentieth century.  The Emacs calendar can display any
>   month since January, year 1 of the current era, but the calendar
>   displayed is always the Gregorian, even for a date at which the
>   Gregorian calendar did not exist.
> So, for example, the day before September 14, 1752 is
> September 2, 1752 according to Calc and September 13, 1752 according
> to the calendar.
>
> Is this acceptable, or should they be made consistent?
>
> Jay
>
>