bug#20583: calendar-absolute-from-gregorian

[Glenn Morris]

Nicholas Strauss wrote:

> Why does (calendar-absolute-from-gregorian '(10 10 1582))
> return 577731?
> (calendar-generate '(10 1582)) is another example of this
> error.

It's behaving as designed. It's a utility function that operates on the
basis that today's calendar system is valid for all time. It's not meant
as literally historically accurate, and I think trying to make it so (by
introducing discontinuities at certain dates) would be a mistake. See eg
thread at:

http://lists.gnu.org/archive/html/emacs-devel/2006-07/msg01008.html