Re: 'cal 9 1752' and emacs calendar disagree

[Nic James Ferrier <nferrier@tapsellferrier.co.uk>]

Leon <sdl.web@gmail.com> writes:

> Hi there,
>
> For some historical reasons¹, September 1752 is a special month that
> has no 3 - 13 dates. As you can see, 'cal 9 1752' will gives
>
>    September 1752   
> Su Mo Tu We Th Fr Sa
>        1  2 14 15 16
> 17 18 19 20 21 22 23
> 24 25 26 27 28 29 30
>
>
> While emacs calendar gives:
>
>    September 1752    
> Su Mo Tu We Th Fr Sa 
>                 1  2 
>  3  4  5  6  7  8  9 
> 10 11 12 13 14 15 16 
> 17 18 19 20 21 22 23 
> 24 25 26 27 28 29 30
>
> Is this a bug?

No. Unix cal is badly broken in respect of understood calendrical
systems.

Ordinary calendars are consistent within a calendrical system. So if
we accept and use the Gregorian Calendar we count backwards with it as
well as counting forwards.

It does not matter that in a particular locale the Gregorian system
was started on a particular date. Only that a particular locale uses 
the Gregorian system.

Unix cal is only right if you happen to be English or you are American
and accept England's conversion to the Gregorian calendar as the date
when the colonies were converted as well.

But if you are Russian or French or Mexican there is absolutely no
reason to think of cal's 9 1752 behaviour as being in any way
sensible.


-- 
Nic Ferrier
http://www.tapsellferrier.co.uk   for all your tapsell ferrier needs