Newbie: Subtracting Dates

[John Machin]

Dennis Lee Bieber <wlfraed at ix.netcom.com> wrote in message news:<5shosa.ar3.ln at beastie.ix.netcom.com>...
> mowestusa fed this fish to the penguins on Thursday 05 December 2002 
> 11:39 am:
> 
> > 
> > It seems that programing date addition and subtraction is harder than
> > I
> > realized.  I'm wondering if Python offers anything to help with this. 
> > I would also like to know of some web resources that I could read
> > about
> > programming and working with dates.

Web: Try the Calendar FAQ http://www.tondering.dk/claus/calendar.html

> >
>         There's a whole book on the subject (I think it may be in a second 
> edition by now).
> 
>         Calendrical Calculations
>         Nachum Dershowitz & Edward M. Reingold
>         1997 Cambridge University Press

Yes; called the Millenium Edition. Good historical stuff, well
written. All the algorithms are shown in Lisp which may present a
problem for those not familiar with that language. Some of the basic
engine-room functions (e.g. gregorian-from-fixed) are written in
expository fashion and are gloriously inefficient under some
definitions of efficiency.

Another good book:
Mapping Time -- The Calendar and its History
E.G. Richards
OUP 1998
ISBN 0-19-286205-7