Calendar Types

[Glynn Clements]

Bayley, Alistair wrote:

> > You also need to specify, or let the user specify, the order of
> > arithmetic.  I.e. adding a day and then a second is different from
> > doing it the other way around.

Only when leap seconds are involved. A month and a day would be a
better example.

> Duration arithmetic is not commutative? Can you give some examples please,
> because I'm not able to imagine any.

	April 30th + 1 month + 1 day = May 30th + 1 day = May 31st
	April 30th + 1 day + 1 month = May 1st + 1 month = June 1st

-- 
Glynn Clements <glynn at gclements.plus.com>