On 19/09/2014 13:48, Max Leske wrote:
Ok, so I read Chris’ e-mail and I’m intrigued.
Sven, you’re still right about financial months being 30 days for instance but
the thing is that the current implementation seems broken (or inconsisten at
least) and doesn’t honor that case either. *Not* making the change will not
help us either…
So I’d say: let’s do it. If somebody objects (or proposes a change) then we can
handle that but at least we can claim that we try to give the users what we
preach, like writing natural language like code (e.g. “x + 1 month” which is
currently not possible).
That’s my view at least. Also: we’re changing so much stuff in Pharo anyway all
the time, I don’t think this would hurt.
That comment re 30 day months in financial is not totally correct.
A common reason for calculating days in a financial calculation is for
interest calculation and then you don't just need a number for the day
difference but also for the number of days in a year. When I did this I
think I had to support many ways of calculating the fraction of a year
that was the difference between two dates depending on the interest
basis (ie the contract terms) , Wikipedia gives 11
<http://en.wikipedia.org/wiki/Day_count_convention>
So I think that adding a financial number of days into a basic date
object does not make sense as it will not be correct in many cases. The
best way I have seen is to pass a daycount basis strategy class into the
calculation and that strategy object does the calculation.
--
Mark
