On 19 Sep 2014, at 14:59, Esteban A. Maringolo <emaringolo@gmail.com> wrote:
2014-09-19 9:16 GMT-03:00 Sven Van Caekenberghe <sven@stfx.eu>:
Part of that is in https://pharo.fogbugz.com/f/cases/13229/Year-arithmetic-broken
Furthermore, I am not so sure all this is a good idea, year/month durations are not constants and are dealt with differently in many context (say the financial world).
+1
January 30 + 1 month ? January 31 + 1 month ? Februari 29 2004 + 1 year ?
And given all sorts of cleverness, will basic math rules still work ?
A +B = B + A A + B = C => C - B = A
Pharo Date/DateAndTime are incremental[1], then all this week/month/year operations will simply add/subtract the increment from epoch.
The only way to do this in a deterministic way is to have a field based Date.
Saying that it is not deterministic is a bit harsh ;-)
Regards!
Esteban A. Maringolo
[1] http://www.w3.org/TR/2005/NOTE-timezone-20051013/#d2e310
Very interesting link, really useful - Thx.