[Python-Dev] Issue5434: datetime.monthdelta (original) (raw)

Jess Austin jess.austin at gmail.com
Thu Apr 16 20:50:29 CEST 2009

On Thu, Apr 16, 2009 at 5:16 AM, Dirkjan Ochtman <dirkjan at ochtman.nl> wrote:

On Thu, Apr 16, 2009 at 11:54, Amaury Forgeot d'Arc <amauryfa at gmail.com> wrote:

In my opinion: arithmetic with months is a mess. There is no such "month interval" or "year interval" with a precise definition. If we adopt some kind of month manipulation, it should be a function or a method, like you would do for features like lastdayofmonth(d), or followingweekday(d, 'monday').

 date(2008, 1, 30).addmonths(1) == date(2008, 2, 29) I concur. Trying to shoehorn month arithmetic into timedelta is a PITA, precisely because it's somewhat inexact. It's better to have some separate behavior that has well-defined behavior in edge cases.

This is my experience also, and including a distinct and well-defined behavior in the core is exactly my intention with this patch.

More information about the Python-Dev mailing list