Re: Interval subtracting

Stephan Szabo wrote:
> > justify_days doesn't currently do anything with this result --- it
> > thinks its charter is only to reduce day components that are >= 30 days.
> > However, I think a good case could be made that it should normalize
> > negative days too; that is, the invariant on its result should be
> > 0 <= days < 30, not merely days < 30.
> 
> What about cases like interval '1 month -99 days', should that turn into
> interval '-3 mons +21 days' or '-2 mons -9 days'?

I think it should be the later.  It is best to have a single sign, and I
think it is possible in all cases:
'2 mons -1 days'

could be adjusted to '1 mons 29 days'.

--  Bruce Momjian   http://candle.pha.pa.us SRA OSS, Inc.   http://www.sraoss.com
 + If your life is a hard drive, Christ can be your backup. +