On Thu, 2009-10-29 at 16:39 -0700, Scott Bailey wrote:
> But there is some ambiguity around the length of a month. So INTERVAL '1
> month - 30 days' = INTERVAL '0 days' = INTERVAL '-1 month +30 days'.
> But when added to a date, it makes no change for months with 30 days,
> adds 1 day for months with 31 days and subtracts 2 days for February.
Yes, that is a strange case. When you can't tell if an interval is
positive or negative, how do you define the absolute value?
I think that's a strong argument not to provide an absolute value
function for INTERVALs.
Regards,
Jeff Davis
