Brendan,
> There are two classes of intervals. One class, called year-month
> intervals, has an express or implied datetime precision that includes
> no fields other than YEAR and MONTH, though not both are required. The
> other class, called day-time intervals, has an express or implied
> interval precision that can include any fields other than YEAR or
> MONTH.
Yeah, we used to do that. It sucked. In fact, most developers of
applications which were calendar-heavy ended up using custom data types to
work around the SQL-spec INTERVAL limitations. And that benefits nobody.
We modified our INTERVAL type to function in ways that calendar application
developers (of which there are several on this list) can actually use.
See discussion leading up to the 8.0 release.
--
--Josh
Josh Berkus
PostgreSQL @ Sun
San Francisco