"Stephen R. van den Berg" <srb(at)cuci(dot)nl> writes:
> Intervals are a scalar, not an addition of assorted values, alternating signs
> between fields would be wrong.
Sorry, you're the one who's wrong on that. We've treated intervals as
three independent fields for years now (and before that it was two
independent fields). We're not going to throw away that capability.
regards, tom lane