Richard Huxton <dev@archonet.com> writes:
> richardh=# SELECT interval '3' month;
> interval
> ----------
> 00:00:00
> (1 row)
> It's got a zero-length date-range it's comparing against. If you have
> interval '3 months' that should work, but I'm afraid I haven't got time
> to check against the specs to see what the correct format should be.
I think this syntax is supposed to work according to the SQL spec. Tom
Lockhart was fooling around with making that stuff spec-compliant before
he left the project, and no one has bothered to pick it up since :-(.
Perhaps everyone thinks the spec syntax for interval constants is so
bizarre and non-orthogonal it's not worth dealing with ...
regards, tom lane