"Dean Gibson (DB Administrator)" <postgresql3@ultimeth.com> writes:
> 3. x - y < INTERVAL '...' doesn't work (but then, the minus operator is not
> defined in the manual for two DATE values).
Sure it is: see 10th row in
http://www.postgresql.org/docs/7.4/static/functions-datetime.html#OPERATORS-DATETIME-TABLE
Forget the interval and compare to an integer.
regards, tom lane