Re: "two time periods with only an endpoint in common do not overlap" ???

On 10/14/21 7:02 PM, Adrian Klaver wrote:
[snip]

or the third example in the docs:

SELECT (DATE '2001-02-16', DATE '2001-12-21') OVERLAPS
       (DATE '2001-10-30', DATE '2002-10-30');
Result: true
SELECT (DATE '2001-02-16', INTERVAL '100 days') OVERLAPS
       (DATE '2001-10-30', DATE '2002-10-30');
Result: false
SELECT (DATE '2001-10-29', DATE '2001-10-30') OVERLAPS
       (DATE '2001-10-30', DATE '2001-10-31');
Result: false

Why don't they overlap, given that they share a common date?