On 10/15/21 8:59 AM, Adrian Klaver wrote:
On 10/15/21 06:52, Ron wrote:
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?
Per the docs:
https://www.postgresql.org/docs/current/functions-datetime.html
" Each time period is considered to represent the half-open interval start
<= time < end, unless start and end are equal in which case it represents
that single time instant."
Which I read as
(DATE '2001-10-29', DATE '2001-10-30') ends at '2001-10-29'
and
(DATE '2001-10-30', DATE '2001-10-31') starts at DATE '2001-10-30'
so no overlap.
I was afraid you were going to say that. It's completely bizarre, but seems
to be a "thing" in computer science.
--
Angular momentum makes the world go 'round.
