If you use left-inclusive, right-exclusive intervals [), then then the overlap condition is: meeting_a.starts_at <= meeting_b.ends_at && meeting_b.starts_at <=

If you use left-inclusive, right-exclusive intervals [), then then the overlap condition is: meeting_a.starts_at <= meeting_b.ends_at && meeting_b.starts_at <= meeting_a.ends_at So, indeed, the scenario as described in the article is more complex than needed.