The "possibly duplicate events" report does not account for the situation where one event is a parent event of another (e.g. Roadburn Festival 2007 and Roadburn Festival 2007, Day 1). The report can check if two potential duplicates are in a "part of" relationship with each other. Another possible solution is to not regard a date range as equal to a date inside that range (e.g. the festival took place on 2007-04-20 – 2007-04-22, while day 1 took place on 2007-04-20; these dates are now seen by the report as the "same date").