The discussion for STYLE-747 has been fairly clear that most users hate the idea of having events that last until after midnight have an end date of the next day. That makes sense to me, but ideally we'd still have a way to help machines understand a 00:30 or 02:00 performer time does not mean it happened early the previous morning, but the event night. The only way I can think of is a checkbox "this event finishes after midnight" that computers could then use to understand when the performers actually have performed. 

Inevitably there will exist at least one event where some play the early morning of the event day, and it goes on until after midnight. But this should clarify almost all cases.