If an events takes place past midnight should the event have end date the day after; or just the single date.
e.g. a New Years event starting 11pm 31 Dec 2019 finishing 2am 1st Jan 2020: should it have Begin date 2019-12-31 and End date of 2020-01-01 or 2019-12-31?
Yes, it is the same as in your sentence to describe it accurately.
Edit: End time can be entered either as # additional info in event’s setlist, or in event’s annotation.
I don’t think anyone actually thinks of these events as lasting two days, so I would add them as lasting one. But I don’t think we’ve ever reached an actual conclusion about this.
If there are timestamps over midnight in the setlist, then there seems to be not choice but to set two dates, otherwise it probably doesn’t matter indeed.
We also don’t expect an event to be 24 hours long even if start and end date is the same date, so I don’t see why we’d expect an event to be >24 hours long just because it has an end date one day after the start date.
Currently, semantically, if something starts and ends on 2000-01-01 and the track list has something for both 20:00 and 01:00, the only sensible thing to consider this as from a machine standpoint would be to consider that 2000-01-01 20:00 and 2000-01-01 01:00 respectively. Which would, in effect, mean that the event has stretched 24 hours.
Also: