At busy 24 hour airports, plenty of flights are scheduled to depart at 23:55, 00:05, and sometimes even 23:59 and 00:01, but I've never seen one scheduled at 00:00 exactly. Preventing passenger confusion seems to be a good reason not to do this (plenty of people already show up the wrong day to flights between midnight and 1 am), but are flights ever scheduled to depart anywhere at midnight anyway, present or past? Or are there technical reasons not to do this as well?

Similarly, flights also don't seem to be scheduled to arrive at exactly midnight either, even though there's no risk of passengers showing up on the wrong day in that case.