Post #62 goes over this. Even my local large airport (O’Hare) has about a dozen or so flights each night that leave between midnight and 2 a.m. I count 15 for today.
I… think I agree with you: It looks analogous to me because it’s a matter of definition. Midnight isn’t automatically, inherently, inevitably part of one day, or the next, or neither, but we could choose to designate it in any of these ways.
I thought midnight always belonged to the next day. On New Year’s Eve, when the clock strikes 12, it is the next year…so wouldn’t that mean that midnight belongs to the next day on any random day?
Not necessarily. Another interpretation is that, if you are hearing the clock strike midnight, that means it’s already past the midnight point and is now the next day/year.
Ah, I grok what you are saying. It wasn’t clear to me before. My apologies. 
No. This has been explained over and over again in this thread.
Right but it’s still confusing because according to this thread (as I understand it), 12:00 am is today, but 12:01 is tomorrow. Just seems weird & illogical.
ETA that not everyone seems to agree on this.
24-hour clock (to simplify):
0000 = today
0001 = today
…
2300 = today
2359 = today
2400 = today = 0000 tomorrow
0001 = tomorrow
The statement that the “instant” of midnight might belong to the day ending rather than the new day was a hypothetical rhetorical suggestion only; do not get confused thinking there is such a standard.
The instant of midnight *does *belong to the day ending rather than the new day. It is by convention. There is no reason we couldn’t have another convention that is different, but this is the convention that we have. If you choose to disregard this convention then you might just as well decide there are 100 hours in a day and 100 minutes in an hour, because you think it makes more sense that way.
You still don’t understand it then. According to the AM/PM system* THERE IS NO 12:00 AM. It doesn’t exist. Nothing. Nada. Nohow. Noway.
Midnight belongs neither to today nor tomorrow. It’s between the days.
*As noted, there may be some conventions that designate noon or midnight as being AM or PM, but there is no real consensus on this.
What convention? I think of midnight generally as beginning the day (no doubt influenced by 0:00 of the 24-hour clock), so Tuesday midnight to me means the zero hour between Monday and Tuesday. But it depends on the context. If something is ending at midnight, I assume it belongs to the day before. If something is starting at midnight, the day starting.
(Personally, I always says something like “midnight Monday going into Tuesday” for things like this.)
I will capitulate my position. There are some conventions used where 12:00 PM means noon and 12:00 AM means midnight. However, for the sake of anchoring this discussion to some authority I will refer to the (U.S.) National Institute of Standards and Technology.
I will continue to maintain that there no particular reason that it has to be this way, and it is by convention. But if the U.S. government says this is the convention, who am I to argue?
Which convention are you referring to? You quoted something from the NIST that says various things, including that 12am and 12pm are meaningless.
Maybe you skipped this part:
After doing a little research I have found that the reason that standards are so great is that there are so many of them. There is much disagreement on this but I have decided to go with the federal agency responsible for setting standards. Which is different than where I started out.
Ref xkcd: Standards