[nindalf]

And we're going to say "let's do this a day from now", leaving the software to decide whether that's 24, 23 or 25 hours from now. It could be any of those things, depending on where it was said and the DST changes for that timezone.

Or conversely, is a specified instant considered "tomorrow"?

[freeopinion]

I generally consider "tomorrow" to be an interval and not an instant. It is ambigous how large of an interval it is and how far in the future it begins.

[berkes]

"tomorrow" in the real world is also surprisingly complex.

I once built a calendar and reservation system for a theatre that did movies, theatre, concerts and parties. A party that starts Friday at 22:00 and ends at 1:30 doesn't end "tomorrow" in people's minds, it ends Friday night.

(And a party, concert or movie that technically starts Sunday, 00:15 still has to show up on Saturday night 00:15, because that's how everyone looks for it)

[nindalf]

"Tomorrow" is an interval. I meant to say, is a specified instant within the "tomorrow" interval?