You could assume that a day isn't exactly 24 hours, but it's close-ish to 24 hours. Nope, not even close.

And that assumes that we can treat an hour as a precise measure of time (we can't). On some systems, even a second is not a precise measure of time (second smearing).

To make things worse, those are "simple" edge cases.

Time is hard. I'm not sure if I can make any statement about time that is true.