

Even though there is a day night cycle, the time for sunrise varies by location anyways (and they also change during different time of the year)
We already arbitrarily decide a number to be “morning” anyways, what’s the harm in having each place have their own time range for “morning”?
It’s mostly with how society decides that the standard office hours is 9-5, if we are not restricted by such constraints, then it really matters less.
Why even decide what is noon? Sam works from 1600 to 0000, so when we want to have a meeting with Sam we just take in consideration of that time range, screw letting the sun dictate how we live our lives. (This also makes it friendlier to nocturnal people)