How do we actually know what the time is? Is there some “master clock” that all time zones are based on? And if so, what does THAT clock refer to?

Question

EDIT: I believe I have kicked a hornet’s nest. Did not expect this to blow up! But I am still looking for the “ur time”. the basis for it all. Like, maybe the big bang, or something.

In: 5399

Answer 1

Noon is set by when the sun is directly overhead if on the equator or due South in the northern hemisphere, due North in the Southern Hemisphere.
World time is set from Greenwich (in London England) going back to Colonial days.