When the sun is directly overhead it's meant to be 12:00 - IN THEORY! However as Timezones are pretty wide, most of the time you'll be at least 15 minutes out.

When the sun is directly overhead it's meant to be 12:00 - IN THEORY! However as Timezones are pretty wide, most of the time you'll be at least 15 minutes out. Sometimes you'll be out by as much as 3 hours - and you've probably never even noticed! Telescopes already have to compensate for this (as well as for summer time). Leap seconds make a shambles of book keeping too. What is "2022-07-17T12:00:00" + (60 x 60 x 24 x 365 x 5) seconds? No one knows! And the answer to that question will change depending on when you calculate it and which updates you installed! So I say ditch the leap second and let it drift. In a few hundred years we could update our timezones if we _really_ want to (timezone changing is actually pretty common, so code should already be handling this edge-case).