[makeitdouble]

The part that's really weird to me is those lines are latitude based, so Finland and South Africa share the same timezone.

Sun wise, situations are a pretty different at any moment in the two countries. I wouldn't call the system "reliable" ( and those are not outliers, any zone with countries on opposite hemispheres has the same issue)

[rypskar]

>>Sun wise, situations are a pretty different at any moment in the two countries

The sun is still at its high point at the same time of the day in both countries

[brightlancer]

> The sun is still at its high point at the same time of the day in both countries

No.

Helsinki's solar noon is about 35 minutes later than Cape Town's and 100 minutes later than Pretoria's.

This is normal, because time zones are mostly broken into non-uniform 1 hour increments across 180 degrees of latitude.

[garrickvanburen]

yep - timezones are not straight lines - namely around the international date line.

[makeitdouble]

Doesn't that presume the earth is perfectly turning around its North/South axis ?

[mixmastamyk]

How would a rock spin other than "perfectly?"

[makeitdouble]

It was more about the spin axis: timezones are vertically cut on a South/North line, while the earth rotation deviates from there.

I actually couldn't find how much it deviates. I assume there's variation depending on the seasons as well.

[mixmastamyk]

Not really, there’s a tiny bit of wobble but it moves over a thousands years or so, nothing to worry about. The axis doesn't change to my knowledge.

https://en.m.wikipedia.org/wiki/Axial_precession

Magnetic poles changing is not relevant it seems.

[makeitdouble]

Thanks, that I didn't know.

I'm kinda glad I tried to explain this, because I realize just how much I lack the proper words for it.

The earth rotation wobbles a bit, but the axis itself is also not tilted towards the sun (it has no specific reason to) nor tilted towards the inside of the revolution axis relative to the sun.

Basically the earth can be spinning on itself around any axis (let's call it A), while revolving around the sun on an unrelated axis (B). And neither A nor B has to be following the North/South axis. That's where the idea that a latitudinal timezone sees a similar solar cycle seems at odds to me.

If an image can help more, the earth's self rotation and sun revolution in this video are clearly not aligned, nor any of them follow the North/South axis: https://www.britannica.com/video/151528/Earth-rotation-axis-...