The day starts at zero, not 12. 12 is “Noon” ie halfway through the day. The clock starts at 12 because it’s more practical than inscribing 24 divisions in a circle. And the 6 doesn’t “mean 30”, it’s simply the hour marking at the bottom of the circle. Finally, the 12 hour clock was invented after the 24 hour day, not the other way around.
And inb4 “I bet you’re fun at parties”. I’m all for “this logic is ridiculous” jabs, but this is just misrepresenting everything to make it sound stupid. Everything sounds stupid when you purposefully get it wrong.
Personally, I enjoy this kind of discussion at parties.
It’s a lot of different things it’s design is based on the sundial, we already had base 12 time
Wikipedia page for base 12, the origin is a fun read and while I can’t say it’s all accurate, the parts I know are