Ha, amazing, I build the same 24 hour clock with night time for daily planning.

You can use an js SVG animation to have it run in real time: https://tomchen.github.io/animated-svg-clock/clock.svg

I have no idea why we stuck with the 12 hour clocks once we stopped using sundials and variable hours: https://en.wikipedia.org/wiki/Unequal_hours

With your app, it seems daylight today in Chicago is the same length as yesterday's solstice, although it starts and ends 30 seconds later.

today - 07:18:59 → 16:24:29 = 9:5:30. yesterday - 7:18:23 → 16:23:53 = 9:5:30

For a modern equivalent, the first thing that came to my mind was Manhattanhenge:

https://en.wikipedia.org/wiki/Manhattanhenge

Doesn't really work on my setup (0). I am curious if it does more than the PhotoPills app, quite a useful thing for city scapes photography.

0. https://drive.google.com/file/d/1FB3Ofl4mUvOO4gGqARro9cO_kjJ...

/edit: Looks like noscript blocks the p5 thing.

and yes, the maths fails when you are super super high north or south