Nice experiment.

Some feedback:

I could not catch that the circle meant the sun. I did catch seconds, minutes, day, month, and I deduced TK meant Tokyo and SF meant San Francisco and could not deduce the city ZG represents. So, I don' think you can actually be free of baggage. Some minor things bugging me: - The lines at the bottom don't align! Really annoying, I spent a lot of time trying to understand it meant something or not. - Dark mode shows only 1 city. I could not understand what TK meant until I saw SF.

Some advice:

- Change the pictoric representation of the sun for something a bit more "sunny". Some flames feel like something not cultural (since there literally is solar activity at the surface), so aliens could get that it is the sun. - In the intro you say there is a puzzle, but you don't say what the puzzle is. I thought it might be some interactive thing. It was only until I gave up I start reading the explanation and got that the puzzle is to understand how the clock works, given it has no cultural baggage. Then I went back to try to understand it. Maybe add a little explanation somewhere saying the intention.