I track wait times at the Berlin immigration office. I just added a graph that shows how wait times improve/worsen over time. I generate the SVG without any external dependencies. It was a fun exercise.

https://allaboutberlin.com/guides/immigration-office/wait-ti...

I wish I had more time for such projects, but since AI is now capturing most of the traffic, I am losing a lot of my income and I have to make up for it. It's a huge distraction.

You will probably have to use the BigInt data type to track those wait times.