Found a new use for ChatGPT: ancient code spelunking. I was working on the scale for my minute-by-minute rain graph and I remembered that I'd solved this in Check the Weather. Dug around in its ObjC source code and found the section responsible (which git tells me was written in April 2013).
It involved a complicated formula I didn't recognize or understand. So I asked ChatGPT what it meant and it did a surprisingly good job of giving me a starting point to now go and research again.
