How do you figure out the miliseconds when submitting a run? I want to figure this out for my next run. I got 1:57:25.60 on my first one for example. Is that 60 or 600? I'm not too sure how miliseconds work in general.

We use

https://amineelbaghdadi.me/speedrun-timer/index.html

to time our runs. This website times runs based on frames. If a video is 60 fps, each frame is 16 milliseconds (60 frames per second, 1/60 = 0.016 seconds per frame)

If anything, you wrote the same thing, because 0.6 = 0.60 = 0.600. These are the simplest decimal numbers...