Do you guys just use math to retime your speedruns down to the milleseconds or do you use programs? If so, which one?

Properly https://noobjsperson.github.io/speedrun-timer if im wrong tell me

Ok. I'd like to add, whats the difference bewteen that one and this one: https://somewes.com/frame-count/ (they have 1 milleseconds of difference when retiming using both of em: yours uses YT vids while this one uses the original file since with yt vids its broken).

They retime the speedrun if you do run in 6 minutes and 6 seconds and its acually 6 minutes and 5 seconds, it will be the fastest one of the 2 times.

So if I need to pick a time out of the 2 I need to pick the fastest time?

but what if you didn't add a timer and just did math but it was wrong