I'm on Xbox and I have no idea how I can get milliseconds for one of my times.

Your best bet is to upload the time in seconds then just set the milliseconds to 000. Because usually mods have to do a mod re-time anyways. I don't use xbox, sorry if i wasn't too much help.

We do re-times using this website: https://github.com/slashinfty/yt-frame-timer
Everyone is free to use it.