Hi,
You need to re scan file or only single folder containing that file to MM library, but you will possible need to enable that MM update all metadata on rescan at Tool -> Options -> Library

In the album view page, when you open an album it shows all the tracks and how long they are to the right of them.

https://i.gyazo.com/72241664944ae5d54585358a5504b2cc.png

In this album the first song is 29 seconds. I recently edited the file so that it's 31 seconds. Is there a way to update the entry so that it shows the correct timestamp? Or do I have to manually delete and re-add the file?