SUGGESTION: Count the lengths of files with accordance to reality

Possibly, I used wav files.

Edit / update:

I converted the files in my previous post to compare file formats. For the nearly 3-second files, FLAC and mp3 (cbr & vbr) formats were rounded off upwards but the wav files were rounded off downwards in Mp3tag. In Foobar though, all file formats were rounded off upwards.

A bit interesting, but nothing I would worry about.