[BetterRed]

@bodiccea - a books last_modified column will be updated whenever you change any column that affects a book, but what's not obvious is that a modification in one book, say the spelling of a tag, can ripple through many books.

I found that the rippling changes were almost invariably caused by corrections to my errors, so I gave up on trying to make any use of the last_modified column. Instead I maintain a custom column - '#last-change'. This is pretty easy for me because I do all my metadata editing in the book list. So, I just tab into the cell and press '=', to set it to 'now'. If it's an error correction I don't update '#last_change'.

And, if I change the content of a book I can update '#last_change', IIRC changing the content of a book with an editor does not update 'last-modified'. The vast majority of my books are not commercial publications, so I do a lot of content editing.

BR