FFF populates:
- Calibre's standard Date column (aka timestamp) with FFF's Packaged datetime (aka dateCreated), and;
- Calibre 's standard Published column (aka pubdate) with FFF's Published date (aka datePublished).
If you want a column specifically for FFF's Updated (aka
dateUpdated) metadata, you need to add a custom column for it. That's one of the custom columns I use, too.
That decision dates back to the
prior incarnation of the plugin when it was called FanFictionDownLoader.
(Note that Calibre's Modified column (aka
last_modified) is automatically set by Calibre on any change.)