Neverending "Date" issue
This is a suggestion for a dayforward fix.
The problem is with Calibre's "Date" field. Which date is it "supposed" to be? Is there a canonical answer?
As far as I can tell from practice and review of past threads, it is now thought to default to the date the ebook was added to the particular Calibre library.
However, an entry in an .opf file can override this, so we're back to what is supposed to be its canonical purpose?
The most likely "other" date is, obviously, the publication date.
I suggest clarifying this much by adding a "PubDate" category to Calibre's non-user-defined columns, because this will clarify where the publication date belongs for everyone.
An entry, if any, in an .opf file should update the new PubDate field, since no creator of the .opf file could possibly know what date anyone added the book to their library.
It would be even better if the "Date" column header were changed to "Date Added", but there is probably too much history for that to work.