Hi,
While cleaning up the books in my library, I've found something strange.
When I put a publication date into a book using Sigil, it looks like this:
Code:
<dc:date opf:event="publication">2005-01-01</dc:date>
This is fine: when importing a book into Calibre, it sees the publication date and displays it accordingly. (There is also a "<dc:date opf:event="modification"></dc:date>, which Calibre does not seem to use.)
After updating metadata, either through Modify EPUB, Polish Books, or Save to Disk, the publication date looks like this:
Code:
<dc:date>2004-12-31T23:00:00+00:00</dc:date>
In one way or another, it seems Calibre is able to import this book again, and still display the publication date as being 2005.
If the book is then edited again with Sigil, Sigil doesn't see the publication date anymore. It doesn't show in the tag editor. Often, but not always (strangely enough), Sigil actually deletes the <dc:date> part from the OPF-file.
If the book is then imported into Calibre again, the publication date is gone.
As this problem occurs with Save to Disk, Polish Books and Modify EPUB, I expect this problem to be in the Calibre API. I think I'd be best if Calibre saved the publication date in the same way as Sigil, if at all possible, when updating metadata.
(In case you ask: I'm very particular about my EPUB files being as perfect as possible, with correct tags, dates, a high resolution cover, my preferred layout, and so on. I store a copy of all of my "perfected and finished" books outside Calibre. I use both a "workplace library" and Sigil in conjuction to make the ebooks as I want them.)