Import Date: Bug or Feature?

[Starson17]

Originally Posted by dwanthny

That's the confusing part, until you run into a book you're adding that has the date field set in it all you've seen was today's date. But all of a sudden you got a copy of some PD epub from a friend, add it to calibre, and expect it to have today's date like the last 840 books you added but it places the date from the epub's metadata and poof "the date has shifted".

Aha! I was thinking that the date was set at some desired value, then changed to something else. I can see it would be confusing if you added a book and didn't see today's date when you added it, if that's all you'd ever seen. I almost never allow Calibre to use internal book metadata during an Add.

It seems to be really bad most of the time. Since I have "Get metadata only from filename" almost always turned on, I never get the internal metadata date, even if it's there. If I'm adding lots of books, I always have the "Get metadata only from filename" turned on, and I check the filename (and the Add regex) to ensure a good title/author. If I'm adding a single book, I just check all the metadata, or, more often, leave "Get metadata only from filename" turned on, then single edit metadata and use the internal button that extracts metadata from a specified format. I can watch it and check for any errors, including the date metadata error.

[kovidgoyal]

Just to clarify: calibre uses a custom field in EPUB files for the calibre date. The reason for that is simple. I want people to be able to save to disk and re-add and not lose the date information.

Since it is a custom field, no book that has not come from calibre will have it. SO if you get a book from a friends calibre install, the date will probably be set in the book. But if you download the book from say Project Gutenberg, it wont.

[DoctorOhh]

Originally Posted by kovidgoyal

Just to clarify: calibre uses a custom field in EPUB files for the calibre date. The reason for that is simple. I want people to be able to save to disk and re-add and not lose the date information.

Thanks for the clarification, makes complete sense now.

[Starson17]

Originally Posted by kovidgoyal

Just to clarify: calibre uses a custom field in EPUB files for the calibre date.

Thanks. I can see my answer above was incorrect. For reasons I won't go into, when I checked a saved EPUB before answering, there was no custom field for Calibre's date, so I incorrectly assumed it was the non-custom date field.

Here is the content of a Saved to Disk .opf file:

        <dc:date>1986-12-31T05:00:00+00:00</dc:date>
        <meta content="2009-12-30T05:00:00+00:00" name="calibre:timestamp"/>

The first is the non-custom date field ("Published" in Calibre) and the second is the custom date field ("Date" in Calibre).

The content.opf file inside an EPUB is essentially the same.

[kovidgoyal]

yes published maps to dc:date and date maps to the custom field