Custom iTunes:Genre > iBooks:Category

[kidpixo]

Hi everybody,
I searched a lot, but I found no ideas to solve this.

My problem is simple: how to organize my ebook from calibre in ibook on iPad?

1. A natural solution seems to work on the "Collection", but from here
http://discussions.apple.com/thread.jspa?threadID=2670986
I get that there is non tag I can set up in itunes to change it.
It means to me the also in Calibre is not possible to manipulate Ibook "Collection" field, since calibre could just modify some metadata when he send the book to itunes. Am I wrong?

2. I'm almost using only epub form calibre recipes, so I want at least set the Genre in Itunes as the current Date. I can sort the book in iBook as Category (Genre in Itunes), but as I understood from here :

Under the hood
When downloading calibre recipes, the driver changes the metadata before sending the book to iTunes. For example, if you download the NYTimes, the title will be shown as 'The New York Times', and the author will be shown as today's date, e.g. 'Friday, June 18, 2010'. Title sort is 'New York Times', author sort is 'New York Times 2010-06-18'. Periodicals are tagged with 'News' by default, which becomes the Category for the book in iBooks.

I tried to deactivate the Apple plugin, set up a plugboard like
epub:APPLE = ([{Date}] -> tags)
but it never worked, cause the first tas is always set to "News". First of all, makes this idea any sense?