Originally Posted by kovidgoyal
The date incompatibility is because of a bug in epubcheck not calibre. Incidentally, Adobe InDesign will also give you epubs that dont pass the iBookStore validation process.
Basically, iBookStore needs to fix its validation process either by fixing epubcheck or ignoring some of epubchecks erroneous errors.
Looking at iTunes Connect (for iBioikstore publishers) today, I see this statement in the FAQ:
"Note that some tools do not create valid EPUBs. We therefore strongly recommend against using Calibre. "
I assume that Apple is talking about the output of calibre's conversion routines of which there are several.
Or is this simply about the date bug in ePub check?