The new Publication date sorting option is ‘interesting’, as the date is not displayed directly anywhere: you have to to See in Store to see what it is, and some titles do not have a Publication date, or have weird dates. For example:
Buddha: With Bonus Material by Deepak Chopra. It has a publication date of December 31, 2075. Given the size of my library, that’s probably about when I’ll get around to reading it.
You would think this would float to the top of the list, but apparently the software ignores future dates and puts them at the end where the ‘no publication date’ books are.
Homage To Catalonia by George Orwell has a publishing date of October 22, 1969. I’m guessing it’s the publication date of the print edition that the digital is based on.
So I’m not sure how useful this is (I’m guessing it is up to the publisher to supply whatever date they want to assign), but it’s there.
But since this piece of metadata must be on device to use for sorting, they should display it somewhere (e.g. when you tap the triple dot icon for the book to see options and details).