Published comes from Metadata.
It could be within the book (initial entry in Calibre)
or Later downloaded (updated in Calibre)
This may be Site dependent (somewhat depending on how many Metadata Source PI are configured). If the same site supplies the Pubdate, there may be a scraping problem due to a site change. Yo need to figure where the wrong data comes from.
1) If it is bad in the book ++>Blame the Publisher
2) If it turns out all those WERE Apr2014 ++> Blame the Purchaser
