How to tell a book's publication from it's copyright date

 New Media Rights, which provides legal services, educational resources, and public policy advocacy for creators, entrepreneurs, and internet users, explains the difference between a book publishing date and book copyright date.  For collectors, a book's copyright page is usually found on the verso of the title page.

... the copyright date that you see on the inside of the book jacket likely coincides with the date of formal registration or the date that the work was finished and submitted to the publisher.

The author of a work has a copyright to the work as soon as it is created. All s/he has to do is “fix the original work in a tangible medium of expression,” meaning either putting pen to paper or just saving a word document. 

An author can either retain their copyright, or assign it to a publishing company.

 (https://www.newmediarights.org/book/copyright_date_same_publication_date)