Publication date is the eighth core element. Whether the year, month and year, or complete date is cited depends on the information available, the type of source, and the use of the source.
Book:
DiYanni, Robert, editor. Literature: Reading Fiction, Poetry, and Drama. 6th ed., McGraw Hill, 2007.
Journal, magazine, or newspaper article:
Dickman, Kylie. "Apocalypse in the Garden State." Rolling Stone, no. 1260, 5 May 2016, pp. 36-9.
Magazine article from a Web site:
Garber, Megan. "The Trump Campaign Just Became Literature." The Atlantic, 28 June 2016, www.theatlantic.com/entertainment/archive/2016/06/the-trump-campaign-just-became-literature/489140/.
Television series episode:
"Something Nice Back Home." Lost, directed by Stephen Williams, performance by Matthew Fox, season 4, episode 10, Bad Robot, 2008.
or
"Something Nice Back Home." Lost, directed by Stephen Williams, performance by Matthew Fox, season 4, episode 10, American Broadcasting, 1 May 2008.
Online video:
"The H Bomb: Making up for Lost Time: Lost." YouTube, uploaded by ABC's Lost, 24 Nov. 2009, www.youtube.com/watch?v=ueh4yEcjCp4.