Google snippets bug shows old dates based on YouTube embeds
This Google bug shows a date that is older than your blog post in the search results snippet. This doesn't seem to impact rankings directly.
There is a new bug in the Google search results that seems to be impacting web pages that contain YouTube embeds. Instead of showing the date of the page or article, which is published by the author, Google is showing the date of the video embed, pulled from the upload date.
To illustrate the bug, do a search for [understanding google panda] and look for the result from www.thesempost.com. You will see Google dates it as December 30, 2014, but if you look at the page itself, it is dated January 11, 2016.
Here is a screen shot of the date on the story:
If you look at the snippet, this is the date on that:
Google has been aware of the issue for about two days, and there is no ETA for a fix. Some webmasters and site owners believe their rankings may be hurt by this bug, but that does seem unlikely.
Postscript: On November 17th, Google fixed this bug.