Google’s John Mueller addressed the ongoing issues and complaints about how Google displays dates in the search results snippets and how sometimes, maybe more often than anyone wants, the dates in the snippets are wrong. John said most of the time they are not an SEO trick, it is just Google picking up the wrong dates from maybe content in the article, maybe a comment date or something else – but most often, it is not some sort of spam tactic.

Why is it not a spam tactic? Well, having a different date typically doesn’t help the article rank better in organic search. Although, it may impact Google News.

John said at the 27:33 mark in the last webmaster hangout:

This snippet date thing is an ongoing issue for Google, we’ve covered it many times. In fact, sometimes it shows the impossible and sometimes people do trick Google but the signals Google uses for picking up dates is not perfect and it is an ongoing project for them.

Forum discussion at Twitter.