Most articles or blog posts have a post date or publication date, a date listed on the page such as "Apr 15, 2011 - 2:05 pm" stating the time which the original content was first posted. It's a helpful signal for users to identify how timely and relevant an article is. But how useful is that date to Google's algorithm? Is it helpful or used at all (for ranking in a QDF query for example)? Does Google use it in addition to other factors just as date of page last modified, discovery date/first crawled, etc..?
It's very unlikely and could be a result of many things such as content attribution and his content not being as unique as he believes. Tedster agrees as well saying:
I doubt that the dates are a big factor here... I know that we have a lot of threads about Panda to stay up with, but the summary is that Panda did NOT lower rankings based on any single factor. instead it is a mix of factors, not all of which are currently identified.
Among those who are studying the actual data, no one has found even a low level correlation between dates and lowered rankings.
No correlation observed yet. It's not to say that is not possible however. Finally, forum member Goodroi has some good points worth mentioning. He says:
"I have seen manipulating the dates to be more recent leads to a higher CTR. A higher CTR could possibly help with rankings but I wouldn't blame old dates for ranking problems. "
Continued forum discussion on WebmasterWorld