Yes, according to Google content freshness can be a positive ranking signal, but only for search queries that require up-to-date, relevant results. Such queries are known as QDF, or “Query Deserves Freshness”, and they can make up to 35% of the total queries, according to Google. QDF queries may include recent events or hot topics, regularly recurring events, or frequent updates. Here’s the official

“today we’re making a significant improvement to our ranking algorithm that impacts roughly 35 percent of searches and better determines when to give you more up-to-date relevant results for these varying degrees of freshness.” source

And here’s another statement from ex-Googler, Matt Cutts:

Q: ”Query deserves freshness. Fact or fiction?”

A: “It’s a fact” source