While a date in the URL may provide a signal of relevancy to some searchers looking for archived information, many people who are explicitly looking for old information will likely put a date in their search query, which will match page text even if the date is not in the URL. Other searchers have a good possibility of rediscovering the information they read in the past with the help of search personalization algorithms. But most queries are not for old stuff. And that makes me believe that using the date in the URL causes more harm than good.
Dates convey irrelevant information
If your file structure uses dates as folders in the URLs, that puts low relevancy data (the date) before the more relevant category name and individual file name. If your keywords are in your filename they may be bolded by the search engine, which would make your URL appear more relevant to searchers. Just like with the page title, I believe the earlier you have highly relevant data in the filename, the easier it will be for it to stick out to a searcher scanning the search results.
Dates suggest old, stale news
While your year-old content may be fresher than anything else ranking at the top of Google’s search result, if you are the only one who places a date in your URL people may think your content is old and stale, especially since Google puts fresh cache dates in many search results. This could also result in a lower click through rate.
Dates make sharing URLs more difficult
Using dates in the URL makes your file paths longer, which makes links sent in email more likely to break. Some social media sites, like StumbleUpon, only show the first 25 characters of a URL on their site. If those characters are wasted on dates, the file many not appear as relevant as if those characters contained the category name or file name.
Dates can cause robots.txt errors
If you find that you would prefer to keep category and individual post pages indexed but you want to filter out monthly archives, it is easy to accidentally block some of your other content pages if they have the dates in the URLs as well. One mistake I made doing something similar cost me in excess of $10,000.
Opinions expressed in the article are those of the guest author and not necessarily Search Engine Land.