Google Cache Showing Last Retrieve Dates in Minutes at Search Engine Roundtable shows how Google is now showing when it last visited some pages on a per minute or per hour basis, rather than in the traditional per day style.
For example, this is how Google has normally shown last visit dates for some pages:
Now some pages are getting a time stamp showing they were last visited within minutes or hours, rather than days:
You should be able to reproduce this yourself by going to http://126.96.36.199/ and searching for some news sites that Google is known to spider on a frequent basis, such as the BBC, CNN, and so on. Here’s an example for the BBC: site:bbc.co.uk. Postscript From Danny: My Squeezing The Search Loaf: Finding Search Engine Freshness & Crawl Dates article from last February covers how the various search engines show dates for when they last visited a page, whether it be on the search results page, on cached pages or through webmaster tools. At that time, Google was being inconsistent in how it showed dates for some pages and never provided an official, on-the-record explanation. Now it seems likely they’re trying to be more consistent and, in fact, may announce how they hit some pages within minutes. As Barry said, we’re checking on this.
Postscript From Barry: Here is a response from Google:
We are always working on innovative ways to improve our index and provide users with relevant information. What you are seeing is an experiment that we are currently testing. We run between 50-200 search experiments at any given time and based on user feedback, we may or may not develop new features and products. For more information on our live experiments, please visit http://googleblog.blogspot.com/2006/04/this-is-test-this-is-only-test.html.