How can I get the Google cache age of any URL or web page?

http://stackoverflow.com/questions/4560400/how-can-i-get-the-google-cache-age-of-any-url-or-web-page

 How can I get the Google cache age of any URL or web page?

Use the URL

http://webcache.googleusercontent.com/search?q=cache:

Example:

http://webcache.googleusercontent.com/search?q=cache:stackoverflow.com

It contains a header like this:

This is Google's cache of http://stackoverflow.com/. It is a snapshot of the page as it appeared on 21 Aug 2012 11:33:38 GMT. The current page could have changed in the meantime. Learn more
Tip: To quickly find your search term on this page, press Ctrl+F or ⌘+F (Mac) and use the find bar.