I want to run an update script on pages that haven't been viewed and updated within X days. I'm using post meta to cache some related RSS feed data, and I want it updated once a week or two, but only if the page has actually been viewed within the last two or three weeks, bots included.
Is there an internal counter or whatnot that has this data, or am I going to have to build something that stores the UNIX timestamp as post meta upon page view?