Originally Posted by AaronM

One very easy solution.

http://bluecowhosting.com/blog/wordp...on-seo-plugin/

It has an option to set an expiration for the post date based on any given number of days. In my case, I set it for 14 days and after those two weeks, the post date is automatically removed. It does the same to all posts that are already older than 14 days.