I'm using the PHP SDK for adding reviews/ratings of books. Whenever someone updates the rating of a book or a review on my site, I am sending in an update request through the API for the original open graph id associated with the rating/review and it does update the rating/review values but the timestamp on the action is still set to whenever it was first submitted. I want to have the time be reflected of the last update so it shows up in their activity feed/timeline in the right place.
I've tried modifying end_time,start_time and publish_time based on the documentation here: https://developers.facebook.com/docs/opengraph/using-actions/
but nothing does anything to modify the timestamp of the action. Any ideas?