Query to capture WTParts set to Released in the last 4 hours

I need to report, every 4 hours, the WTParts which were set to Released in that time frame.

I don't think I want the .modifyStamp as shown below. It does not seem to work properly even, as it reports many items which were not Last Modified in that time frame.

Any idea how to report when the Released state was set? and how to report the WTParts which were set to released in the last 4 hours?