Thanks for those responses.

My next question is for Cjards query that worked well.

The question is how do I now limit that result set so that it only returns a result set for those stores who have had category changed between two dates say as weeks worth.

What this means is that the date parameter can only be applied to the very latest updates however we still want to see the history and do not want it filtered out.

Stores that have had their last update made outside of this 'week' should not appear.