The truthful answer is we don’t know your data, so we can’t comment on why you got what you’re seeing. Only you know your data well enough in order to determine validity. After reading your posting a question in mind is why you are not using the “between” operator. Keep in mind that between is conclusive, so if you say [Posting Month Year] between 2007/9 and 2008/9 then all records that have a September 2007 thru September 2008 date will be included. If you need more help with this concept please post the application you are using (Designer, WebI, etc) and workflow you are applying to get your results.