I selected order by AttributeKey and wan

Written by OrderBy doesn't list attributes. Posted in Comments

I selected order by AttributeKey and wanted to change the Month Year to order by Month Year Key, but no attributes appears in the Order by list. the Month Year orders by Alpha ie. apr2008, apr2009, may2008,may2009. I wanted it to order Month Year Key ie. apr2008, may2008, jun2008 etc.