I am currently using Excel 2007 i have 1 work book with 8 sheets and have created 1 overall sheet that i merged all 8 sheets i have entered the autofilter tab on the top columns of the overall sheet created when i select sort by oldest date to newest date it doesn't filter all dates i have checked the date formats ensured that the entire column has the correct date format? some sheets were created using Excel 2003, but used 2007 to create the overall sheet, can someone provide me a solution?