mm-dd-yyyy doesnt work for me?

can u please tell me what I am doing wrong here?

<script>

var awdata = [
["1","1000","Aragon","Luis","01-25-2006","New Order"],["4","1001","Aragon","Luis","02-02-2003","New Order"],["5","1002","Aragon","Luis","12-15-2005","New Order"],["6","1003","Aragon","Luis","02-12-2006","New Order"],["7","1004","Aragon","Luis","02-15-2006","New Order"],["8","1005","Aragon","Luis","02-15-2006","New Order"],
];

var awheaders = ["Order ID","Order No.","Last Name","First Name","Date","Status"];

var obj = new AW.UI.Grid;
obj.setId("awgrid");

var str = new AW.Formats.String;
var num = new AW.Formats.Number;
var dte = new AW.Formats.Date;

dte.setDataFormat("mm-dd-yyyy");

obj.setCellFormat([str, str, num, dte, num]);
obj.setHeaderText(awheaders);
obj.setColumnCount(6);
obj.setColumnIndices([1,2,3,4,5]);
obj.setCellText(awdata);
obj.setRowCount(6);
obj.setSelectionMode("single-row");

nm, forgot to add a column to the setCellFormat.