var headcount = [ {date: "1/2009", dept: "eng", type: "perm", headcount: 140}, {date: "1/2009", dept: "eng", type: "temp", headcount: 39}, {date: "1/2009", dept: "sales", type: "perm", headcount: 209}, {date: "1/2009", dept: "sales", type: "temp", headcount: 123}, {date: "4/2009", dept: "eng", type: "perm", headcount: 160}, {date: "4/2009", dept: "eng", type: "temp", headcount: 44}, {date: "4/2009", dept: "sales", type: "perm", headcount: 229}, {date: "4/2009", dept: "sales", type: "temp", headcount: 113}, {date: "7/2009", dept: "eng", type: "perm", headcount: 174}, {date: "7/2009", dept: "eng", type: "temp", headcount: 41}, {date: "7/2009", dept: "sales", type: "perm", headcount: 224}, {date: "7/2009", dept: "sales", type: "temp", headcount: 169}, {date: "10/2009", dept: "eng", type: "perm", headcount: 190}, {date: "10/2009", dept: "eng", type: "temp", headcount: 43}, {date: "10/2009", dept: "sales", type: "perm", headcount: 232}, {date: "10/2009", dept: "sales", type: "temp", headcount: 185} ]; (function() { var df = pv.Format.date("%m/%y"); headcount.forEach(function(d) { d.date = df.parse(d.date); }); })();