Answers for "var json=$.parseJSON(data);"

json_decode jquery

var obj = jQuery.parseJSON( '{ "name": "John" }' );
alert( obj.name === "John" );

json to array javascript

var json_data = {"2013-01-21":1,"2013-01-22":7};
var result = [];

for(var i in json_data)
    result.push([i, json_data [i]]);


var data = new google.visualization.DataTable();
data.addColumn('string', 'Topping');
data.addColumn('number', 'Slices');
data.addRows(result);