Jquery flot plugin is not plotting graph according to the date

I'm trying to plot a graph using jquery flot plugin with JSON data. What I need to do is.

• When the page loads it will makes an ajax call and receives json data from the server.
• from the received json I need to add 'x' and 'y' axis label. And I want to draw the graph
• according to points in json data.
• 'Y' axis must have values from 0 to 100
• 'X' axis should have only json data value

My Script is:

    //var maxDate = new Date();
    //var minDate = new Date();
    var options = {
        series: {
            lines: {
                show: true
            },
            points: {
                show: true
            }
        },
        grid: {
            hoverable: true,
            clickable: true
        },
        xaxis: { //min: minDate.setMonth(maxDate.getMonth() - 12),
                //max: maxDate,
                mode: "time",
                monthNames: ["January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"],
                timeformat: "%b(%Y)" 
        },
        yaxis: {
            min: 0,
            max: 100,
            ticks: 10
        }
    var data = [];
    var placeholder = $("#trigo");

        var dataurl = 'cprogress.php?action=overall';

        // then fetch the data with jQuery
        function onDataReceived(series) {
            data.push(series);
            $.plot(placeholder, data, options);
            setData(data);
         }

        $.ajax({
            url: dataurl,
            method: 'GET',
            dataType: 'json',
            success: onDataReceived
        });

Now my graph Looks like this

And the JSON

[["2013-11-05",8.3333333333333],["2013-12-05",0]]

What I want to print is November(2013) and December(2013) and have to draw graph from 8.33 to 0 Now it is print January(1970) Why I don't know.

Please any one help me to solve this issue. I'm struggling to solve this from two days. Thanks...