/**
 * Add custom date formats
 */
Highcharts.dateFormats.W = function (timestamp) {
    var date = new Date(timestamp),
        day = date.getUTCDay() === 0 ? 7 : date.getUTCDay(),
        dayNumber;

    date.setDate(date.getUTCDate() + 4 - day);
    dayNumber = Math.floor((date.getTime() - new Date(date.getUTCFullYear(), 0, 1, -6)) / 86400000);

    return 1 + Math.floor(dayNumber / 7);
};

Highcharts.chart('container', {

    title: {
        text: 'Custom date format'
    },

    xAxis: {
        type: 'datetime',
        tickInterval: 7 * 24 * 36e5, // one week
        labels: {
            format: '{value:Week %W/%Y}',
            align: 'right',
            rotation: -30
        }
    },

    series: [{
        data: [29.9, 71.5, 106.4, 129.2, 144.0, 176.0, 135.6, 148.5, 216.4, 194.1, 95.6, 54.4],
        pointInterval: 7 * 24 * 36e5,
        pointStart: Date.UTC(2013, 0, 7)

    }]

});