Highcharts Datetime x axis (points by interval)

The data is done with a start date a time interval, and then just all the Y values.

HTML

<script src="http://code.highcharts.com/highcharts.js"></script>
<script src="http://code.highcharts.com/modules/exporting.js"></script>

<div id="container" style="min-width: 310px; height: 400px; margin: 0 auto"></div>

JavaScript

var graph;

$(function () {
    graph= new Highcharts.Chart({
        chart: {
            zoomType: 'x',
            renderTo:'container'
        },
        title: {
            text: 'USD to EUR exchange rate from 2006 through 2008'
        },
        subtitle: {
            text: document.ontouchstart === undefined ?
                    'Click and drag in the plot area to zoom in' :
                    'Pinch the chart to zoom in'
        },
        xAxis: {
            type: 'datetime',
            tickInterval: 40000,
            minRange: 1000 * 60 // fourteen days
        },
        yAxis: {
            title: {
                text: 'Exchange rate'
            }
        },
        legend: {
            enabled: false
        },
        plotOptions: {
            area: {
                fillColor: {
                    linearGradient: { x1: 0, y1: 0, x2: 0, y2: 1},
                    stops: [
                        [0, Highcharts.getOptions().colors[0]],
                        [1, Highcharts.Color(Highcharts.getOptions().colors[0]).setOpacity(0).get('rgba')]
                    ]
                },
                marker: {
                    radius: 2
                },
                lineWidth: 1,
                states: {
                    hover: {
                        lineWidth: 1
                    }
                },
                threshold: null
            }
        },

        series: [{
            type: 'area',
            name: 'USD to EUR',
            pointInterval:  1000,
            pointStart: Date.UTC(2006, 0, 1),
            data: [
                0.8446, 0.8445, 0.8444, 0.8451,    0.8418, 0.8264,    0.8258, 0.8232,    0.8233, 0.8258,
                0.8283, 0.8278, 0.8256, 0.8292,    0.8239, 0.8239,    0.8245, 0.8265,    0.8261, 0.8269,
                0.8273, 0.8244, 0.8244, 0.8172,    0.8139, 0.8146,    0.8164, 0.82,    0.8269, 0.8269,
                0.8269, 0.8258, 0.8247, 0.8286,    0.8289, 0.8316,    0.832, 0.8333, ...