Highcharts - Last line point not connected

by Ben Clayton

HTML

<script src="http://code.highcharts.com/highcharts.js"></script>
<script src="http://code.highcharts.com/modules/exporting.js"></script>
<div id="graph-19583" style="min-width: 310px; height: 400px; margin: 0 auto"></div>

JavaScript

$(function () {
    new Highcharts.Chart({
        "xAxis": {
            "startOfWeek": 0,
            "type": "datetime",
            "labels": {
                "tickInterval": 86400000,
                "rotation": 300,
                "formatter": function () {
                    return Highcharts.dateFormat('%Y-%m-%d', this.value)
                }
            }
        },
        "yAxis": {
            "plotLines": [{
                "width": 1,
                "color": "#808080",
                "value": 0
            }],
            "min": 0,
            "title": {
                "text": ""
            }
        },
        "chart": {
            "type": "spline",
            "renderTo": "graph-19583"
        },
        "plotOptions": {
            "spline": {
                "marker": {
                    "enabled": false
                },
                "lineWidth": 2
            }
        },
        "credits": {
            "enabled": false
        },
        "legend": {
            "enabled": true
        },
        "series": [{
            "name": "Codes Entered",
            "data": [
                [Date.UTC(2014, 6, 21), 43],
                [Date.UTC(2014, 6, 22), 21],
                [Date.UTC(2014, 6, 23), 27],
                [Date.UTC(2014, 6, 24), 26],
                [Date.UTC(2014, 6, 25), 28],
                [Date.UTC(2014, 6, 26), 20],
                [Date.UTC(2014, 6, 27), 44],
                [Date.UTC(2014, 6, 28), 27],
                [Date.UTC(2014, 6, 29), 41],
                [Date.UTC(2014, 6, 30), 98],
                [Date.UTC(2014, 6, 31), 99],
                [Date.UTC(2014, 7, 01), 108],
                [Date.UTC(2014, 7, 02), 149],
                [Date.UTC(2014, 7, 03), 151],
                [Date.UTC(2014, 7, 04), 180],
                [Date.UTC(2014, 7, 05), 182],
                [Date.UTC(2014, 7, 06), 180],
                [Date.UTC(2014, 7, 07), 268],
                [Date.UTC(2014, 7, 08), 268],
              ...