Edit in JSFiddle

$(function () {
    $.getJSON('http://www.highcharts.com/samples/data/jsonp.php?filename=usdeur.json&callback=?', function (data) {

        var lastDate = data[data.length - 1][0],  // Get year of last data point
            days = 24 * 36e5; // Milliseconds in a day

        // Create the chart
        $('#container').highcharts('StockChart', {

            rangeSelector: {
                selected: 1
            },

            title: {
                text: 'General Fund Balance & Liquidity Tracker'
            },

            yAxis: {
                title: {
                    text: 'General Fund Balance'
                }
            },

            series: [{
                name: 'Fund Balance',
                data: data,
                id: 'dataseries',
                tooltip: {
                    valueDecimals: 4
                }
            }, {
                type: 'flags',
                name: 'Flags on series',
                data: [{
                    x: lastDate - 60 * days,
                    title: 'Liquidity: 100 Days Cash on Hand'
                }, {
                    x: lastDate - 30 * days,
                    title: 'Liquidity: 50 Days Cash on Hand'
                }],
                onSeries: 'dataseries',
                shape: 'squarepin'
            }, {
                type: 'flags',
                name: 'Flags on axis',
                data: [{
                    x: lastDate - 45 * days,
                    title: '45 days Prior to FY End'
                }, {
                    x: lastDate - 15 * days,
                    title: '15 days to Fiscal Year End'
                }],
                shape: 'squarepin'
            }]
        });
    });
});

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


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