Highchart - datetime

Highcharts uses 1970 when date is null !

by Ben Clayton

HTML

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

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

JavaScript

$(function () {
    Highcharts.chart('container', {
        chart: {
            type: 'spline'
        },
        title: {
            text: 'Snow depth at Vikjafjellet, Norway'
        },
        subtitle: {
            text: 'Irregular time data in Highcharts JS'
        },
        xAxis: {
            type: 'datetime',
            
            title: {
                text: 'Date'
            }
        },
        yAxis: {
            title: {
                text: 'Snow depth (m)'
            },
            min: 0
        },
        tooltip: {
            headerFormat: '<b>{series.name}</b><br>',
            pointFormat: '{point.x:%e. %b}: {point.y:.2f} m'
        },

        plotOptions: {
            spline: {
                marker: {
                    enabled: true
                }
            }
        },

        series: [{
            name: 'Winter a',
            data: [
                [null, 2],
                [Date.UTC(2015, 1, 21), 0],
                [Date.UTC(2015, 9, 28), 1]
            ]
        }, {
            name: 'Winter b',
            data: [
                [Date.UTC(2015, 8, 21), 0],
                [Date.UTC(2015, 9, 27), 1.3]
           ]
        }, {
            name: 'Winter c',
            data: [
                [Date.UTC(2015, 9, 21), 0.4],
                [Date.UTC(2015, 11, 25), 1.4]
           ]
        }]
    });
});