The Milliseconds Data Is Not Present In The History Data Of Highcharts

The issue is that when there is a huge data in historyData of highcharts,then on zooming in the data is present only for every second and not for milliseconds. So on zooming in for

Solution 1:

The difference is that your initial data has a one-second interval:

for (i = -999; i <= 0; i += 1) {
    data.push([
        time + i * 1000,    // date every secondMath.round(Math.random() * 100)
    ]);
}

The data that is dynamically added has a 20 milliseconds interval:

setInterval(function() {
    var x = (newDate()).getTime(), // date every 20 milliseconds
        y = Math.round(Math.random() * 50);
    series2.addPoint([x, y], true, true);
}, 20);