Highcharts datetime axis, how to disable time part (show only dates)?

You can intercept the x-axis label function and change it's output. In my example, I've changed it to render short dates:

http://jsfiddle.net/uaxZP/3/

{ xAxis: 
    labels: {
        formatter: function() {
             return Highcharts.dateFormat("%b %e", this.value);
        }
    }
}

        

The xAxis.labels.formatter property allows control over this. You also may notice I'm using Highcharts.dateFormat, which is a utility function for rendering dates. This is not mandatory, but it's a nice built in feature. Documentation on the xAxis formatter is here:

http://www.highcharts.com/ref/#xAxis-labels--formatter

The easiest way to do is using "minTickInterval"

xAxis: {
       minTickInterval: 24 * 3600 * 1000
}

http://api.highcharts.com/highcharts#xAxis.minTickInterval