seriesDefaults.labels.rotation String|Number

The rotation angle of the labels. By default, the labels are not rotated.

 <div id="chart"></div>
    <script>
    $("#chart").kendoChart({
        seriesDefaults: {
          type: "column",
          labels: {
            visible: true,
            rotation: 310
          }
        },
        series: [
           { data: [1, 2, 3] }
         ]
    });
  </script>