categoryAxis.rangeLabels.border.width Number (default: 0)

The width of the border in pixels. By default the border width is set to zero which means that the border will not appear.

Example - set the category axis date range label border width

<div id="chart"></div>
<script>
$("#chart").kendoChart({
  categoryAxis: {
    type: "date",
    justified: true,
    baseUnit: "days",
    rangeLabels: {
      format: "d",
      border: {
        color: "green",
        dashType: "dashDot",
        width: 1
      },
      visible: true
    },
    labels: {
      format: "M-d"
    }
  },
  series: [{
    type: 'line',
    field: 'value',
    categoryField: 'date',
    data: [{
      value: 1,
      date: new Date("2012/01/01")
    }, {
      value: 2,
      date: new Date("2012/01/04")
    }, {
      value: 3,
      date: new Date("2012/01/07")
    }]
  }]
});
</script>