Demo of the problem with column chart as stackedColumn chart

Basic Column Chart - CanvasJS JavaScript Charts

by canvasjs

HTML

<script src="http://canvasjs.com/assets/script/canvasjs.min.js"></script>
<br/><!-- Just so that JSFiddle's Result label doesn't overlap the Chart -->
<div id="chartContainer" style="height: 360px; width: 100%;"></div>

JavaScript

var chart = new CanvasJS.Chart("chartContainer",{        
  data: [
    {
      type: "stackedColumn",
      dataPoints: [
        {x: new Date("2017-03-10"), y:600},
        {x: new Date("2017-04-06"), y:504},	//<--first column in April
        {x: new Date("2017-04-06"), y:600},	//<--second column in April should be stacked!
        {x: new Date("2017-05-03"), y:504},
        {x: new Date("2017-05-03"), y:504},
        {x: new Date("2017-06-05"), y:504},
        {x: new Date("2017-08-07"), y:714},
        {x: new Date("2017-09-04"), y:714},
        {x: new Date("2017-10-02"), y:504},
        {x: new Date("2017-11-06"), y:504},
        {x: new Date("2017-12-04"), y:540}
      ]
    }					
  ]
});

chart.render();