title: Chart of chart.js can't display In Edge and Firefox
body: <p>I have a chartjs script, It can run in chorme and show the data of comparsion of 2 periods. But I run it with  Edge or Firefox , it only shows the frame of chart without data and no error message. I want to have my chart look like the samlpe of <a href="https://www.chartjs.org/samples/latest/charts/bar/vertical.html" rel="nofollow noreferrer">https://www.chartjs.org/samples/latest/charts/bar/vertical.html</a>. What's wrong with my code ? Anyone can help me,
  Thanks!
  My script is as below :</p>
  
  <pre><code>&lt;!doctype html&gt;
  &lt;html&gt;
  &lt;head&gt;
      &lt;title&gt;Bar Chart&lt;/title&gt;
      &lt;script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.9.3/Chart.bundle.min.js"&gt;&lt;/script&gt;
      &lt;style&gt;
          canvas {
              -moz-user-select: none;
              -webkit-user-select: none;
              -ms-user-select: none;
          }
      &lt;/style&gt;
  &lt;/head&gt;
  
  &lt;body&gt;
  &lt;div style="width:75%;"&gt;
      &lt;canvas id="canvas"&gt;&lt;/canvas&gt;
  &lt;/div&gt;
  &lt;script&gt;
  
      var config = {
          type:    'bar',
          data:    {
              datasets: [
                  {label: "Year: 2019 " ,
    data: [{ x: "01", y: 100 },
           { x: "02", y: 175 },
           { x: "03", y: 178 },
           { x: "04", y: 300 }],
                      fill: false,
                      borderColor: 'blue',
                      backgroundColor: 'blue'},
  
    {label: "Year: 2020 "  ,
    data: [{ x: "01", y: 120 },
           { x: "02", y: 145 },
           { x: "03", y: 158 },
           { x: "04", y: 200 }],
                      fill: false,
                      borderColor: 'green',
                      backgroundColor: 'green'},
              ]
          },
          options: {
              responsive: true,
              title:      {
                  display: true,
                  text:    "Comparsion of 2 periods"
              },
              scales:     {
                  xAxes: [{
                      type:       "time",
                      time:       {
                          unit: 'month',
                          displayFormats: {
                                            month: 'MMM'}
                      },
                      offset: true,
                      scaleLabel: {
                          display:     true,
                          labelString: 'Time'
                      }
                  }],
                  yAxes: [{
                      scaleLabel: {
                          display:     true,
                          labelString: 'Consumption'
  
                      },
                      ticks: {
                         beginAtZero : true
                         }
                  }]
              }
          }
      };
  
      window.onload = function () {
          var ctx       = document.getElementById("canvas").getContext("2d");
          window.myLine = new Chart(ctx, config);
      };
  
  &lt;/script&gt;
  
  &lt;/body&gt;
  
  &lt;/html&gt;
  </code></pre>