title: Export data from highcharts in csv file with dates in milliseconds
body: <p>I have an angularjs application with the library Highcharts.</p>
  
  <p>In my application I have some graphs and want to export the data of the graphs in a CSV file. So I used the exporting function from highcharts but I have a problem with the dates. On my graphs, I display the dates with a format "MM/DD/YYYY hh:mm:ss" so when I export my data, I have the same format but I would have the dates in milliseconds. I try to change teh 'dateFormat' field in the exporting options but milliseconds is not part of the accepted formats.</p>
  
  <p>This is my graph options:</p>
  
  <pre><code>widgetCtrl.chartDataLine = {
      chart: {
          type: 'spline',
          zoomType: 'x',
          isZoomed: false,
          marginTop:55
      },
      title: {
          text: 'title',
          align:'left',
          x: 20,
          y: 18,
          style: {
              fontSize: '14px'
          }
      },
      xAxis: {
          type: 'datetime',
          title: {
              text: 'Date time'
          }
      },
      yAxis: {
          title: {
              text: 'Power (W)'
          }
      },
      boost: {
          enabled: true
      },
      exporting: {
          fallbackToExportServer: false,
          enabled: true,
          allowHTML: true,
          filename: 'myFile',
          menuItemDefinitions: {
              downloadJSON: {
                  onclick: function () {
                      downloadJSON('myFile.JSON', widgetCtrl.chartDataLine.series);
                  },
                  text: 'Download JSON'
              }
          },
          csv: {
              decimalPoint: '.',
              dateFormat: '%Y-%m-%d %H:%M:%S'
          },
          buttons: {
              contextButton: {
                  menuItems: [
                      'printChart',
                      'downloadPNG',
                      'downloadJPEG',
                      'downloadPDF',
                      'downloadSVG',
                      'downloadCSV',
                      'downloadJSON'
                  ]
              }
          }
      },
      navigation: {
          buttonOptions: {
              align: 'left'
          }
      }
      series: [...]
  };
  </code></pre>
  
  <p>Do you have an idea how I coul do that without writing myself teh csv file but using the highcharts functions ?</p>