title: Plot Highchart multiple series line chart using JSON data
body: <p>I tried to plot JSON data using JSON data.<a href="http://jsfiddle.net/Wreck/votky05e/27/" rel="nofollow noreferrer">JSFiddle</a>
  Below is my JSON data in JavaScript.</p>
  
  <pre><code>var JSON = [
  { name:"Maintenance",
    data:[[2017-06-26,1.5],
            [2017-07-03,5.2],
            [2017-07-10,1.65],
            [2017-07-17,2.5],
            [2017-07-24,1.5]
    ] 
  },
  { name:"Others",
    data:[[2017-06-26,1.5],
            [2017-07-03,1.5],
            [2017-07-10,1.5],
            [2017-07-17,1.25],
            [2017-07-24,1.5]
    ] 
  },
  { name:"Project",
    data:[[2017-06-26,6.5],
            [2017-07-03,6.1],
            [2017-07-10,6.7],
            [2017-07-17,7],
            [2017-07-24,6.5]
    ] 
  },
  { name:"Training",
    data:[[2017-06-26,0],
            [2017-07-03,0.75],
            [2017-07-10,1.9],
            [2017-07-17,0.5],
            [2017-07-24,1]
    ] 
  },
  { name:"Day-Off",
    data:[[2017-06-26,0],
            [2017-07-03,0],
            [2017-07-10,0],
            [2017-07-17,0],
            [2017-07-24,1]
    ] 
  }]
  </code></pre>
  
  <p>However, the chart looks strange. For every series, there is an additional line connecting the start point and the end point. In addition, the x-axis value is not the date that I want.</p>
  
  <pre><code>//Draw chart
  Highcharts.chart('trend_bl', {
  
  title: {
      text: 'Trend by Business Lines'
  },
  yAxis: {
      title: {
          text: ' Resource Allocation'
      }
  },
  legend: {
      layout: 'vertical',
      align: 'right',
      verticalAlign: 'middle'
  },
  
  series : JSON,
  });
  </code></pre>
  
  <p>Can anyone tell me why this would happen? In addition, I would also like to know the proper JSON data structure for line chart and pie chart in Highchart.</p>