title: tickinterval not working high chart for x axis
body: <p>Here's <a href="http://jsfiddle.net/rtmv01gn/5/" rel="nofollow">a link</a> to a fiddle where i have tried plot the x axis using datetime and passed on multiple series with data points.
  Here i am unable to attain the tick marks for month of December and February</p>
  
  <p>sample x axis</p>
  
  <pre><code>    xAxis: {
  
          type: 'datetime',
          //minTickInterval: 2419200000, //time in milliseconds
          //minRange: 2419200000,
  
  
          //showLastLabel: true,
          tickInterval: 2419200000,
  
      },
  </code></pre>
  
  <p>sample data points in series</p>
  
  <pre><code>   {            
          "data": [{
  
              "x": 1420070400000,
              "y": 2,
          }, {
  
              "x": 1425168000000,
              "y": 1,                
          }],           
          "name": "Neither Dissatisfied or Satisfied",
          "color": "#5aa5dc",          
      }
  </code></pre>
  
  <p>plz help me out.</p>