title: Highstock - custom tickPositioner and tickInterval
body: <p>I have a Highstock chart here</p>
  
  <p><a href="http://jsfiddle.net/AVhaL/28/" rel="nofollow">http://jsfiddle.net/AVhaL/28/</a></p>
  
  <p>What I want to do is to display the "Month, Year" on the x-axis, and show only distinct "Month, Year" labels.</p>
  
  <p>The obvious way is to set the skip interval</p>
  
  <pre><code>tickInterval: 30 * 24 * 3600 * 1000,
  </code></pre>
  
  <p>But as you can see in the chart, "Mar 11" appears twice. I tried with "31", and even "32", but "Mar 11" doesn't go away.</p>