title: jqPlot DateAxisRenderer Strange Behaviour
body: <p>I have a fairly straightforward graph with a date axis. All the date data is in unix timestamp format. </p>
  
  <p>When I render the graph without the DateAxisRenderer the graph appears as it should do...</p>
  
  <p><a href="https://i.stack.imgur.com/y2iVH.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/y2iVH.png" alt="As expected:"></a><br>
  <sub>(source: <a href="http://193.169.90.16/withoutdaterenderer.png" rel="nofollow noreferrer">193.169.90.16</a>)</sub>  </p>
  
  <p>...but when I add in the DateAxisRenderer...</p>
  
  <p><a href="https://i.stack.imgur.com/2td6j.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/2td6j.png" alt="Not as expected"></a><br>
  <sub>(source: <a href="http://193.169.90.16/withdaterenderer.png" rel="nofollow noreferrer">193.169.90.16</a>)</sub>  </p>
  
  <p>... the data points appear jumbled.</p>
  
  <p>The only difference between these two graphs is the addition of the following lines...</p>
  
  <pre><code>renderer: $.jqplot.DateAxisRenderer,
  rendererOptions: { tickRenderer: $.jqplot.CanvasAxisTickRenderer },
  tickInterval: '7 day',
  tickOptions: { formatString: '%d %b' }
  </code></pre>
  
  <p>The whole thing is live <a href="http://193.169.90.16/index.html" rel="nofollow noreferrer">here</a>.</p>
  
  <p>Is this is a bug or am I missing something trivial?</p>