title: Axis interval spacing when plotting with pandas timedelta
body: <p>I'm trying to plot some columns in a dataframe that has pandas timedelta values as its index. When I plot it, all the points are evenly spaced along the x axis even if there's a variable time between.</p>
  
  <pre><code>time = [pd.Timestamp('9/3/2016')-pd.Timestamp('9/1/2016'),pd.Timestamp('9/8/2016')-pd.Timestamp('9/1/2016'),pd.Timestam\p('9/29/2016')-pd.Timestamp('9/1/2016')]
  df = pd.DataFrame(index=time, columns=['y'],data=[5,0,10])
  df.plot()
  plt.show()
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/cZmie.png" rel="nofollow noreferrer">Wrong spacing</a></p>
  
  <p>If instead I used dates instead of timedelta, I get the proper spacing on the x axis:</p>
  
  <pre><code>time = [pd.Timestamp('9/3/2016'),pd.Timestamp('9/5/2016'),pd.Timestamp('9/20/2016')]
  df = pd.DataFrame(index=time, columns=['y'],data=[5,0,10])
  df.plot()
  plt.show()
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/ngK2R.png" rel="nofollow noreferrer">Right spacing</a></p>
  
  <p>Is there a way to get this to display correctly?</p>