title: datetime x-axis matplotlib labels causing uncontrolled overlap
body: <p>I'm trying to plot a pandas <code>series</code> with a <code>'pandas.tseries.index.DatetimeIndex'</code>.    The x-axis label stubbornly overlap, and I cannot make them presentable, even with several suggested solutions.</p>
  
  <p>I tried  <a href="https://stackoverflow.com/a/26701726/3556757">stackoverflow solution suggesting to use <code>autofmt_xdate</code></a> but it doesn't help.</p>
  
  <p>I also tried the suggestion to <code>plt.tight_layout()</code>, which fails to make an effect.</p>
  
  <pre><code>ax = test_df[(test_df.index.year ==2017) ]['error'].plot(kind="bar")
  ax.figure.autofmt_xdate()
  #plt.tight_layout()
  print(type(test_df[(test_df.index.year ==2017) ]['error'].index))
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/OKQz0.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/OKQz0.png" alt="enter image description here"></a></p>
  
  <p>UPDATE:  That I'm using a bar chart is an issue. A regular time-series plot shows nicely-managed labels.</p>
  
  <p><a href="https://i.stack.imgur.com/lxfYD.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/lxfYD.png" alt="enter image description here"></a></p>