title: How to get Major and Minor Tick Labels
body: <p>I have the output of a group-by representing a sum of dates per week.  </p>
  
  <pre><code>Date
  2008-10-28    20.0
  2008-11-04    25.0
  2008-11-11    20.0
  2008-11-18    40.0
  2008-11-25    35.0
  2008-12-02    35.0
  2008-12-09     NaN
  2008-12-16     NaN
  2008-12-23     NaN
  2008-12-30     NaN
  Freq: W-TUE, Name: Count, dtype: float64
  </code></pre>
  
  <p>I'm trying to plot these using <code>plot_date</code></p>
  
  <pre><code>fig, ax = plt.subplots(figsize=(2, 4))
  # ax = plt.gca()
  line = ax.plot_date(a.index, a.values, '.', label='a', alpha=0.5, linewidth=1)
  ax.tick_params('y', colors='k')
  ax.set_xlabel('Date')
  ax.set_ylabel('Frequency')
  ax.set_title('Daily Games')
  ax.tick_params('y', colors='k')
  ax.grid(b=True, which='major', color='w', linewidth=1.0)
  ax.grid(b=True, which='minor', color='w', linewidth=0.5)
  ax.yaxis.grid(True)
  ax.get_xaxis().set_minor_locator(mpl.ticker.AutoMinorLocator())
  ax.set_xticklabels(ax.xaxis.get_majorticklabels(),
                      rotation=70)
  ax.set_xticklabels(ax.xaxis.get_minorticklabels(),
                      rotation=70)
  plt.xticks(rotation=70)
  plt.show()
  </code></pre>
  
  <p>This is producing a graph like so:</p>
  
  <p><a href="https://i.stack.imgur.com/9uWW0.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/9uWW0.png" alt="enter image description here"></a></p>
  
  <p>I've tried all manner of rearranging but I can't get both minor and major labels for the date to plot.</p>
  
  <p>I'd like to have each month labelled at 70 degrees. How can I adjust what I have to do so?</p>