title: Python: My x axis labels do not show, only the column header
body: <p>The x-axis should be a series of dates; instead, I'm getting just the my_date header. How do I return the dates? By the way, I am visualizing the number of daily registrations for a project.</p>
  <pre><code>viz = registrations.groupby('my_date').count()[['event_type']]
  viz.plot()
  </code></pre>