title: Histogram in matplotlib, time on x-Axis
body: <p>I am new to matplotlib (1.3.1-2) and I cannot find a decent place to start.
  I want to plot the distribution of points over time in a histogram with matplotlib.</p>
  
  <p>Basically I want to plot the cumulative sum of the occurrence of a date.</p>
  
  <pre><code>date
  2011-12-13
  2011-12-13
  2013-11-01
  2013-11-01
  2013-06-04
  2013-06-04
  2014-01-01
  ...
  </code></pre>
  
  <p>That would make</p>
  
  <pre><code>2011-12-13 -&gt; 2 times
  2013-11-01 -&gt; 3 times
  2013-06-04 -&gt; 2 times
  2014-01-01 -&gt; once
  </code></pre>
  
  <p>Since there will be many points over many years, I want to set the <code>start date</code> on my <code>x-Axis</code> and the <code>end date</code>, and then mark <code>n-time steps</code>(i.e. 1 year steps) and finally decide how many <code>bins</code> there will be. </p>
  
  <p>How would I achieve that? </p>