title: Pandas date_range from DatetimeIndex to Date format
body: <p>Pandas <code>date_range</code> returns a <code>pandas.DatetimeIndex</code> which has the indexes formatted as a timestamps (date plus time). For example:</p>
  
  <pre><code>In  [114] rng=pandas.date_range('1/1/2013','1/31/2013',freq='D')
  In  [115] rng
  Out [116]
  &lt;class 'pandas.tseries.index.DatetimeIndex'&gt;
  [2013-01-01 00:00:00, ..., 2013-01-31 00:00:00]
  Length: 31, Freq: D, Timezone: None
  </code></pre>
  
  <p>Given I am not using timestamps in my application, I would like to convert this index to a date such that:</p>
  
  <pre><code>In  [117] rng[0]
  Out [118]
  &lt;Timestamp: 2013-01-02 00:00:00&gt;
  </code></pre>
  
  <p>Will be in the form <code>2013-01-02</code>.</p>
  
  <p>I am using pandas version 0.9.1</p>