title: How to convert numeric value to date format
body: <p>I imported <code>.csv</code> file containing a date in one field. But when I use <code>mode()</code> for that variable, it shows as numeric. My requirement is I need to filter the data for a given date range. Below is the input file. But I am not able to do it in any means.</p>
  
  <pre><code>2   NC  2885    23-09-2013  877.00  
  3   NC  2885    24-09-2013  876.20
  4   NC  2885    25-09-2013  876.25
  5   NC  2885    26-09-2013  876.95  
  6   NC  2885    27-09-2013  876.45
  </code></pre>