title: Is there a method to get last month name and year in C#
body: <p><code>DateTime.Now.ToString("Y")</code> returns me :   August 2013</p>
  
  <p>Is there an easy method to get last month in the same format? </p>
  
  <p>Something like : <code>DateTime.LastMonth.ToString("Y")</code> and output will be : July 2013</p>
  
  <p>I know this method doesnt exists :) but maybe there is something else to achieve that output? Or I will need to create my own method for that?</p>