title: NSDateFormatter, dateFromString returns nil
body: <p>Added this code</p>
  
  <pre><code>NSDateFormatter *df = [[NSDateFormatter alloc]init];
  NSString *entry = @"March 28, 2012";       
  [df setDateFormat:@"yyyy-MM-dd"];     
  NSDate *date = [df dateFromString:entry]; 
  </code></pre>
  
  <p>The date returns nil value. I have doubt about the entry date string.Is it possible to convert this into date?</p>