title: Why DateTime.TryParse returning false when given a real year string?
body: <p>In the code below I am giving the function a sTransactionDate="1999" and I am trying to covert it to a date x/x/1999. </p>
  
  <pre><code>DateTime dTransactionDate = new DateTime();
  if(DateTime.TryParse(sTransactionDate, out dTransactionDate))
  { //Happy 
  }else
  { //Sad 
  }
  </code></pre>
  
  <p>if the string is "1999" it will always end up in sad.  Any ideas?</p>