title: DateTime.Value.ToString(format) gives me 12 hour clock
body: <p>An extension of <a href="https://stackoverflow.com/questions/15809099/no-datetime-tostringstring-overload">this</a> question, I am pulling a date from a database and displaying it in a grid.</p>
  
  <p>I have the following code:</p>
  
  <pre><code>string date = "";
  DateTime? dateSent;    
  
  if (row["DateSent"] != DBNull.Value)
                      dateSent = (DateTime)row["DateSent"];
                  else dateSent = null;
  
  date = (dateSent.HasValue ? dateSent.Value.ToString("dd/MM/yyyy hh:mm:ss") : null);
  </code></pre>
  
  <p>When I add a breakpoint at the end of this block of code, I can see that the <code>DateTime?</code> variable "dateSent" has a 24-hour clock timestamp eg 14:50:34. However, when I check the value of the <code>string</code> variable "date" - it has a 12-hour clock format eg 02:50:34.</p>
  
  <p>It is not my intention to convert to a 12 hour clock format. I have two questions:</p>
  
  <ol>
  <li>Why is dateSent.Value.ToString("dd/MM/yyyy hh:mm:ss") returning a 12 hour clock timestamp?</li>
  <li>How can I avoid this and use the 24-hour clock version?</li>
  </ol>