title: Mocking DateTime
body: <pre><code>public void DoSomethingAccordingToYear()
  {
      if(DateTime.Now.Year &lt; 2010)
          DoSomething();
      else
          DoSomethingElse();
  }
  </code></pre>
  
  <p>I want to test this method.
  How can I mock DateTime <strong>without changing my code and without using interfaces</strong>?</p>