title: How do I extend a class with c# extension methods?
body: <p>Can extension methods be applied to the class?</p>
  
  <p>For example, extend DateTime to include a Tomorrow() method that could be invoked like:</p>
  
  <pre><code>DateTime.Tomorrow();
  </code></pre>
  
  <p>I know I can use </p>
  
  <pre><code>static DateTime Tomorrow(this Datetime value) { //... }
  </code></pre>
  
  <p>Or</p>
  
  <pre><code>public static MyClass {
    public static Tomorrow() { //... }
  }
  </code></pre>
  
  <p>for a similar result, but how can I extend DateTime so that I could invoke DateTime.Tomorrow?</p>