title: MVC ModelState validation failing for null value
body: <p>If I have the following model:</p>
  
  <pre><code>public class Model
  {
      public int ModelID { get; set; }
      public string Title { get; set; }
      public DateTime Created { get; set; }
  }
  </code></pre>
  
  <p>And the following controller method:</p>
  
  <pre><code>public ActionResult Create(Model model)
  {
      if (ModelState.IsValid)
      {
          model.Created = DateTime.Now;
  
          // Save to DB
      }
  }
  </code></pre>
  
  <p>In the view the Created field is hidden as I want this to populate with the timestamp of when the Create controller method is called. This fails ModelState validation due to the model.Created property being null.</p>
  
  <p>I don't want to make the model.Created property Nullable but I need to somehow specify that this field isn't required in the view. Can someone please advise how to accomplish this?</p>