title: Why does Vuejs not pickup changes when watching a momentjs?
body: <p>Per this question here, <a href="https://stackoverflow.com/questions/51144491/vuejs-computed-property-not-updating-the-view/51144644#51144644">Vuejs: Computed property not updating the view</a>, I am watching for changes to instances of moment.js, and the view does not update.</p>
  
  <p>Here's an excerpt from the original code that does not work:</p>
  
  <pre><code>set(value) {
      this.paidFinish = this.paidFinish.hour(value);
  }
  </code></pre>
  
  <p>Here's what I did to fix it:</p>
  
  <pre><code>set(value) {
      this.paidFinish = this.paidFinish.clone().hour(value);
  }
  </code></pre>
  
  <p>Why does Vuejs not detect the changes?  The object is being accessed via <code>this</code>, and the property <code>paidFinish</code> is present in the initial data.  (Initially it is set to <code>''</code>, but when the component is mounted it is set to a moment.)</p>