title: Get previous business day with moment.js
body: <p>What's the best way to get the previous business day's date with <a href="http://momentjs.com/docs/" rel="nofollow">moment.js</a>? A business day is Monday through Friday.</p>
  
  <p>Some expectations:</p>
  
  <ul>
  <li>If today is Satuday, Sunday or Monday, return last Friday's date</li>
  <li>If today is Tuesday, return last Monday's date (yesterday)</li>
  </ul>