title: Formatting date using Angular
body: <p>Why the following code produces strange output (looks like moment().valueOf() returns 0)</p>
  
  <pre><code>Since 7 days ago : {{(moment().valueOf()  - 7*24*60*60*1000)  | date:'yyyy-MM-dd' }}
  </code></pre>
  
  <p>returns</p>
  
  <pre><code>Since 7 days ago : 1969-12-25
  </code></pre>