title: Get same weekend last year using moment js
body: <p>I'm trying to get the same day of the year last week so i can compare some analytics. </p>
  
  <p>Using moment i can easily do this</p>
  
  <pre><code>var today = new Date(); 
  //Sunday 4 September 2016 - Week 36
  
  var lastYear = new moment(today).subtract(12, 'months').toDate();
  //Friday 4 September 2015 - Week 37
  </code></pre>
  
  <p>What i am trying to do is get the same 'Sunday' last year, so Sunday week 36 2015</p>
  
  <p>Any idea how to do this?</p>