title: get data from mongodb document by month
body: <p>I have a user document and have createdAt, so what should I do in the condition in order to get the data by month?</p>
  
  <p>the createdAt value look like this </p>
  
  <pre><code>2016-10-08T16:21:40.935Z
  Account.find({'what to pass here?'}, function(err,response){
          if(!err){
              console.log(response)
          }
      });
  </code></pre>