title: How can I group an array of objects by month?
body: <p>I'm using JavaScript. I have an array that contains data in this format:</p>
  
  <pre><code>[
          {"USER_NAME":"User1","LAST_SUCCESSFUL_CONNECT":"1373978337642"},
          {"USER_NAME":"User2","LAST_SUCCESSFUL_CONNECT":"1374515704026"},
          {"USER_NAME":"User3","LAST_SUCCESSFUL_CONNECT":"1374749782479"}
  ]
  </code></pre>
  
  <p>(the numbers above represent UTC date/time in milliseconds.</p>
  
  <p>I would like to group (count) the data by month. Something like this:</p>
  
  <pre><code>[
      {"Month":"January, 2014","User_Count": 2},
      {"Month":"February, 2014","User_Count": 1},
  ]
  </code></pre>
  
  <p>I could use <a href="http://api.jquery.com/jQuery.map/" rel="noreferrer">jQuery</a> if it simplifies matters.</p>