A counter for displaying a formatted number based off of the current date in milliseconds and animating its change

counter

Counter = function(){
  var n = Math.round((Date.now() - 1380990000000)/1000),
      nFormatted = addCommasToNumber(n),
      delay = 10;

  $('#number').html(nFormatted);
  setInterval(function(){
      var finish = Math.round((Date.now() - 1380990000000)/1000),
          currentVal = finish-delay;

      var i = setInterval(function(){
          if (currentVal === finish) clearInterval(i);
          nFormatted = addCommasToNumber(currentVal);
          currentVal++;
          $('#number').html(nFormatted);
      }, delay*10);
  }, delay*1000);
  function addCommasToNumber(x){
      return x.toString().replace(/\B(?=(\d{3})+(?!\d))/g, ",");
  }
};