StickElement.js

<script type="text/javascript">
$(document).ready(function () { 
  //checks if the number of posts on this page are more than one then return.
  if($('.post-outer').length > 1)
  return;
  //selects the element to be made sticky.
  var stickElement = $('.date-header'),
    //selects the element which would trigger the sticky elem to go away
    hideTrigger = $('#comments'),
    //class name to be added (it should match the class in CSS)
    fixed = "fixed",
    top = stickElement.offset().top;
  $(window).scroll(function (event) {
    var y = $(this).scrollTop();
  var maxY = hideTrigger.offset().top;
    if (y >= top && y < maxY) {
      stickElement.addClass(fixed);
    } else {
      stickElement.removeClass(fixed);
    }
  });
});
</script>