fullcalendar annotations

fullcalendar.annotations.css

/* Global Annotation Styles
------------------------------------------------------------------------*/

.fc-annotation {
  border-style: solid;
  border-width: 0;
  font-size: .85em;
  cursor: default;
  }

.fc-annotation-skin {
  border-color: #999;     /* default BORDER color */
  background-color: #edb; /* default BACKGROUND color */
  color: #777;            /* default TEXT color */
  text-align: center;
  opacity: 0.8;
  filter: alpha(opacity=80); /* for IE */
  }

.fc-annotation.closed {
  background-color: #f1f1f1;
}

fullcalendar.annotations.js

function renderAnnotations(view,annotations) {
  var container = $(view.element).find('.fc-agenda-slots').parent();
  if ( container.find('#annotationSegmentContainer').length === 0 ) {
    annotationSegmentContainer = $("<div style='position:absolute;z-index:-1;top:0;left:0' id='annotationSegmentContainer'>").prependTo( container );
  }
  else {
    annotationSegmentContainer = container.find('#annotationSegmentContainer');
  }

  var html = '';
  for (var i=0; i < annotations.length; i++) {
    var ann = annotations[i];
    if (ann.start >= view.start && ann.end <= view.end) {
      var top = view.timePosition(ann.start, ann.start);
      var bottom = view.timePosition(ann.end, ann.end);
      var height = bottom - top;
      var dayIndex = $.fullCalendar.dayDiff(ann.start, view.visStart);

      var left = view.colContentLeft(dayIndex) - 2;
      var right = view.colContentRight(dayIndex) + 3;
      var width = right - left;

      var cls = '';
      if (ann.cls) {
        cls = ' ' + ann.cls;
      }

      var colors = '';
      if (ann.color) {
        colors = 'color:' + ann.color + ';';
      }
      if (ann.background) {
        colors += 'background:' + ann.background + ';';
      }

      var body = ann.title || '';

      html += '<div style="position: absolute; ' +
        'top: ' + top + 'px; ' +
        'left: ' + left + 'px; ' +
        'width: ' + width + 'px; ' +
        'height: ' + height + 'px;' + colors + '" ' +
        'class="fc-annotation fc-annotation-skin' + cls + '">' +
        body +
        '</div>';
    }
  }
  annotationSegmentContainer.html(html);
}

fullcalendar.js

// Add to line 1255
// or add to top of date_util.js if you are building manually

fc.dayDiff = dayDiff;

In fullcalendar.js file of main file i dont find the place where i can add the above lines.please let me know where to add fc.dayDiff in latest version of fullcalendar.js file