DRY Out Your Code with Functions

original.js

// repetitive code!
function updateDates() {
  var startDate = $("#start-date").datepicker("getDate");

  $("#menu-item-1 .day").text(startDate.getDate());
  $("#menu-item-1 .month").text(Util.monthToText(startDate.getMonth()));
  $("#menu-item-1 .year").text(startDate.getFullYear());

  var endDate = $("#end-date").datepicker("getDate");

  $("#menu-item-2 .day").text(endDate.getDate());
  $("#menu-item-2 .month").text(Util.monthToText(endDate.getMonth()));
  $("#menu-item-2 .year").text(endDate.getFullYear());
}

refactored.js

function updateDates() {
  updateRegions('#start-date', '#menu-item-1');
  updateRegions('#end-date', '#menu-item-2');

  function updateRegions(datepickerElement, targetElement) {
    var date = $(datepickerElement).datepicker('getDate');
    var target = $(targetElement);

    target.find(".day").text(date.getDate());
    target.find(".month").text(Util.monthToText(date.getMonth()));
    target.find(".year").text(date.getFullYear());
  }
}

Just a little thing...

In the refactored code above, the updateRegions function will be created every time updateDates is called, won't it?