$(function() {
  $("#depDate").datepicker({
    dateFormat: "dd/mm/yy",
    minDate: "+7 days",
    onSelect: updateArrDate
  });
  $("#arrDate").datepicker({
    beforeShow: setArrDateMin,
    dateFormat: "dd/mm/yy",
    minDate: "+9 days"
  });
});

function updateArrDate(date) {
  $("#arrDate").val(date);
}

function setArrDateMin(input) {
  return {
    minDate: $("#depDate").datepicker('getDate')
  };
}