jQuery UI Datepicker displayed in a jQuery Dialog

dialog-datepicker.css

#ui-datepicker-div {
  position: relative !important;
  top: 0 !important;
  left: 0 !important;
  padding: 0;
  display: block !important;
}

dialog-datepicker.js

$("#field").datepicker({
  showOn: "button",
  buttonText: "day",
  beforeShow: dialogFx,
  onSelect: dialogFxClose
});

function dialogFx() {
  $('#ui-datepicker-div').dialog({
    minHeight: 250,
    modal: true,
    open: function() {
      setTimeout(function() {
        $('#ui-datepicker-div').find('.ui-state-highlight').focus();
      }, 50);
    }
  });
}

function dialogFxClose() {
  $('#ui-datepicker-div').dialog('close');
}