How to fix datepicker work?

Question

JavaScript

http://test.jethunter.net - if you start filling out the form, a datepicker will appear, in which if you click on the arrows (previous month / next month), the datepicker disappears.
Looked here:
stackoverflow.com/questions/22768094/bootstrap-3-p... and here
stackoverflow.com/questions/18607414/jquery-datepi...
but can't figure out what's wrong .
How to fix?

Answer 1

After losing focus by input, this timeout code hides your datepicker:

$('#dateDepartureInput, #dateArrivalInput').on('focus', function () {
  $(this).siblings('.js-datepicker-wrap').removeClass('hidden');
}).on('focusout', function () {
  var $this = $(this);
  setTimeout(function () {
    $this.siblings('.js-datepicker-wrap').addClass('hidden');
  }, 500);
});

PS the hidden class is very bad practice, ui.datepicker has its own ".datepicker('hide')" method.
All this should be replaced by:

$('#dateDepartureInput, #dateArrivalInput').datepicker({
  showOn: "focus"
});