Datepicker languageCode is not working

[Rostyk Chuma]

Hi Community 

I have faced with languageCode problem in confluance server.

Seems like Date picker languageCode does not work.

I have tried examples from AUI docu but it did not work too.

<input class="aui-date-picker" id="demo-range-1" type="date" />

AJS.$("#demo-range-1").datePicker({
  'overrideBrowserDefault' : true,
  'languageCode' : 'de'
});

After investigation and debugging source code I have found that languageCode = "". Looks like there is no translations, so I have a question - how can I add those missed files to my resources?