function formatDate(language) {
  var finalDate,
    date = new Date();

  switch (language) {
    case 'en_US' :
      finalDate = date.getFullYear() + '/' + (parseInt(date.getMonth(), 10) + 1) + '/' + date.getDate();
      break;
    case 'pt_BR' :
      finalDate = date.getDate() + '/' + (parseInt(date.getMonth(), 10) + 1) + '/' + date.getFullYear();
      break;
    default :
      finalDate = date.getFullYear() + '/' + (parseInt(date.getMonth(), 10) + 1) + '/' + date.getDate();
  }

  return finalDate;
}
Write last change date (current day)
to the main _data.json file.
It will appear in the header of the Styleguide.

Additional date formats should be configured here.