1. Create a content (optional).
  2. Add a date, datetime or datestamp field to the content type.
  3. Go on the "Admin" => "Content types" => "<Your content type>" => "Display fields" tab.
  4. Set the formatter of your date field to "date_picker_formatter" (leave the other settings blank, they have no impact on the date_picker_formatter formatter).
  5. Check the permissions of the field.