1. reflectable
void selDate(Event evt, detail)

Source

@reflectable
void selDate(Event evt,var detail) {
  pickerOpen=false;
  //fire("change");

  Element el = evt.path.firstWhere((Element e) => e.attributes.containsKey("data-time"));
  String attr = el.attributes["data-time"];
  selectedDate = new DateTime.fromMillisecondsSinceEpoch(int.parse(attr));
}