code: public final ReadOnlyObjectProperty<LocalDate> startDateProperty() {
          if (startDate == null) {
              startDate = new ReadOnlyObjectWrapper<>(this, "startDate", _startDate); //$NON-NLS-1$
          }
          return startDate.getReadOnlyProperty();
      }
docs: The date where the view starts to appear (not the start date of the
  calendar entry). In most views the start and end date of an entry view
  are the same date (the date shown by the control). However, the
  {@link AllDayView} lays out entry views across multiple days.
  
  @return the start date of the view