code: private void zInternalSetLastValidTimeAndNotifyListeners(LocalTime newTime) {
          LocalTime oldTime = lastValidTime;
          lastValidTime = newTime;
          if (!PickerUtilities.isSameLocalTime(oldTime, newTime)) {
              for (TimeChangeListener timeChangeListener : timeChangeListeners) {
                  TimeChangeEvent timeChangeEvent = new TimeChangeEvent(this, oldTime, newTime);
                  timeChangeListener.timeChanged(timeChangeEvent);
              }
              // Fire a change event for beans binding.
              firePropertyChange("time", oldTime, newTime);
          }
      }
docs: zInternalSetLastValidTimeAndNotifyListeners, This should be called whenever we need to change
  the last valid time variable. This will store the supplied last valid time. If needed, this
  will notify all time change listeners that the time has been changed. This does not perform
  any other tasks besides those described here.