def select_next_day(self):
        """Update calendar to show the next day."""

        if self._selected_date is None:
            self._selected_date = datetime.datetime(self._year, self._month, 1)
        else:
            self._clear_selection()
            self._selected_date = self._selected_date + self.timedelta(days=1)

        self._build_calendar(self._selected_date.year, self._selected_date.month) # reconstruct calendar
Update calendar to show the next day.
recipes/Python/580725_Tkinter_Datepicker_like_jQuery_UI/recipe-580725.py