def next_month(self):
        """Update calendar to show the next month."""
        if self._selection_is_visible: self._clear_selection()

        date = self.datetime(self._year, self._month, 1) + \
            self.timedelta(days=calendar.monthrange(self._year, self._month)[1] + 1)

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