Used for moving to next business day.

def next_bday(self):
        """
        Used for moving to next business day.
        """
        if self.n >= 0:
            nb_offset = 1
        else:
            nb_offset = -1
        if self._prefix.startswith('C'):
            # CustomBusinessHour
            return CustomBusinessDay(n=nb_offset,
                                     weekmask=self.weekmask,
                                     holidays=self.holidays,
                                     calendar=self.calendar)
        else:
            return BusinessDay(n=nb_offset)