def initialize_period(self, period=None):
        """Initialize the period of BF.

        :period: datetime.datetime for setting the period explicity.
        """
        if not period:
            self.current_period = dt.datetime.now()
        else:
            self.current_period = period
        self.current_period = dt.datetime(self.current_period.year, self.current_period.month, self.current_period.day)
        self.date = self.current_period.strftime("%Y-%m-%d")
Initialize the period of BF.

        :period: datetime.datetime for setting the period explicity.