This method translates columns values into datetime objects

        :param data: original Pandas dataframe
        :param columns: list of columns to cast the date to a datetime object
        :type data: pandas.DataFrame
        :type columns: list of strings

        :returns: Pandas dataframe with updated 'columns' with datetime objects
        :rtype: pandas.DataFrame

def format_dates(self, data, columns):
        """ This method translates columns values into datetime objects

        :param data: original Pandas dataframe
        :param columns: list of columns to cast the date to a datetime object
        :type data: pandas.DataFrame
        :type columns: list of strings

        :returns: Pandas dataframe with updated 'columns' with datetime objects
        :rtype: pandas.DataFrame
        """

        for column in columns:
            if column in data.columns:
                data[column] = pandas.to_datetime(data[column])

        return data