def tzname(self, dt):
        """
        http://docs.python.org/library/datetime.html#datetime.tzinfo.tzname

        """
        sign = '+'
        if self.__offset < datetime.timedelta():
            sign = '-'

        # total_seconds was introduced in Python 2.7
        if hasattr(self.__offset, 'total_seconds'):
            total_seconds = self.__offset.total_seconds()
        else:
            total_seconds = (self.__offset.days * 24 * 60 * 60) + \
                            (self.__offset.seconds) + \
                            (self.__offset.microseconds / 1000000.0)

        hours = total_seconds // (60 * 60)
        total_seconds -= hours * 60 * 60

        minutes = total_seconds // 60
        total_seconds -= minutes * 60

        seconds = total_seconds // 1
        total_seconds -= seconds

        if seconds:
            return '%s%02d:%02d:%02d' % (sign, hours, minutes, seconds)
        else:
            return '%s%02d:%02d' % (sign, hours, minutes)
http://docs.python.org/library/datetime.html#datetime.tzinfo.tzname