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