code: def get_epoch_namespace_receive_fees_period( block_height, namespace_id ):
      
      epoch_config = get_epoch_config( block_height )
      if epoch_config['namespaces'].has_key(namespace_id):
          return epoch_config['namespaces'][namespace_id]['NAMESPACE_RECEIVE_FEES_PERIOD']
      else:
          return epoch_config['namespaces']['*']['NAMESPACE_RECEIVE_FEES_PERIOD']
docs: how long can a namespace receive register/renewal fees?