For Kinesis, it seems to be, that AWS organizes its folders on S3 like: "prefix/2019/02/09/13/kinesis-stream-name-2019-02-09-10-02-32-db1db7a9-c484-40d1-b7ec-7651a55e4677"

The date in the path is UTC-time, the date in the file name is the UTC-time of the first received byte in the Kinesis stream for the specific file. This is the default behavior, so it would be nice to implement it in localstack.
client.delete_function(FunctionName=func_name)
        except Exception:
            pass
    
    additional_kwargs = kwargs
    kwargs = {
        'FunctionName': func_name,
        'Runtime': runtime,
        'Handler': handler,
        'Role': LAMBDA_TEST_ROLE,
        'Code': {
            'ZipFile': zip_file
        },
        'Timeout': LAMBDA_DEFAULT_TIMEOUT,
        'Environment': dict(Variables=envvars),
        'Tags': tags
    }
    kwargs.update(additional_kwargs)
    if layers:
        kwargs['Layers'] = layers
    client.create_function(**kwargs)
    
    if event_source_arn:
        client.create_event_source_mapping(
            FunctionName=func_name,
            EventSourceArn=event_source_arn,
            StartingPosition=starting_position
        )
def assert_objects(asserts, all_objects):