kafka 0.11 reset offset for consumer group by --to-datetime

It's not an error, but just a warning - because you specified --bootstrap-server option then changes will affect only consumers that are implemented using new Java API. If you have consumers that are built using other APIs, then you need to specify --zookeeper option instead.

Invoking

bin/kafka-consumer-groups.sh --bootstrap-server localhost:9092
--group test-group --reset-offsets --all-topics --to-datetime 2017-08-04T00:00:00.000

can resets offsets to the earliest ones after the given datetime. Datetime format is yyyy-MM-ddTHH:mm:ss.xxx, 2017-08-04T00:00:00.000 for instance.

You could also reset offsets by duration. See an example below:

bin/kafka-consumer-groups.sh --bootstrap-server localhost:9092 
--group test-group --reset-offsets --all-topics --by-duration PT0H30M0S

--by-duration resets offsets to offset by duration from current timestamp. Format: 'PnDTnHnMnS'.