Failed to create mapping["date"], following steps in getting started doc

[ I posted this question (and others) on Google Groups with no response so I'm trying this newbie question here. ]

I've played a bit with Elasticsearch and now I'm wanting to get going with logstash. I found this document:

http://www.elastic.co/guide/en/logstash/current/getting-started-with-logstash.html

The steps work fine until I want to add a record to my existing Elasticsearch and then I get this:

[2015-05-13 12:09:13,999][DEBUG][action.admin.indices.create] [Captain Germany] [logstash-2015.05.13] failed to create org.elasticsearch.index.mapper.MapperParsingException: mapping [“date”]at org.elasticsearch.cluster.metadata.MetaDataCreateIndexService$2.execute(MetaDataCreateIndexService.java:395)at org.elasticsearch.cluster.service.InternalClusterService$UpdateTask.run(InternalClusterService.java:365)

...

I assume the problem is caused by the fact that logstash is trying to write into some database that either doesn't have a date field or else its mapping is wrong.

In any case, how do I get this to not throw an error?

bin/logstash -e 'input { stdin { } } output { elasticsearch { host => localhost }

Thanks.