Kibana discover histogram not showing documents

I am using the AWS Elasticsearch service that has Kibana 4.0.3 installed. However, when I search in the Discover tab, I get hits, but nothing shows up in the histogram graph. I have attached two screenshots with the second showing the time field that kibana is using.

Any Ideas? Thanks.

I'd say that's unexpected. Since the AWS ES+Kibana as a service is not something Elastic maintains and is running older versions of the product, I'd say it may be a problem with their service. Try Found, which is running the latest ES and Kibana versions: