How to find out the index creation date in elasticsearch

Elasticsearch now automatically includes the creation date for an index, forexample:

If I create a new index (with no settings)

curl -XPOST 'localhost:9200/aoeu'{"acknowledged":true}

I can now 'get' the index to retrieve its metadata:

curl -XGET 'localhost:9200/aoeu'{  "aoeu": {    "aliases": {},    "mappings": {},    "settings": {      "index": {        "creation_date": "1429308615170",        "number_of_replicas": "1",        "number_of_shards": "5",        "uuid": "C5sqwXClSFyd5uF3MSrVgg",        "version": {          "created": "1050199"        }      }    },    "warmers": {}  }}

You can see the creation_date field above.

curl -XGET localhost:9200/_cat/indices?h=i,creation.date.string

Above command will output index name (i) and creation date.For more options you can try help as-

curl -XGET localhost:9200/_cat/indices?help

From the 1.4.0 version, documentation explains the following:Index creation date

When an index is created, a timestamp is stored in the index metadata for the creation date. By default this it is automatically generated but it can also be specified using the creation_date parameter on the create index API

curl -XPUT localhost:9200/test -d '{    "creation_date" : 1407751337000 }'