https://groups.google.com/forum/#!topic/elasticsearch/0AWUInB9-uY

timestamp_sort.sh

curl -XDELETE localhost:9200/test
curl -XPUT localhost:9200/test -d '{
    "settings": {
        "index.number_of_shards": 1,
        "index.number_of_replicas": 0
    },
    "mappings": {
        "doc": {
            "_timestamp" : { "enabled" : true }
        }
    }
}'
curl -XPUT localhost:9200/test/doc/1 -d '{"foo": "1"}'
sleep 1
curl -XPUT localhost:9200/test/doc/2 -d '{"foo": "2"}'
sleep 1
curl -XPUT localhost:9200/test/doc/3 -d '{"foo": "3"}'
sleep 1
curl -XPOST localhost:9200/test/_refresh
echo
curl "localhost:9200/test/doc/_search?sort=_timestamp&pretty=true&fields=foo"
echo