How to parse DateTime from Logstash to Elasticsearch?

Elastic Stack Elasticsearch
1

Hi,

I have a json object which contains timestamp assume under field x. Here is an example of a json object
[ { "name":"milin","log_time":"9/6/2016 3:30:22 PM" }, { "name":"joshi","log_time":"9/6/2016 3:30:23 PM" } ]

How do I extract just the date part from the above json using logstash/Elasticsearch and insert it in Elasticsearch?