I have a chats collection which given down below { “_id” : ObjectId(“5a44e6545818041cde24aac9”), “messages” : [ { “createdAt” : ISODate(“2017-12-23T07:46:29.201Z”), “message” : “Hii”, “userId” : “000000” }, { “createdAt” : ISODate(“2017-12-23T12:46:29.201Z”), “message” : “Bye gtg ttyl”, “userId” : “111111” }, { “createdAt” : ISODate(“2017-12-24T07:46:29.201Z”), “message” : “Bye Take Care”, “userId” : “000000” } ], “createdAt”Read more