Laravel Model created_at inconsistent display - php

Question

I am new to laravel and php,
I have the code below, REST API
public function sendMessage(Request $request)
{
$message = Message::create($request->all());
return response()->json(['result'=>'success','created_at'=>$message->created_at],200);
}
This is displayed like this in the postman
{
"result": "success",
"created_at": "2020-06-29T23:31:32.000000Z"
}
If I change the return message-object by changing return statement to
return response()->json(['result'=>'success','created_at'=>$message],200);
Then time format is displayed differently as below
{
"result": "success",
"created_at": {
"sender": "47",
"receiver": "23",
"message": "hello world reply",
"updated_at": "2020-06-29 23:38:53",
"created_at": "2020-06-29 23:38:53",
"id": 515
}
}
I do not want this form "2020-06-29T23:31:32.000000Z" when I access it as a property,not sure what is this 00000Z at then end. want it like this "2020-06-29 23:38:53" Any help

Answer 1

When you access the data member ->created_at you get a Carbon instance, instead if you serialize the object, you get its attribute.
This is why you are getting two different serialization, because you are serializing two different things (one is a Carbon instance, the onthe one is a Model)

Answer 2

If you convert the Carbon instance to a string it will be in the same format as you see in the serialized model. When you pass it without doing this it is going to json_encode the value which will return it how you are currently seeing it.
return response()->json([
'result' => 'success',
'created_at' => (string) $message->created_at
],200);