Auto-Renewing subscription purchase_date and expires_date are equal

I'm trying to implement In-AppPurchaceses(Auto-Renewing) for the first time.

I'm trying to verify receipt with itunes.apple.com/verifyReceipt. But in the response 'purchase_date_ms' and 'expires_date_ms' are equal,

I mean 'purchase_date_ms' is correct but 'expires_date_ms' should be aligned to the subscription period isn't it?

But it isn't in mine, Does this happen because I'm in the sandBox environment?

SUBSCRIPTION IS ONE MONTH AUTO RENEWING.

Validating the recipe code

        guard let receiptURL = Bundle.main.appStoreReceiptURL else {return}
        guard let receipt = NSData(contentsOf: receiptURL) else {return}

        let requestContents: [String: Any] = [
            "receipt-data": receipt.base64EncodedString(options: []),
            "password": "8ae••••••••••••••••••••"
        ]

        let appleServer = receiptURL.lastPathComponent == "sandboxReceipt" ? "sandbox" : "buy"

        let stringURL = "https://\(appleServer).itunes.apple.com/verifyReceipt"

        var request = URLRequest(url: URL(string: stringURL)!)
        request.httpMethod = "POST"
        request.setValue("application/json", forHTTPHeaderField: "Content-Type")
        request.httpBody = try? JSONSerialization.data(withJSONObject: requestContents)

        let task = URLSession.shared.dataTask(with: request) { (data, response, error) in
            if error != nil{
                print("====================")
                print(error.debugDescription)
                return
            }
            guard let data = data else {return}
            guard let response = response else {return}
            guard let httpStatus = response as? HTTPURLResponse else {return}

            if(httpStatus.statusCode == 200){
                do {
                    let json = try JSONSerialization.jsonObject(with: data, options: .mutableContainers)

                    print(json)

                }catch let error{
                    print(error)
                }
            }
        }

        task.resume()

A part of the response

{
  "status": 0,
  "environment": "Sandbox",
  "receipt": {
    "receipt_type": "ProductionSandbox",
    "app_item_id": 0,
    "receipt_creation_date": "2019-06-03 05:24:56 Etc/GMT",
    "bundle_id": "•••••",
    "original_purchase_date": "2013-08-01 07:00:00 Etc/GMT",
    "in_app": [
      {
        "quantity": "1",
        "purchase_date_ms": "1559277785000",
        "expires_date": "2019-05-31 04:48:05 Etc/GMT",
        "expires_date_pst": "2019-05-30 21:48:05 America/Los_Angeles",
        "is_in_intro_offer_period": "false",
        "transaction_id": "1000000533091664",
        "is_trial_period": "false",
        "original_transaction_id": "1000000532336547",
        "purchase_date": "2019-05-31 04:43:05 Etc/GMT",
        "product_id": "••••••••",
        "original_purchase_date_pst": "2019-05-29 01:41:31 America/Los_Angeles",
        "original_purchase_date_ms": "1559119291000",
        "web_order_line_item_id": "1000000044695000",
        "expires_date_ms": "1559278085000",
        "purchase_date_pst": "2019-05-30 21:43:05 America/Los_Angeles",
        "original_purchase_date": "2019-05-29 08:41:31 Etc/GMT"
      }
    ],
    "adam_id": 0,
    "receipt_creation_date_pst": "2019-06-02 22:24:56 America/Los_Angeles",
    "request_date": "2019-06-03 05:25:10 Etc/GMT",
    "request_date_pst": "2019-06-02 22:25:10 America/Los_Angeles",
    "version_external_identifier": 0,
    "request_date_ms": "1559539510983",
    "original_purchase_date_pst": "2013-08-01 00:00:00 America/Los_Angeles",
    "application_version": "88",
    "original_purchase_date_ms": "1375340400000",
    "receipt_creation_date_ms": "1559539496000",
    "original_application_version": "1.0",
    "download_id": 0
  },
  "pending_renewal_info": [
    {
      "product_id": "Monthly.Global.JGSW.Lawganizer",
      "original_transaction_id": "1000000532336547",
      "is_in_billing_retry_period": "1",
      "auto_renew_product_id": "••••••••",
      "auto_renew_status": "1"
    },
    {
      "expiration_intent": "4",
      "original_transaction_id": "1000000531941094",
      "is_in_billing_retry_period": "1",
      "auto_renew_product_id": "••••••",
      "product_id": "global.JGSW.Lawganizer.3Months",
      "auto_renew_status": "1"
    }
  ],
  "latest_receipt_info": [

    {
      "quantity": "1",
      "purchase_date_ms": "1559277785000",
      "expires_date": "2019-05-31 04:48:05 Etc/GMT",
      "expires_date_pst": "2019-05-30 21:48:05 America/Los_Angeles",
      "is_in_intro_offer_period": "false",
      "transaction_id": "1000000533091664",
      "is_trial_period": "false",
      "original_transaction_id": "1000000532336547",
      "purchase_date": "2019-05-31 04:43:05 Etc/GMT",
      "product_id": "••••••••••",
      "original_purchase_date_pst": "2019-05-29 01:41:31 America/Los_Angeles",
      "original_purchase_date_ms": "1559119291000",
      "web_order_line_item_id": "1000000044695000",
      "expires_date_ms": "1559278085000",
      "purchase_date_pst": "2019-05-30 21:43:05 America/Los_Angeles",
      "original_purchase_date": "2019-05-29 08:41:31 Etc/GMT"
    }
  ],
  "latest_receipt": "rtyu...56"
}

In sandbox mode, Monthly auto-renewing subscription renew in 5 mins interval and in half an hour it automatically gets cancelled. In case of yearly subscription, it auto renew in half n hour time.