Google Customer Review script code (Estimated Delivery Date)

I'm implementing the Google Customer Review script on my ecommerce's "Thank You" page. The only problem is that I can't pull a date 1 month from current month to show up on "estimated_delivery_date". Everything else is working fine.

The date has to be exactly in this format: "yyyy-mm-dd".

Here's the code I have so far:

<script>
var emailAddress = Order[9]; // pulls customer's email
var datePurchased = new Date();
var yyyy = datePurchased.getFullYear();
var mm = datePurchased.getMonth()+1;
var dd = datePurchased.getDate();
var delivery = yyyy+'-'+mm+'-'+dd;

  window.renderOptIn = function() {
    window.gapi.load('surveyoptin', function() {

      window.gapi.surveyoptin.render(
        {
          "merchant_id": 7654321,
          "order_id": "$(OrderNo)", // pulls order number
          "email": emailAddress, // pulls customer's email
          "delivery_country": "US",
          "estimated_delivery_date": "delivery", // not pulling delivery date. Why?
        });
    });
  }
</script>

Thanks for the help!

You are passing delivery as string:

"estimated_delivery_date": "delivery", // not pulling delivery date. Why?

Try:

<script>
var emailAddress = Order[9];
var datePurchased = new Date();
var yyyy = datePurchased.getFullYear();
var mm = datePurchased.getMonth()+1;
var dd = datePurchased.getDate();
var delivery = yyyy+'-'+mm+'-'+dd;

  window.renderOptIn = function() {
    window.gapi.load('surveyoptin', function() {

      window.gapi.surveyoptin.render(
        {
          "merchant_id": 7654321,
          "order_id": "$(OrderNo)",
          "email": emailAddress,
          "delivery_country": "US",
          "estimated_delivery_date": delivery
        });
    });
  }
</script>