Printing a future date on a POS Receipt

I am trying to add a future date on our Shopify POS (Pro) receipts so that customers have a printed date on the receipt that tells them the date that a return or exchange needs to by completed by. Even though we state that the return window is 30 days from the date of original purchase I want the future date printed on the receipt.

Have tried a couple of variations for adding the code and when it is shown on the administration backend:

Sales Channels > Point of Sale > Settings > Customize / Receipts > Customize your receipts

The preview correctly shows the future date. BUT, when printing at POS, it prints as ‘Invalid Date’

This code is currently in place:

{% assign return_date = order.created_at | date: '%s' | plus: '2592000' %}
 {{ return_date | date: "%B %d, %Y" }}

Any guidance on how to get the calculated future date to print on the receipt properly?

Thank you-

Thad