Instead of using a 3rd Party application to handle this you should include it so we can make the most of Debutify Cart.
Make it so a customer can select a specific date and time to pick-up an item in a physical location.
See "Order Delivery Date and time" application on Shopify app store for an example of what we use.
Thank you for adding a feature request,
we appreciate that you are concerned and want us to improve.
You will be happy to know that We are considering adding it to our theme soon. Have a great day.