We use Paypal for all the payment options (customer is forwarded to the Paypal site to do a PayPal payment but stays within the shopping cart if paying by credit card /still settled by PayPal though/). I installed the Amasty's Delivery Date extension (basically a calendar) which appears on the Shipping step of the order /3 SHIPPING METHOD/ ( https://amasty.com/delivery-date.html )
I selected that customer MUST fill out the delivery date (it is mandatory). It works fine except for cases where customers pay with Paypal - then - it does not pass the delivery date back to the order in the Admin or the order Email.
**It works if the customer pays with a credit card (still processed by Paypal BUT I just noticed that when I click on option #1 (Debit or Credit Card) - it stays inside my shopping cart (the customer IS NOT forwarded to the Paypal site) - it just opens 4 rows:
> > 1. Credit Card Type
> > 2. Credit Card Number
> > 3. Expiration Date
> > 4. Card Verification Number
So it must just be when the customer goes to the Paypal site!