Can I change delivery date info in Magento admin panel?

Yes, to do that you should open the order you want to modify, Delivery Date -> Edit. There is also an option to notify a customer about delivery date change:

Magento Delivery Date extension by Amasty

See more details on Delivery Date page

How can we help you?

Didn’t you find the answer to your question? We are always happy to help you out.