AT&T iPhone 5 over night shipping?

I'm attempting to order my iPhone 5 from the At&t website and I notice how there's an overnight shipping option, I was wondering how exactly would that work since for priority mail there's pretty much a 3 week ship time.

Watch out, you can be charged for an extra service that can't be applied.
Below is the official answer from ATT:
"I apologize for the confusion regarding the overnight shipping option. We appreciate your feedback about it we'll make sure to have it corrected. The expectation set for customer who just recently ordered the iphone 5 from the 21st up until now will still follow the 21 to 28 business days shipping."

I want a iphone 7