There was a post in the old thread:
Originally Posted by timo469
I had a stay at a Resort on December 30th. The posting date is December 30th, but Amex is stating that the final entry in their system is January 1st and thus not eligible for the $250 - 2023 credit....
My request has been denied. Strongly advise against using this benefit within the last week of the period.
Interestingly, I had a checkout on 12/31/23. The resort credit just posted, and no meter movement for the 2024 credit, so I assume it used the 2023 credit. I hope you have the same automated result, despite what Amex agents may have said.