The FAQs don't explicitly explain this:

If we book awards by Dec. 15, it says we can cancel them and they are not refundable. They don't explain if we can change the dates once booked. For example, if I book an Anytime award to Europe for December 2024, can I call any time in 2024 to change it to another date? or will the Biz Extra team be gone and the normal reservations team won't have access to Anytime inventory to change dates? Im trying to book a hold date later in 2024 and then change it when I know my actual dates of travel, but need to know if I will be able to do so. Biz Extra has a two hour hold time, of course.