Rolling Days Function not working?

Hello, good day to you.

May we know how do we use the Rolling Days correctly?
From the screen shot attached, we have set the Rolling Days to 21 days but we are still able to select dates beyond 21 days.

Looking forward to your reply, thank you.

I checked your form and based on March 5 the calendar is showing date up to March 26 for selection - which is 21 days into the future:

This means 21 days into the future with respect to the current date.

I hope this clarifies.