One of my HVAC dampers is out of alignment with the little “lever” to turn it. Is there some easy/quick way that I am missing as to determining what is the open vs closed position?

Does the shaft the lever is on have a slot cut in the end?

Yep two flats on the sides of the bolt

The slats on the side of the bolt indicate the damper position. Slats parallel to duct indicate that it is full open. Slats across the duct mean it is closed.

Thank you much.