Could you explain why exactly you want/need an LOD? Is there a specific reason?
The straight forward way to count the day difference is using the date diff function:
DATEDIFF('day', (min([Final Check-Out])), (max([Final Check-Out])))
No LOD is required for this.
Date Range_v10.2.twbx 7.4 MB
Eventually, it was an in the middle thing.
Exclude was needed in your calculations , as in different cases of aggregation the min /max was changing, but with the fixed it didn't work.