Comparing vs the Approved Baseline vs From the previous month and remaining logic.

I am on a project where the remaining logic has the project 20 days behind, but 24 days behind the dates for the same item from the Approved baseline from 8 months prior.  Is the project 20 or 24 days behind?  I would say 20, others say 24.  24 would be more correct for a claim situation, but how often do these really end up in court or arbitration - the 20 is more practical.  In this case its not a big difference - but it can be.  In this case I am guessing calendar complications, but it can be caused by many things.