I'm using the calworkdays to get the number of days for a turnaround time report.

@mjmallet A simple way of cracking this could be identifying the pattern. That is, all the rows that has got null values in them might have chosen a different if() condition (out of the several if() conditions that were part of your script) or atleast a variable or a data type of it, a value for it might be causing an issue. This could be quickly identified if you differentiate the PVs, their data types and their values for an instance that has got proper value and a instance that has got a null value. Perhaps this might give you leads quickly.

@mjmallet A simple way of cracking this could be identifying the pattern. That is, all the rows that has got null values in them might have chosen a different if() condition (out of the several if() conditions that were part of your script) or atleast a variable or a data type of it, a value for it might be causing an issue. This could be quickly identified if you differentiate the PVs, their data types and their values for an instance that has got proper value and a instance that has got a null value. Perhaps this might give you leads quickly.