iReport and Jaspersoft Studio: Useful Expressions

Hello,

Thanks for these handy expressions.

I have the following issue though… When I use the expressions that replaces month with Roman numeral I get always values for month and day despite that for some entries I have entered only year. Should not for these cases $F{1,10.collectingevent.startDateNumericDay}==null? (and consequently, $F{1,10.collectingevent.startDateNumericMonth}==null?) be TRUE?
How to stop values entered only as Year, e.g. 2023, appear as 1-I-2023?