Formula to end time

umandiwa

Hi I have this formula that will add 1(digit) to the months following the current start month however I would like it to stop adding number after month 23. I can't figure out how to end the argument/formula so it stops adding number.

Ex: Current month is 0, Next month is 1, following month is 2 etc, last month should be 23. How do I get it to stop counting after 23

 

 

IF ITEM(Time) = 'SYS02 Filter - Input'.'Start Month (F. Export)' THEN 0 ELSE IF ITEM(Time) > 'SYS02 Filter - Input'.'Start Month (Synergi Export)' THEN PREVIOUS(Step) + 1 ELSE 0