Hi,
The point is if you have to do calculations on date and its char then you convert the date char into keyfigure by using formula variable with replacement path and in that its mandatory to keep 0date in rows for formula variable to work properly.
So to avoid all that i suggested to make 0date as keyfigure at modeling level.This way you can easily do calculations on date.
Hope that helps.
In case you don't get that then share your requirement in new thread.
Regards,
AL