Thanks Vadim,
we just get at the same conclusion using the loop FOR! 
However there is the same validation problem on TMVL (hope the note will fix it).
Still we need to find a way to manage bissextile years!
I do not understand your "P.S." suggestion. We have a property called "IS_BISSEXTILE" with "Y" on every element (also days) in a year that is bissextile