Sets the duration for this item to the inputed duration.
        
        :param      duration | <int>

def setDuration(self, duration):
        """
        Sets the duration for this item to the inputed duration.
        
        :param      duration | <int>
        """
        if duration < 1:
            return False
        
        self.setDateEnd(self.dateStart().addDays(duration - 1))
        return True