public Date tomorrow()
    {
        if(checkDate(_day+1,_month,_year)==true)
        {
                Date dateN = new Date(_day+1,_month,_year);
            return dateN;
        }
        else
        if(checkDate(1,_month+1,_year)==true)
        {
                Date dateN = new Date(1,_month+1,_year);
            return dateN;
        }
        else
        if(checkDate(1,1,_year+1)==true)
        {
                Date dateN = new Date(1,1,_year+1);
            return dateN;
        }
        else
        {
                Date dateN = new Date(_day+1,_month,_year);
            return dateN;
        }
    }