问第二个日期参数抛出ORA-01843:无效的月份错误

EN

        StringBuilder sql = new StringBuilder();
        DateTime yearBegin = new DateTime(Convert.ToInt32(taxYear) + 1, 1, 1);
        DateTime yearEnd = new DateTime(Convert.ToInt32(taxYear) + 1, 12, 31);
        sql.Append(
            "SELECT * FROM TABLE WHERE FIELD = '1099' AND CREATED_DT >= TO_DATE(:createdYearBegin, 'MM/DD/YYYY') AND CREATED_DT <= TO_DATE(:createdYearEnd, 'MM/DD/YYYY') AND SSN = :ssn");
        try
        {
            using (OracleConnection cn = new OracleConnection(ConfigurationManager.AppSettings["cubsConnection"]))
            using (OracleCommand cmd = new OracleCommand(sql.ToString(), cn))
            {
                cmd.Parameters.Add("ssn", ssn);
                cmd.Parameters.Add("createdYearBegin", yearBegin.ToShortDateString());
                cmd.Parameters.Add("createdYearEnd", yearEnd.ToShortDateString());
                cn.Open();
                OracleDataReader dr = cmd.ExecuteReader(CommandBehavior.CloseConnection);
                ret = dr.HasRows;
            }
        }