We will need more information..

I just tested this now, and it works normally, no errors. Tested on 19.0, order sample converted to DB2, and I changed the order_date column to datetime (timestamp DB2 native type).

It works successfully here.

        Procedure OnClick
            Clear OrderHea
            Move 9999                to OrderHea.Order_Number
            Move 4                   to OrderHea.Customer_Number
            Move (CurrentDateTime()) to OrderHea.Order_Date
            Move "NET60"             to Orderhea.Terms
            Move "USMAIL"            to OrderHea.Ship_Via
            Move "1235 asdb"         to Orderhea.Ordered_By
            Move "CM"                to OrderHea.SalesPerson_ID
            SaveRecord OrderHea
            Showln "New Rec:" OrderHea.Order_Number  
And I can select the row successfully using db2 CLP and the proper date-time is shown.

db2 => select * from sch."OrderHea" where "Order_Number" = 9999

RECNUM      Order_Number Customer_Number Order_Date                 Terms        Ship_Via     Ordered_By   SalesPerson_ID Order_Total  Last_Detail_Num
----------- ------------ --------------- -------------------------- ------------ ------------ ------------ -------------- ------------ ---------------
       2130         9999               4 2017-09-18- NET60        USMAIL       1235 asdb    CM                     0,00               0

  1 record(s) selected.