「14-12-2012」のような文字列形式の日付があります。日付を文字列から日付に変換すると、「#12/14/2012#」のようになります。
次に、データベースに日付を保存しようとしていますが、エラーが発生しています。
Dim queryString As String = "UPDATE [ARIBA_CUST_ADMIN] SET [CUST_CRED_ID] = '" + eCustomer.CUST_CRED_ID + "',[CUST_NAME] = '" + eCustomer.CUST_NAME + "',[STREET1] = '" + eCustomer.STREET1 + "',[STREET2] = '" + eCustomer.STREET2 + "',[CITY] = '" + eCustomer.CITY + "',[State] = '" + eCustomer.STATE + "',[POSTAL_CD] = '" + eCustomer.POSTAL_CD + "',[COUNTRY] = '" + eCustomer.COUNTRY + "',[CUST_CRED_DOMAIN] = '" + eCustomer.CUST_CRED_DOMAIN + "',[SUBCHARGE] = '" + eCustomer.SUBCHARGE + "',[TAX_AT_LINE] = '" + eCustomer.TAX_AT_LINE + "',[PO_FLIP] = '" + eCustomer.PO_FLIP + "',[STATUS] = '" + eCustomer.STATUS + "',[CONFIMRATIONS] = '" + eCustomer.CONFIMRATIONS + "',[SHOP_NOTICES] = '" + eCustomer.SHOP_NOTICES + "',[INVOICE_TYPE] = '" + eCustomer.INVOICE_TYPE + "',[EFFECTIVE_DATE] = " + eCustomer.EFFECTIVE_DATE + ",[DISTRIBUTION_XML] = '" + eCustomer.DISTRIBUTION_XML + "' WHERE [CUST_ID] = " + eCustomer.CUST_ID