setting max date value to oracle 10g from sql2000+n

Question

Hi I have this update statement

UPDATE OPENQUERY(linkedServerToOracle ,"SELECT   T$TDAT FROM BAAN.TTDSLS031010 WHERE T$CUNO='003098' AND T$CPGS=' 4AN00'") 
SET T$TDAT=CONVERT(varchar, '4712-01-01 00:00', 121)

and the current setting in linkedServerToOracle (10g) is supposed to take the value '4712-01-01 00:00' as pseudo infinite date time i.e Applications supposed to render this value blank (eg BaaN 4c ).. but it does not do that when I update the column in question through linkedServer.. Any help is appriciated.. Thanks