bavirisetty, check out this link (it if for DB2 LUW V9.7 since you didn't mention DB2 version or operating system) for
Scalar functions - IBM DB2 9.7 for Linux, UNIX, and Windows
Functions are your friends. read up on them and remember them when you need to do something. They are very useful.
Specifically, look up the TIMESTAMP function.
TIMESTAMP('2009-10-04', '00.00.00')
There are other ways to accomplish the same task.