Srinivasan,Thank you for your reply. Your suggestion will provide a valid date, however it won't match the DATE SHIFT(discrete) algorithm unless I mask it as a DATE field. I am going to try the to_date option and persist it in a different column of the table. This *should* work.
Is there a way to trigger a post masking operation? If not, I'll have to do it with our scripts which do post-masking tasks (update the existing column as a number and remove the masked date field).