Bill Clinton actually said...
The modifications to the HTS made by paragraph (1) of this proclamation shall be effective with respect to articles that are: (i) imported on or after January 1, 1976, and (ii) entered, or withdrawn from warehouse for consumption, on or after 15 days after the date of publication of this proclamation in the Federal Register.
Context
Proclamation 6650—To Amend the Generalized System of Preferences and for Other Purposes
02/15/1994