The way I know Clinique butter depends on the production date and shelf life. The production date of Clinique butter mainly depends on the product batch number. The first letter of Clinique product batch number stands for the place of origin. Any letter A-Z indicates different places of origin. The second batch number of Clinique products represents the production month, and the third batch number of Clinique products represents the production year. The shelf life is marked on the bottle body of the product, and the shelf life is generally 24 months after opening the lid.