When did expiration dates show up on products?

Expiration dates began appearing on products in the mid-20th century, with the practice becoming more common in the 1970s. Initially used for perishable goods like dairy and meat, they were adopted to improve food safety and consumer awareness. The U.S. government started encouraging the use of dating on food products during this time, leading to regulations that further standardized the practice. Today, expiration dates are widely used across various product categories, including pharmaceuticals and cosmetics.