How to Calculate Expiration Dates and Shelf Life: The Math Behind ‘Best By’ Labels
Milk printed “Best By Aug 12” is usually still safe on Aug 15; canned beans stamped “2027” are often fine in 2030. The dates on packaging are calculation outputs, not cliff edges — and understanding how manufacturers derive them turns a confusing label into a usable guide. Here is the arithmetic behind shelf-life dating, plus …