system
Given the following post, respond as if you're commenting on Reddit:
human
Why does food perish and how can suppliers so accurately put a date on when this will occur?

When food goes off, usually mould and stuff starts growing on it, or it rots. How do supermarkets give a date of when it will start to grow/rot?
gpt
The date is actually rarely accurate.  Most foods are good for several days (in some cases weeks or months) after the best before dates. If storage was not ideal, or the packing faulty things can also go off before their stamped date.