In the UK, and I guess there are similarities elsewhere, food dates come in two forms.
"Best before" is product quality information. "Use by" is product safety information. If a product says "best before mm/yyyy" you can use the product after that. There'll be a gradual deterioration in quality. But it may well be safe for years after the date (depending how it's stored and whether the packaging stays in shape).
"Use by" means you risk illness if you eat it after the date. Obviously there's a bit of a safety margin built in, and some people are at much higher risk of illness than others.
"Best before" is product quality information. "Use by" is product safety information. If a product says "best before mm/yyyy" you can use the product after that. There'll be a gradual deterioration in quality. But it may well be safe for years after the date (depending how it's stored and whether the packaging stays in shape).
"Use by" means you risk illness if you eat it after the date. Obviously there's a bit of a safety margin built in, and some people are at much higher risk of illness than others.