喝牛奶的时候看着包装上的保质期，突然想到还没弄清楚这几种日期区别，google了一下，结果和我预想的一致："Use by"是最后食用期限，过后就变质，会对人体健康有影响。"Display until"是给商家看的，表示在这个期限之后就要把商品撤下货架。"Best before"是指过了这个期限后口感和味道可能会发生变化，但依旧可以安全食用。除了鸡蛋，鸡蛋的保质期虽然用的是"Best before"，但是由于鸡蛋里含有沙门氏菌，在保质期过后会有繁殖的可能，因此鸡蛋不能在"Best before"的日期后食用。

我赶紧看了一下家里还剩的一盒鸡蛋，"Best before: 28 DEC"
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以下是关于三种日期含义的原文:

'Use by' means exactly that. You shouldn't use any food or drink after the end of the 'use by' date shown on the label. Even if it looks and smells fine, using it after this date could put your health at risk and cause food poisoning.

You will usually find a 'use by' date on food that goes off quickly, such as milk, soft cheese, ready-prepared salads and smoked fish.

It's also important to follow any storage instructions given on food labels, otherwise the food might not last until the 'use by' date. Usually food with a 'use by' date needs to be kept in the fridge.

'Best before' dates are usually used on foods that last longer, such as frozen, dried or canned foods. It should be safe to eat food after the 'best before' date, but the food will no longer be at its best. After this date, the food might begin to lose its flavour and texture.

However, you shouldn't eat eggs after the 'best before' date. This is because eggs can contain salmonella bacteria, which could start to multiply after this date.

Some food labels also give instructions such as 'eat within a week of opening' and it's important to follow these instructions. But remember, if the 'use by' date is tomorrow, then you must use the food by the end of tomorrow, even if the label says 'eat within a week of opening' and you have only opened the food today.

'Display until' and 'sell by' dates are instructions for shop staff to tell them when they should take a product off the shelves.

via :eatwell.gov.uk