We'd have a difficult time making use of certain foods that others might give us!
The DW checks every date code and will not use anything beyond it's date code. We even throw out food we just bought if it was past it's date code on the store shelf and it was too much hassle to return it to the store.
Also, we will not use certain foods if we have any suspicion that they may have been left out of the refrig too long - such as mayonaise products, egg products, peanut butter, cheese products, anything made from milk products, any kind of meat (processed or not, cooked or not), etc..