I did some basic research on expiration dates or "best if sold by" dates. The articles I found contradict each other.
I can tell you this from my education and experience, Expiration dates are there to make you fear food beyond a certain date, Who benefits from expiration dates? In other words, follow the money. Who benefits economically? The manufacturers, the wholesalers and the stores and the landfills. You throw something away and then buy more so everyone profits, except you. The government gets more taxes, the manufacturer and everyone listed sells more product and makes more profits. That means they have a monetary interest in your throwing good food away. Greed pure and simple. You fear. They profit.
When they found and opened up King Tut's tomb, they found all kids of food stored so King Tut would have food to eat on his journey to the afterlife. Scientists took the wheat and used it to add disease resistance and drought tolerance to modern wheat. The wheat was viable and edible. According to the USDA, the wheat was centuries out of date and should have been thrown away, according to conventional wisdom.
According to what I have read, America throws away more food than any other country in the world (abut 50% of every grocery dollar is sent to the landfil.). AND that includes some third world countries where refrigeration is a luxury.
I have my kids over for dinner almost every Sunday. I made tacos and someone brought up expiration dates. Two of my children's spouces emphatically stated that out of date food was easy to tell by taste and was unsafe to eat. They wouldn't change their minds and were immune to any common sense arguements. After dinner, I dug the food wrappers out of the trash to look at the dates. The cheese was about 6 years out of date. The hamburger was 4 to 5 years out of date. The tortillas were almost one year out of date. No one complained about how the food tasted. Or its texture or anything else.
Eggs used to be stored out on the counter in stores before refrigeration became required. I used to go to a farmer that raised chickens for eggs. He never had refrigeration for his eggs until someone from the state (California) visited his shop and told him he couldn't sell eggs anymore until he put in refrigeration for his eggs. The result? He bought a refrigerated egg display case and the price of eggs went up 10 cents to 20 cents per dozen. I've raised chickens before. A hen will sit on her eggs and keep them viable until she has enough eggs in her nest to incubate them so they will hatch them all at one time. A hen willl lay almost one egg per day. The chickens I had wanted to have a clutch of a dozen eggs. It usually takes 14 to 16 days for the hen to get a dozen eggs in her nest. According to our government, those eggs are unusuable and should be thrown away because they are no good. But that "dumb cluck" sitting on those eggs knows better than all of the PHD's in the USDA and with patience and perserverence will hatch a dozen chicks.
Before the lawyers got involved, I would bargain with the dairy managers for their dairy items that were either out of date or going out of date and them I'd take them home and feed my family. Adjusting for inflation to today's prices, I'd pay 10 cents for yogurt, 50 cents per pound for cheese, 50 per gallon for milk and 25 cents per container for heavy cream and cottage cheese. If they had enough heavy cream, and I could get it cheap enough I would churn my own butter.
I have used canned tuna that was 5 to 8 years out of date. I have used Rotel that was three years out of date. When I go to the store to buy cereal, I look at the expiration dates and I know if the oldest expiration date is 9 months away, that the cereal will do fine on my shelf for at least 18 months.
I check the dates on products when I use them. I smell them and some times taste them. If it smells ok and tastes ok, then I use it.
Of course if money is no object, then throw away and spend like you don't really care. AND remember the wheat in King Tut's tomb that was CENTURIES out of date according to the government.
Good luck to you and yours.