We are on the internet right now, you could easily look this up:
As a general rule, butter that’s tightly wrapped and refrigerated should last anywhere from one to three months…
According to the USDA’s Food Safety and Inspection Service, “butter and margarine are safe at room temperature. However, if butter is left out at room temperature for several days, the flavor can turn rancid,
We are on the internet right now, you could easily look this up:
https://www.rd.com/article/does-butter-expire/
Maybe it’s salted butter that is used as a preservative.