I had some deli style garlic butter that sat in my fridge for a year or more. It was still probably okay to eat, but it was way past the date on the container, so I decided to get rid of it.
It was a sizeable chunk about 3" square by 1" deep in a plastic container. I wanted to recycle the container, so I just threw the chunk of butter out in the back yard. I figured critters or the weather would soon take care of it. That was about a month ago. Today, it is still there.