I'm looking for a book or short story about mining time from before the mid 1980s

In the book, it is discovered that people can "mine for time" that then can be used to extend their own lives. However, it is discovered that the time you mine is someone else's, and you are actually taking away from their life-expectancy. Anybody familiar with it. My mom read it in high school in the mid 1980s, so it's gotta be from then or before.