One of my very favorite sci-fi authors, Robert A Heinlein, wrote a haunting short story about a scientist, Pinero, who discovered a means to literally and accurately determine one's date of death. Called "Life-Line," it was RAH's very first published story.
Today, actuaries and underwriters use "Mortality Tables" to guesstimate how long one might live. These are based not on the length of one's "world line," but the Law of Large Numbers. Obviously, an underwriter has no idea when you are going to die, just the likelihood of it in a certain timeframe.
Now, the folks at The Quiet Company have come up with their own version of Dr Pinero's device. Called the "LifeSpan Calculator," one answers a series of questions, and the LSC calculates how many years one has left on this mortal coil. It even offers suggestions on how to improve that number. It took me only a few moments to calculate my likely lifespan, and the questions were quite user-friendly.
Definitely worth a click.