With time travel you could pull off last minute injunctions on people who were going to die anyways. Think of it as Prisoner of Azkaban escapes, except instead of preventing deaths you just make use of them.

I think it'd work best as a mirror to the organ donor / organ recipient list. You sign up, and when you would normally have a catastrophic broomstick accident (or whatever), you instead have a couple medical professionals and the horcrux maker visit you 5 minutes before your appointed time.