Assuming these people 10000 lightyears away from the black hole are also on a planet, their reference frame is almost the same as ours - the relative speed of d

Assuming these people 10000 lightyears away from the black hole are also on a planet, their reference frame is almost the same as ours - the relative speed of different planets is very small compared to the speed of light. So they'll agree on when 24000BC is.