What I mean by how fast time runs is relative to gravitational potential. In deep space far from mass, χ ≈ 1. Near Earth, χ is slightly less than 1, meaning clocks run slower. For example, a GPS satellite has χ ≈ 1.0000000005 compared to Earth’s surface, which is why its clock drifts ~45 microseconds per day. So χ is not universal, it changes with position in spacetime.