Gravitational Time Dilation: The proper time measured by a clock moving with 3-velocity vᵃ= dxᵃ/dt (a=1,2,3.) in a spacetime with metric gᵤᵥ (u,v=0,1,2,3.) is given by:
dτ = √(- c⁻ ² gᵤᵥdxᵘdxᵛ)·dt= √(-g₀₀ - 2gₐ₀ dxᵃ vᵃ/c - v²/c²)·dt. Where v²=gₐₑvᵃvᵉ (a,e=1,2,3.).
For v=0, dτ =√(-g₀₀)·dt...