$t^{\prime }=\gamma \left(t-\overrightarrow{\beta }\overrightarrow{r}/c_0\right)$

where $t$ is local time and $\overrightarrow{r}$ is the three-dimensional position vector of an event observed in the rest frame

Note 1 to entry: In the special case that the X-axis of frame S is parallel with X′ axis of frame S′ and the direction of movement of frames is parallel to the X-axis, $t^{\prime }=\gamma \left(t-vx/c_0{}^2\right)$.

Note 2 to entry: The coherent SI unit of relativistic time is second, s.