Mass-unit clock at rest

Mass-unit clock in motion

Length

L

$L^{\prime }=\frac{L}{\gamma }$

Light speed in the clock

c

$c^{\prime }=\sqrt{c^2-{\nu }^2}$

Size of a clock per time-unit

$s=c$

$s^{\prime }=\sqrt{c^2-{\nu }^2}$

Ticking time (reading)

t

$t^{\prime }=\frac{t}{\gamma }$

Length of clocks in ticking time t (space-time interval)

ct or st

$c{t}^{\prime }=c^{\prime }t=t\sqrt{c^2-{\nu }^2}$

Geometric average of time-unit

T₁T₂

${T^{\prime }}_1{T^{\prime }}_2=T_1{T}_2$

Arithmetic average of time-unit

$T=\frac{T_1+T_2}{2}$

$T^{\prime }=\frac{{T^{\prime }}_1+{T^{\prime }}_2}{2}=\gamma T$

Constant universal time value

$T\ast t$

$T^{\prime }\ast t^{\prime }=T\ast t$