For a charge function $Q\left(t\right)$, the instantaneous current at time $t$ is defined as

$I\left(t\right)=dQ/dt$

$I\left(t\right)=Q/t$

$I\left(t\right)=dt/dQ$

$I\left(t\right)={\int }_{}^{}Q\left(t\right)dt$