Definition: Event-time versus history calibration

For distinct $t_k$:

1. exact event-time calibration at a fixed event $e$ means $p_k>0\Rightarrow t_k=T(e)$;

2. history calibration means that a declared map $\kappa$ satisfies $T(\kappa (k))=t_k$.

The latter need not identify the labelled event with the readout event.