The measurement of change inherently signifies the measurement of relative change in a physical event. When events involve time, the relevance lies in the event's change itself and not in the observer, as the observer does not partake in the physical transformation occurring within the event.

At the onset of the measurement, two synchronized clocks—one belonging to the observer and the other to the observed—are calibrated to the same time scale, with both initially positioned within the same reference frame. When the event begins at time t₀, the observed entity separates from the observer, undergoes acceleration, and reaches a specified velocity. Once the event concludes, the observed entity re-joins the reference frame of the observer, and the elapsed time is immediately measured within this unified reference frame.

In this process, the time dimension originates from and returns to a common point for both clocks. However, the elapsed time on the observer's reference clock (t - t₀) is greater than that on the observed clock (t′−t₀), such that t - t₀ > t′−t₀ or equivalently, t