Vierordt's law

Karl von Vierordt in 1868 was the first to record a law of time perception which relates perceived duration to actual duration over different interval magnitudes, and according to task complexity. It states that, retrospectively, "short" intervals of time (e.g., 10 seconds) tend to be overestimated, and "long" intervals of time tend to be underestimated. The other major paradigm of time estimation methodology measures time prospectively.

Modern research suggests that "Vierordt’s law is caused by an unnatural yet widely used experimental protocol".