Average Time Calculator

Two different questions share this name, and they need different arithmetic. Averaging lengths of time is ordinary addition and division, so enter a list of durations and you get the mean along with the total, median, range and spread. Averaging times of day is not, because the clock wraps: the plain mean of 23:00 and 01:00 is noon, the point furthest from both. For clock times this uses the circular mean, which gives midnight, and it reports how tightly the times cluster so you can tell when no average is meaningful at all.