Babylonian mathematicians favored the number sixty, which is why minutes and hours use it.

The longer version

Scribes in Mesopotamia counted in base sixty, using it in trade, land measurement and astronomy. The system survives in how circles are divided and how minutes and hours are split, long after the civilisations that invented it disappeared. Tablets show multiplication tables built around the same base.

Twelve and sixty both divide neatly into many whole parts, which suits anyone dividing a quantity by hand. Scholarly works on astronomy written in Greek later carried these divisions westward, and medieval clockmakers inherited them already standard, so the numbers were never questioned. Decimal counting replaced it almost everywhere except the clock and the compass.

Where this entry sits

These facts wander through clocks, calendars, time zones, and the long human effort to measure passing hours. You will find leap years, odd month lengths, ancient sundials, and the reasons modern timekeeping works the way it does. The full list sits on the Time and Calendars page, where every entry is listed in order.