Why are there 60 seconds in a minute? Blame Babylon

By Sam Arkwell · published September 8, 2026

The metric revolution conquered almost everything: meters replaced feet, kilograms replaced pounds, currencies went to hundredths. One holdout ticks on your wrist as if nothing happened: 60 seconds, 60 minutes, 24 hours, the exact arithmetic of Babylonian scribes four thousand years ago. This is the story of the oldest standard you use every day, why it beat the decimal system fair and square, and the one time a country tried to kill it.

Counting on finger bones

The trail leads to Mesopotamia, around 2000 BC. The Babylonians, inheriting from Sumer, ran their mathematics in base 60: thousands of surviving clay tablets count in bundles of sixty the way we count in tens. The likely origin is charmingly anatomical: using your thumb, you can count the 12 finger joints on one hand, then tally multiples on the 5 fingers of the other. Twelve times five is sixty, a pocket calculator made of bone.

Babylon’s astronomers, the finest of the ancient world, projected the system onto the sky: a circle of 360 degrees, roughly one per day of the Sun’s yearly journey. Centuries later Greek astronomers, Hipparchus and then Ptolemy, borrowed the toolkit and sliced time with it. The hour was divided into 60 partes minutae primae, the “first small parts”, our minutes, and each of those into 60 partes minutae secundae, the “second small parts”. The word second is, literally, a fossil of that phrase.

The 24-hour frame came from Egypt: 12 daylight hours on sundials, 12 night hours tracked by the rising of stars, base 12 all the way. Greek astronomy glued the Egyptian day to the Babylonian subdivisions, and the bundle has run uninterrupted ever since, straight through to the online clock in your browser tab.

The killer argument: divisibility

Why did this antique survive when everything else went decimal? Because 60 is objectively excellent at the one thing a time system must do: splitting evenly. Sixty divides cleanly by 2, 3, 4, 5, 6, 10, 12, 15, 20 and 30. One hundred fails at 3, 6 and 12. Half an hour, a quarter hour, twenty minutes, ten, five: every everyday fraction of time lands on a whole number. Base 60 is a compromise-free fraction machine, which is exactly why the Babylonians, who did astronomy by hand, chose it.

The counterexample ran its experiment in France. In 1793 the revolutionary government decreed decimal time: 10-hour days, 100-minute hours, 100-second minutes, midnight at ten o’clock. Watchmakers produced beautiful dual-dial pieces; the public produced a collective shrug. Replacing every clock in the nation to make a third of an hour equal 33.33 minutes convinced no one, and the scheme was shelved within two years, the only major metric reform that ever surrendered. The meter went on to conquer the planet; decimal time went to the museum.

There is a quiet lesson in that: standards survive on usefulness plus installed base. Base 60 had both, four thousand years of habit and a genuine mathematical edge. Very few accidents of history can claim they also happened to be the right answer.

The oldest standard still on duty

Today the Babylonian bundle may be the oldest technical standard in continuous service. Its angular twin thrives too: 360 degrees, arcminutes and arcseconds still grid every nautical chart and star catalogue. Empires fell, cuneiform died, but every lap of your stopwatch counts the Mesopotamian way.

And the story ends with a flourish of precision. The second, great-grandchild of clay tablets, is now the most exactly defined unit in all of physics, pinned to 9,192,631,770 vibrations of a cesium atom. We measure a Babylonian sixtieth of a sixtieth of an hour to fourteen decimal places, on atomic clocks that drift less than a second per hundred million years.

So the next time a timer counts down its neat sixties, or you wonder why the hands run clockwise, spare a thought for the scribes of Babylon: they counted on their finger bones, and the whole world still keeps their beat.

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