History of Clocks

Have you ever stopped to wonder why clock hands sweep to the right? In a world full of arbitrary conventions, like driving on one side of the road or tying shoes a certain way, the direction of clock hands feels oddly inevitable. We call it “clockwise,” and the opposite “counterclockwise,” as if time itself has a preferred spin. Yet this simple motion hides a fascinating story that stretches back thousands of years, tying modern clocks to the ancient dance of the sun across the sky.

The answer begins with sundials, humanity’s first reliable clocks. Long before gears and springs, people told time by watching shadows. In the Northern Hemisphere, where most early civilizations with advanced timekeeping developed, the sun rises in the east, climbs to its peak in the south, and sets in the west. On a flat, horizontal sundial with its gnomon (the stick that casts the shadow) pointing north, the shadow moves in a steady arc from left to right as the day progresses. From the perspective of someone facing the dial, that shadow travels in what we now recognize as a clockwise direction.

Early sundials in ancient Egypt, Babylon, and Greece all followed this pattern. The shadow’s journey mirrored the apparent motion of the sun, making the system intuitive. When mechanical clocks appeared in Europe during the 13th and 14th centuries, inventors wanted their new devices to feel familiar. Monasteries needed precise bells for prayer times, and towns wanted public clocks that matched what people already understood from sundials. So clockmakers deliberately designed the hands to move in the same direction as sundial shadows: rightward, or clockwise.

Imagine being one of the first people to see a mechanical clock in a medieval town square. The towering device, with its single hand pointing to Roman numerals, would have seemed magical. Yet its motion was comforting because it echoed the reliable rhythm of the sun that everyone had watched since childhood. Reversing the direction would have confused people accustomed to centuries of sundial use.

What about the South?

What about the Southern Hemisphere? There, the sun’s path is reversed. It rises in the east, peaks in the north, and sets in the west, so a horizontal sundial’s shadow moves leftward, or counterclockwise from the viewer’s perspective. A few rare “southern sundials” do exist that run backward. However, by the time European explorers reached the southern continents, mechanical clocks were already standardized based on northern designs. Global trade and colonization spread the clockwise convention worldwide. Today, even in Australia or South Africa, clocks turn the same way as in London or New York.

Other theories have popped up over the years to explain the direction. Some claim it relates to right-handed dominance, since most people find it easier to turn screws or wind mechanisms clockwise. Others point to the motion of weaving looms or the way horses were mounted from the left. While these ideas are intriguing, historians agree they are secondary at best. The primary driver was the sundial precedent.

The term “clockwise” itself did not appear until the late Middle Ages, when clocks became common enough to need a word for their direction. Before that, people simply said “the way the sun goes” or “like a sundial.” Once coined, “clockwise” became the default, and “counterclockwise” the exception that proves the rule.

This seemingly trivial detail reveals how deeply history shapes everyday life. Every glance at a watch reinforces a decision made by medieval clockmakers in northern Europe. Analog clocks are slowly fading in the digital age, replaced by screens that merely display numbers. Yet the language lingers. We still talk about “turning the clock forward” for daylight saving or “working around the clock.” Races run counterclockwise on tracks, perhaps to balance the body’s natural tendencies against the clock’s direction.

Next time you check the time, pause for a second. Those hands are not just measuring minutes. They are tracing an ancient shadow cast by the sun, preserved through centuries of human ingenuity. The direction of time, it turns out, was decided long ago by the simple fact that most early clockmakers lived north of the equator and wanted their inventions to match the sky they knew.