Most of us take it for granted that we can always check the time—whether it's counting down to our next meeting or syncing up with someone across the world.

But how did people measure time in the past? And how accurate have we become? Let's take a look at five major tools used throughout history to measure time.

1. Sundials

The sundial is one of the oldest timekeeping tools in history. Even without any fancy equipment, we can estimate the time just by watching where the sun is in the sky—as long as it's a sunny day!

Around 1500 BC (or even earlier), people in ancient Egypt and Sumer created the first sundials to track time using the sun's shadow. Romans built large sundials in town squares, and wealthy folks carried mini versions. In fact, the oldest known portable sundial was found buried in volcanic ash in Italy from the eruption of Mount Vesuvius in 79 AD. It was shaped like a small chunk and fit right into a cup!

Sundials work by casting shadows from a stick or pointer (called a gnomon) onto a marked surface. Some sundials were fixed, while others adjusted for different seasons since daylight hours change. A well-made sundial could be accurate within an hour—and with care, even down to a minute!

The world's largest sundial is in Jaipur, India. It's 27 meters (88 feet) tall and accurate to within 2 seconds! Famous buildings like Taipei 101 and even the Luxor Obelisk in Paris also double as giant sundials.

2. Water Clocks

Sundials only work in daylight, and only when it's not cloudy. So people came up with another way: using water.

Water clocks go way back, too—one of the earliest was found in the tomb of Pharaoh Amenhotep I in Egypt, dated to 1500 BC. It was a tilted stone pot with a small hole at the bottom. As water slowly dripped out, the level dropped and marked time with lines inside.

To improve accuracy, some water clocks controlled the flow using pressure. But even then, changes in water temperature could throw off time by up to 30 minutes a day.

Some water clocks were also built for show—like ringing bells or moving statues. Plato even designed a water alarm clock around 427 BC. It whistled like a kettle when the water reached a certain level. The most complex water clock was shaped like an elephant and created by Al-Jazari in 1206.

Other creative tools included incense timers, sand hourglasses, and oil lamps—but they weren't much more accurate.

3. Mechanical Clocks

The next big leap in timekeeping came with mechanical clocks. These weren't based on flowing water or shifting shadows, but on controlled mechanical energy.

One of the earliest examples comes from Su Song, a Chinese scientist who built a 30-foot-tall water-powered mechanical clock in 1092. It could show not just the time, but the year and month too!

Later, in 1656, Dutch scientist Christiaan Huygens built the first pendulum clock (though many credit Galileo with the idea). It used a swinging pendulum to regulate the movement of gears. Early versions were accurate to within a minute a day, and later models got even better—down to 10 seconds a day.

4. Quartz Clocks

Quartz clocks came along in the 1920s and were a game-changer. They didn't need gears or springs. Instead, they used the vibrations of a quartz crystal to keep time.

When electricity passes through quartz, it vibrates at a super steady rate—perfect for ticking off seconds. The first quartz clocks, built in Japan, were only off by about 5 seconds a month.

Quartz clocks became the standard for wristwatches and wall clocks because they were affordable and much more accurate than mechanical ones. But there's still one tool that beats them all…

5. Atomic Clocks

The most precise clocks in the world today are atomic clocks. These don't rely on anything moving or flowing—they track the vibrations of atoms.

Specifically, they use cesium or hydrogen atoms, which naturally “tick” at an incredibly stable frequency. The official definition of one second today is based on the time it takes for a cesium atom to vibrate 9,192,631,770 times.

Modern atomic clocks are so precise that they only lose about one second every 300 million years! They're used in GPS satellites, space missions, and scientific research.

Time is always ticking

From sundials to atomic clocks, we've come a long way in tracking time. And even though we might not think about it much, every meeting we attend, every train we catch, and every timer we set owes a lot to thousands of years of timekeeping innovation.

Lykkers, next time you glance at the clock—whether it's digital or analog—take a moment to appreciate just how far we've come. Which of these ancient tools surprised you the most?

Let me know if you'd like a version suitable for kids or more pictures and diagrams added!