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Last modified date

Jan 9, 2023

15 Timekeeping Devices and Inventions in History

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Alexandra Martin

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11 min

Last modified date

January 9, 2023

You heard the aphorism, “Time is money,” that Benjamin Franklin famously stated in “Advice to a Young Tradesman” in 1748.

It’s the same Benjamin Franklin who outlined tips on being productive and boasted a daily schedule that’s still efficient centuries later.

The link between time and money is so embedded in our modern culture that it made me wonder if we were the only ones to obsess over productivity and profitability.

So, I endeavored to find out whether «Time is Money» is exclusive to the modern man. I’ll spill the beans—it’s not.

So who were the first to track their time? We’ll trace back to the Babylonians, Egyptians, ancient China, and Antiquity, traverse to the Middle Ages and Renaissance, and lastly, touch upon the 20th century.

Each period with its inventions and breakthroughs gives us a better grasp of what we today understand as “objective time.”

Note: This article focuses on measurable, objective time. If you’re interested in subjective time, namely how fast or slow we perceive time to be flowing, stay tuned for my upcoming article on subjective time.

This article covers time-tracking antiques—and antics—and how people have been productive and profitable by tracking their time since time immemorial. All puns intended.

Time tracking was written in the stars

Pun aside, the first time-tracking method was not up to fate but somewhat inevitable and necessary since early societies needed to be organized.

For instance, the Egyptians developed the 24-hour day thanks to a mix of astronomy and math.

Egyptians used a duodecimal (base 12) number system, which means that they would use their three finger joints of the four fingers—excluding the thumb—to count to (multiples of) twelve.

They divided the sky into 36 groups of stars, noticed how stars were positioned in relation to each other, and ultimately developed the 365-day solar calendar. They also noted twelve lunar cycles, where, for instance, the Sirius star would mark the New Year.

constellation map

A simple constellation map. Source: Pablo Carlos Budassi, Wikicommons. 

Also, the Egyptians used elaborate sundials and water clocks (which we’ll cover in a minute) to tell the time.

How did we get hours, minutes, and seconds?

First, we’ll cover how we got the division of time. Let’s start with some quick Babylonian mathematics.

Piggybacking on the Sumerians, the Babylonians used a sexagesimal (base 60) number system, which is far more complex than the decimal (base 10) used by the Chinese or duodecimal (base 12) of the Egyptians.

Counting in base 60 is convenient since it has 12 factors (namely, it can be divided by twelve numbers, 1, 2, 3, 4, 5, 6, 10, 12, 15, 20, 30, and 60) and three prime numbers (2, 3, 5).

Simply put, one hour (60 minutes) can be divided evenly into sections of 30 minutes, 20 minutes, 15 minutes, 12 minutes, 10 minutes, 6 minutes, 5 minutes, 4 minutes, 3 minutes, 2 minutes, and 1 minute.

Suppose one hour had been 100 minutes (in base 10, for example); it wouldn’t have allowed such minute division—pun intended.

Yet it wasn’t until the Greeks (circa A.D. 150) that we got the time divisions we use today. In his astronomical treatise, Claudius Ptolemy subdivided each of the 360 degrees of latitude and longitude into smaller segments of 60 parts called ‘partes minutae primae’ [the ‘minute’], which were again subdivided into 60 smaller parts called ‘partes minutiae secundae.’ The ‘second minute’ became ‘the second’ for short.

Nevertheless, people did not need such detailed timekeeping until the Renaissance with the advent of the mechanical clock (more on that later). Time was kept and divided into halves, thirds, and quarters for everyday activities.

Leaving math and astronomy aside, let’s focus on timekeeping devices throughout millennia:

15 Timekeeping devices and inventions

1. The sundial (or ‘sun’ clock)

Known as the sun clock, the sundial uses sunlight to cast a shadow over the ‘gnomon’ (pointer) and onto the dial, which is a flat, numbered plate like so:


This sundial gives the local time based on specific longitudes. Source: Harvard University. 

The Babylonians invented the sundial, and the Egyptians refined it. The Greeks, and later the Romans, adopted it for public use in squares.

Before sundials, obelisks and even the Stonehenge were used as ‘shadow’ clocks to measure the sun’s position and tell whether it was morning or noon.

Fun fact: Is your “clockwise” right?

Did you know that the sun casts shadows differently in the Northern and Southern Hemisphere? In the Northern Hemisphere, the shadow moves from north to east, to south, to west, which is how we got the notion of ‘clockwise.’ In the Southern Hemisphere, the shadow moves in the opposite direction, thus ‘counterclockwise.’ Had societies from the Southern Hemisphere developed the sundial, we’d probably be telling ‘clockwise’ the other way around.

Sundials haven’t lost their appeal. Julien Coyne invented a digital sundial in 2015. It displays time in increments of 20 minutes.

2. The incense clock (or ‘fire’ clock)

Probably invented in India, this timekeeping device was used in temples and the Chinese royal palace.

Burning incense sticks would gradually burn through threads placed on a trough, which triggered the metal weights to fall at regular intervals, causing a ‘clang’ to act as a time signal, like so:

incense clock fire clock

Early 19th-century incense clock. Source: Royal Museums Greenwich.

Now that’s a cool alarm clock. Also, incense sticks of various lengths were used to measure minutes, hours, and even days.

3. The candle clock

The ancient Chinese focused on the little details, the minutiae (pun intended) of daily life, so far as to name each hour of the day.

They employed 15 units of time or for daylight, correlated to each hour from 06:00 to 20:00 on the 24-hour clock. They had words for dawn [6 am], morning light, daybreak, early meal, feast meal, before noon, noon, short shadow, evening (‘evening mealtime’), long shadow, high setting, lower setting, sunset, twilight, and rest time [8 pm].

So, a simple question like “What time is it?” would have been rendered “Which daylight is it?”. Imagine getting “It’s long shadow” as an answer.

But what about during nighttime? Besides incense clocks to keep track of time, the ancient Chinese used marked candles to tell the time by engraving the length of a candle with evenly spaced markings. Though an ancient technology, candle clocks were used in medieval churches across Europe.

Also, one could use a candle clock as an alarm clock by inserting nails into the wax; when the wax burnt down to the nail, the nail would fall onto a metal plate, making a loud noise.

candle clocks

Modern sketch illustrating various candle clocks. Source: Alhontess, Shutterstock.

4. The clepsydra (or ‘water’ clock)

By far the most accurate timekeeping device invented in the ancient world was the clepsydra (water clock). The clepsydra is the nocturnal counterpart of the sundial, designed to measure hours at night accurately thanks to the laws of physics, namely Torricelli’s Law.

The ‘clepsydra’ (Greek for ‘water thief)’ is attributed to the Babylonians (1600 BC) and Egyptians (1400 BC), who inscribed markings onto bowls for the 12 hours of day or night.

The simplest water clock was an apparatus that allowed water from a wide vessel to slowly drip through a small hole at the bottom into another vessel placed below it.

water clock clepsydra

Reconstruction of a 5th-century clepsydra hosted by the Ancient Agora Museum in Athens. Source: Agora Publication.

Collections of clay tablets prove that Babylonians used water clocks as a time-tracking method to ensure proper payment of day and night guards and attendance keeping. Indeed, profit drives innovation.

Water clocks in ancient China continued to progress into more sophisticated and accurate timepieces. Early water clocks were correct to within 15 minutes each day. Water clocks were used in every office throughout the empire since officials were required to note the date and time of all incoming and outgoing correspondence. This time-clocking system is like a timesheet.

Clepsydrae were used extensively in Greek and Roman courts of law for time efficiency. Indeed, they wanted to ensure that proceedings moved steadily and that speakers did not go over their allotted time.

For high-stakes cases like the death penalty by crucifixion, beheading, and live burial, the water clock would be filled to the brim in contrast to only partially for minor cases, like petty crimes or misdemeanors. Like a stopwatch, the water flow was stopped with wax in case of interruptions or if extra time was needed to examine new evidence.

Fun fact: Plato is said to have invented an alarm clock based on the clepsydra that used lead balls falling onto a copper platter to wake his students up.

5. The hourglass (the ‘sand’ clock)

An hourglass (or sandglass or sand timer) is a timekeeping device consisting of two glass bulbs connected by a narrow neck, through which sand flows from one bulb to the other. The origin of the idiom “the sands of time,” a metaphor for the passage of time, stresses that the human lifespan is limited.

Although its origins are unclear, dating back to Antiquity in 350 A.D, the hourglass was immensely popular in Europe during the Middle Ages thanks to increasing needs to keep track of time during church services, for maritime travel, to keep track of time spent on breaks from manual labor, and cooking time.

As clock technology advanced thanks to the mechanical clock, hourglasses became less useful around the Renaissance. However, hourglasses are still used today in cookery and leisure time, namely board games.

3D hourglass

Hourglasses are popular pieces of decoration. Source: Kirill Khlybov, Artstation. 

6. The mechanical clock

The mechanical clock was invented in England in 1275 by an Italian monk. The earliest records indicate that a mechanical clock was working in a Bedfordshire church in 1283.

Mechanical clocks were the first time-telling instrument that did not depend on daylight or resources (water, wax, incense, sand, etc.) to keep time. The clockwork was set in motion by cogwheels pulled by a weight, whose force was regulated by an escapement, a mechanical device that stops the fall of the weight at regular intervals.

Soon, mechanical clocks became popular in Europe, installed in church towers and town halls. Hearing the bells chime in tower clocks, belfries, and bell towers was almost synonymous with ‘church time’—a time for worship.

7. The astronomical clock

Inspired by Greek planetaria and orrery (mechanical models of the solar system), the astronomical clock (or the horologium, or orloj) is made of dials that, besides telling time, display astronomical information with great accuracy.

The standard astronomical clock would tell the positions of the sun and moon, zodiacal constellations, movements of planets, etc.

Some astronomical clocks include a tide clock, keeping track of the moon’s motion around the Earth.

The oldest working astronomical clock (and the third oldest in the world) was built in 1410 in Prague.

astronomic clock Prague

The twelve Apostles are set in motion every hour at the doors above the clock. The four figurines by the astrolabe represent Vanity, Greed, Death, and Lust. Source: Jack Hunter, Unsplash. 

Prototypes of astronomical clocks include the Greek Antikythera, the hydro-mechanical astronomical clock with a waterwheel steelyard clepsydra invented by Chinese polymath Su Song in 1092, and the 14-century astrolabic clock by Ibn al-Shatir, who worked as a religious timekeeper, astronomer, and clockmaker.

The Greek Antikythera Machine, an ancient analogue computer dated 2nd century BC, was used for complex astronomy calculations.

8. The spring clock

With the invention of the mainspring leading to the invention of the alarm clock, mechanical clocks were finally more reliable. That’s because up until the 1500s, mechanical clocks lost or gained up to two hours each day. In addition, the mainspring helped make the mechanism smaller so people could purchase clock models for their homes.

Doctors could determine pulse rates, scientists could make more accurate time measurements, navigators could better determine their position at sea, and tradesmen could be more profitable. Telling time shifted from ‘church time,’ the time perception needed for religious services, to ‘merchant’s time,’ namely the need to tell time for productivity and profitability.

9. The portable watch

Thanks to the mainspring, the first small-sized watch was invented in 1510 by Peter Henlein, a German horologist and watchmaker.

portable watch pocket watch

Heinlein’s oldest pocket watch was small enough to be carried in a pouch or purse. Source: The German National Museum, Nürnberg. 

The first model was a timepiece worn around the neck as a pendant. Jewelers made portable watches become luxury items transported in pouches and purses. By 1574, the first pocket watch was invented, featuring Saint George slaying the Dragon.

In 1812, commissioned by the Queen of Naples, Breguet redesigned the portable watch to fit on a wrist, hence the name ‘wristwatch.’

10. The pendulum clock

A pendulum clock is a timekeeping instrument that uses a pendulum, a weight swinging back and forth in a precise time interval.

Christiaan Huygens, a Dutch polymath, made a remarkable breakthrough in horology by expanding on Galileo’s studies of motion, namely the pendulum effect. In 1656, Huygens prototyped the first pendulum clock that was correct to within a minute a day. A year later, he patented his timepiece.

The pendulum clock was the most reliable timepiece at the time. By 1670 William Clement of London refined the pendulum clock to be true within a second a day. By 1889, Sigmund Riefler’s pendulum clock kept time to within 0.01 seconds a day.

This breakthrough refined tower clocks – Westminster’s Big Ben was nothing short of teamwork and great effort. Designed by horologist Sir Edmund Beckett, astronomer royal Sir Goerge Airy, and clockmaker Edward Dent in 1851, the bell in Elizabeth’s Tower weighs 15.1 tons and had unprecedented accuracy due to the clock’s pendulum, which is accurate to within two seconds per week.

big ben pendulum clock

The £80m renovation project of the Big Ben was finished in November 2021. Source: Nick Fewings, Unsplash.

11. The stopwatch

The first stopwatch, a pocket watch that was stopped by operating a lever, was invented in 1695 by horologist Samuel Watson to better assist surgeons and doctors.

In 1776, Jean-Moyes Pouzai endeavored to design a clock that recorded the passage of time on paper—calling it a “chronograph”—for his astronomy research.

In 1822, clockmaker Nicholas Mathieu Rieussec expanded on the chronograph at the order of King Louis XVIII, who needed accurate time tracking for horse racing.

In 1831, an Austrian employee at Breguet, Joseph Thaddeus Winnerl, invented the split-second mechanism similar to today’s analog stopwatch.

analogue stopwatch

Mechanical stopwatch. Source: Stanislav, Unsplash. 

In 1930, the Breitling Watch Company patented the first stopwatch. The bottom line is that, in history, there have been many practical uses for the stopwatch, from entertainment and sporting events to military research and industrial productivity.

12. The repeater

Samuel Watson invented the repeater in 1710, which gave audible cues at specific time points.

For instance, a five-minute repeater strikes the hour and then the number of five-minute periods since the hour. It was a great invention for the visually impaired who needed an accurate time-telling device.

Fun fact: a quirky alternative was the ‘dumb repeater’ that used vibrations to tell time quietly in meetings and concerts.

13. The egg timer (or kitchen timer)

Traditionally, an egg timer is a simple 3-minute hourglass used to time the cooking of boiled eggs. In time, egg timers used mechanical clockwork or digital displays for multiple uses in the kitchen, coming in different shapes and sizes.

The tomato-shaped mechanical clockwork inspired one of the most popular time-tracking methods, the Pomodoro technique, credited to entrepreneur Francesco Cirillo in the late 1980s.

Nowadays, Pomodoro apps are used for various personal and professional activities, not just for cooking.

egg timer

A 55-minute mechanical egg timer. Source: Debby Hudson, Unsplash.

14. The electric clock

The first experimental electric clock was built in 1840 by Alexander Bain of Scotland. The electric clock used a battery driven by a spring and pendulum to give electrical impulses.

A year later, along with John Barwise, he worked on a timepiece driven by an electromagnetic pendulum and electric current to keep time.

By the 1930s, electric clocks started replacing mechanical clocks as the most popular timekeeping devices.

Electro-mechanical clocks like the flip clock (known as the Plato clock) that featured a split-flap display gained popularity in the 60s. Take, for instance, Solari di Udine’s 1965 award-winning Cifra 3:

flip clock

The Cifra 3 digital flip clock won the Compasso d’Oro prize for industrial design and is on display at the Museum of Modern Art (MoMA) in New York. Source: WikiCommons.

The invention of LCD (short for liquid-crystal display) in 1968 brought a new era for clocks and watches. LCD battery-operated clocks became more prevalent in the 70s and have not lost popularity since.

Note: an electric clock is not the same as a digital clock. ‘Electronic’ means that the clockwork is powered by AC, while ‘digital’ refers to the type of display. Though rare, there are mechanical clocks with digital displays. Conversely, there are many electric clocks with analog displays, for example, battery-powered wristwatches.

15. The atomic clock

Invented in 1948 by Harold Lyons and his colleagues at the U.S. National Bureau of Standards (now National Institute of Standards and Technology, or ‘NIST’), the first atomic clock used the ammonia molecule as the source of vibrations, laying the groundwork for new technologies, like cell phones and GPS.

first atomic clock

Maintenance of the ‘clockwork’ of the first ever atomic clock at the NIST. Source: Engineering and Technology History Wiki.

Later developments included the cesium clock (1955) built by the National Physical Laboratory in England, costing $20,000 a timepiece, the rubidium atomic clock—a more affordable alternative—and the ultracold strontium apparatus built at the Joint Institute for Laboratory Astrophysics (JILA) in 2008.

The strontium atomic clock is the most accurate timepiece ever invented by mankind, as it uses laser beams and quantum gas to measure vibrations. This optical atomic clock lags 1 second every 15 billion years—I sure won’t hold my breath to see that happening.

strontium atomic clock

JILA’s 3D quantum gas atomic clock ‘ticks’ blue light. Source: G. Edward Marti, JILA.


I hope this article conveys that time-tracking and time-keeping did not happen by chance. Polymaths and inventors tinkered with timepieces and time-keeping automata across millennia to ensure constant technological progress.

Indeed, every society employed variations of these inventions to keep track of time, either for worship (church time) or profit (merchant’s time).

Luckily for us living in the 21st century, telling and keeping time has never been easier. Imagine burning candles to keep track of your creative projects in 2022 or billing your clients consultancy fees based on water vessels.

Thankfully, digital tools and time-tracking software ensure you don’t have to stress over the accuracy of objective time. For starters, use Paymo’s automatic time tracker to experience first-hand how to get paid fairly for your hours.

First published on December 15, 2022.

Alexandra Martin


Drawing from a background in cognitive linguistics and armed with 10+ years of content writing experience, Alexandra Martin combines her expertise with a newfound interest in productivity and project management. In her spare time, she dabbles in all things creative.

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