Clocks are instruments that measure and show the time. For millennia, humans have been measuring time in various ways, some include tracking the movements of the sun with sundials, the use of water clocks, candle clocks, and hourglasses.

Our modern-day system of using a base-60 time system, that is a 60-minute and 60-second increment clock, dates back to 2,000 B.C. from ancient Sumeria.

The English word "clock" replaced the Old English word daegmael meaning "day measure." The word "clock" comes from the French word cloche meaning bell, which enters the language around the 14th century, around the time when clocks started hitting the mainstream.

Timeline for the Evolution of Timekeeping

The first mechanical clocks were invented in Europe around the start of the 14th century and were the standard timekeeping device until the pendulum clock was invented in 1656. There were many components that came together over time to give us the modern-day timekeeping pieces of today. Take a look at the evolution of those components and the cultures that helped develop them.

Sundials and Obelisks

Ancient Egyptian obelisks, constructed about 3,500 B.C., are also among the earliest shadow clocks. The oldest known sundial is from Egypt it dates back to around 1,500 B.C. Sundials have their origin in shadow clocks, which were the first devices used for measuring the parts of a day.

Greek Water Clocks

An early prototype of the alarm clock was invented by the Greeks around 250 BC. The Greeks built a water clock, called a clepsydra, where the rising waters would both keep time and eventually hit a mechanical bird that triggered an alarming whistle.

Clepsydras were more useful than sundials—they could be used indoors, during the night, and also when the sky was cloudy—although they were not as accurate. Greek water clocks became more accurate around 325 B.C., and they were adapted to have a face with an hour hand, making the reading of the clock more precise and convenient.

Candle Clocks

The earliest mention of candle clocks comes from a Chinese poem, written in 520 A.D. According to the poem, the graduated candle, with a measured rate of burn, was a means of determining the time at night. Similar candles were used in Japan until the early 10th century.

Hourglass

Hourglasses were the first dependable, reusable, reasonably accurate and easily constructed time-measurement devices. From the 15th century onwards, hourglasses were used primarily to tell time while at sea. An hourglass comprises two glass bulbs connected vertically by a narrow neck that allows a regulated trickle of material, usually sand, from the upper bulb to the lower one. Hourglasses are still in use today. They also were adopted for use in churches, industry and in cooking.

Monastery Clocks and Clock Towers

Church life and specifically monks calling others to prayer made timekeeping devices a necessity in daily life. The earliest medieval European clockmakers were Christian monks. The first recorded clock was built by the future Pope Sylvester II around the year 996. Much more sophisticated clocks and church clock towers were built by later monks. Peter Lightfoot, a 14th-century monk of Glastonbury, built one of the oldest clocks still in existence and continues to be in use at London's Science Museum.

Wrist Watch

In 1504, the first portable timepiece was invented in Nuremberg, Germany by Peter Henlein. It was not very accurate.

The first reported person to actually wear a watch on the wrist was the French mathematician and philosopher, Blaise Pascal (1623-1662). With a piece of string, he attached his pocket watch to his wrist.

Minute Hand

In 1577, Jost Burgi invented the minute hand. Burgi's invention was part of a clock made for Tycho Brahe, an astronomer who needed an accurate clock for stargazing.

Pendulum Clock

In 1656, the pendulum clock was invented by Christian Huygens, making clocks more accurate.

Mechanical Alarm Clock

The first mechanical alarm clock was invented by American Levi Hutchins of Concord, New Hampshire, in 1787. However, the ringing bell alarm on his clock could ring only at 4 a.m.

In 1876, a mechanical wind-up alarm clock that could be set for any time was patented (No. 183,725) by Seth E. Thomas.

Standard Time

Sir Sanford Fleming invented standard time in 1878. Standard time is the synchronization of clocks within a geographical area to a single time standard. It developed out of a need to aid weather forecasting and train travel. In the 20th century, the geographical areas were evenly spaced into time zones.

Quartz Clock

In 1927, Canadian-born Warren Marrison, a telecommunications engineer, was searching for reliable frequency standards at Bell Telephone Laboratories. He developed the first quartz clock, a highly accurate clock based on the regular vibrations of a quartz crystal in an electrical circuit.

Big Ben

In 1908, the Westclox Clock Company has issued a patent for the Big Ben alarm clock in London. The outstanding feature on this clock is the bell back, which completely envelops the inner case back and is an integral part of the case. The bell back provides a loud alarm.

Battery-Powered Clock

The Warren Clock Company was formed in 1912 and produced a new type of clock run by batteries, prior to that, clocks were either wound or run by weights.

Self-Winding Watch

Swiss inventor John Harwood developed the first self-winding watch in 1923.