How Did Ancient Greece Use the Alarm Clock?

In ancient times, the concept of timekeeping and managing one’s daily routine was vastly different from what we know today. One of the most fascinating inventions of that era was the alarm clock.

Yes, you read it right! The alarm clock was not a modern-day invention but dates back to ancient Greece.

The First Alarm Clocks

Philosopher Plato is credited with inventing the first alarm clock in 428 B.C. It was a simple water clock that made a sound like a trumpet at a set time, alerting his students to attend their morning lectures.

The water clock had an internal tank filled with water that dripped into another container at a steady pace. Once enough water accumulated in the second container, it triggered the sound.

The Clepsydra

The clepsydra or water clock mentioned earlier was one of the most commonly used timekeeping devices in ancient Greece. It consisted of two containers- one on top and another below- connected by a tube with an orifice at its base. Water flowed from the top to bottom through this tube at a constant rate, marking time as it did so.

  • The Greek military: Ancient Greek soldiers used clepsydras as an alarm clock during battles.
  • The Athenian courts: In Athens, clepsydras were used to ensure that court sessions did not run over their allotted time.
  • The Olympics: At the Olympic games held in ancient Greece, clepsydras were used to measure event times.

The Hemeraion

Another type of alarm clock used by ancient Greeks was called Hemeraion or “daytime device.” It was mainly used by people who needed to wake up early, such as farmers and merchants.

This device consisted of a metal plate with nails placed at specific intervals. The plate was attached to a rope, and when the user wanted to wake up, they would release the rope, and the plate would fall to the ground, making a loud noise.


In conclusion, ancient Greeks used various methods to keep track of time and wake up early. The water clock or clepsydra was one of the most common timekeeping devices used in ancient Greece.

The Hemeraion was another type of alarm clock used by people who needed to wake up early in the morning. These ancient alarm clocks were simple yet effective and laid the foundation for modern-day alarm clocks that we use today.