Humans have always needed to sleep as this is an important time to recharge the body and rest so people can be productive during the day, so as long as man kind has lived on the planet there has always been a method that people choose to wake them up on time in the morning. Perhaps in the earliest of days people who rise when the sun rose, or when the birds started singing, however as human beings developed technologies have come about which have helped them wake up in the morning.
One of the first types of alarm clocks ever used was by the Greek philosopher Plato who lived in and around 350 BC, he developed a clock powered by water which at a certain time would sound a water organ, this primitive device would be used to remind Plato of pre determined times and was one of the first examples of a device to raise an alarm at a specified time. As time progressed the water alarm clock was further developed and even the Roman senator Cassiodorus in 550 BC used this device for an alarm for his soldiers.
Similar devices were not only developed in Europe by across the globe in China, where in around 700 AC a Buddhist monk developed a striking clock which would sound an alarm at certain time intervals. As well as alarm clocks being developed in Europe and China, there were also examples of clocks with sounding mechanisms also being developed in the Middle East, many of these devices were water powered and were used to remind people of prayer times.
Some of the next major developments in alarm clock design came in Western Europe in the 14th Century, when the common clock towers sprouting up around medieval Europe could be set to chime at a certain time of the day, and one of the first recorded devices was described by Dante Alighieri in 1319. Further examples of chiming clock towers were developed throughout Europe with famous examples of the St Marks Clock tower in Venice which could make a sound at preset times, this dates back to 1493 and set the precedence with clock design, many of these clocks used a hammer on a bell to describe a pre set time.
As the number of clocks in western Europe grew the use of alarms increased as the mechanically mechanisms used to control the timings also grew in accuracy as well as reliability. The first mechanical alarm clock was invented by Levi Hutchins of Concord, New Hampshire, in 1787. However, the ringing bell alarm on his clock could ring only at 4 am. On October 24, 1876 a mechanical wind-up alarm clock that could be set for any time was patented (#183,725) by Seth E Thomas. Many used cogs and wheels for the timing mechanisms, and a hammer on a bell to mark the time of the alarm, and by the 1850’s the French inventor Antoine Redier invested an adjustable mechanical alarm clock which could determine the time that the alarm sound went off.
The first radio alarm clock was invented by James F. Reynolds, in the 1940s and another design was also invented by Paul L Schroth Sr.
Modern digital alarm clocks where invented in the 1970’s/80’ and typically feature a radio alarm function and/or beeping or buzzing alarm, allowing a sleeper to awaken to music or news radio rather than harsh noise. Most also offer a "snooze button", a large button on the top that stops the alarm and sets it to ring again at a short time later, most commonly nine minutes. Some alarm clocks also have a "sleep" button, which turns the radio on for a set amount of time (usually around one hour). This is useful for people who like to fall asleep with the radio on. Since the invention of digital alarms they have become increasing popular with large LED or LCD displays to tell the time.