Alarm Clocks are the being used from long time ago. The Sundirl was the first alarm clock which were used. It is simple shadow clock that refined into the sundial in 1500 BC Egypt. Falling weight system clocks were used in pious, praying, 14th century Europe; and mid 15th century saw spring-driven mechanism develop. The structure of this was greatly influenced by church architecture. Water clock is another clock. It was most important. Due to regular flood of Nile it was important for Egyptian's to get awareness of time and clepsydra water clock developed around 1400 BC. Pendulum clock is another clock. It was developed in the 17th century by Dutch and accuracy was increased after the this discovery. Sand clock was developed in 1500 BC and still is being used today in the form of an egg timer. It used the flow properties of the sand. Candle clock depend on the steady burn rate of wax to show the passing time. During windy days it shows problem. First radio alarm clock was developed by James F. Reynolds in the 1940. First mechanical clocks use the system of gears for escapement. The most recent innovation regarding alarm clock was happened in early 2006.

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