Many times the expression has been heard, “Tell me what the exact time is?” Why is the ‘exact time’ so critical? When is it important to get minimum fraction of the second, right? Precession has made human civilization crucial to time bound activities on earth. Such critical activities are rocket launches in space, athletes running for races, doctors performing life saving surgeries and operations, time bound GSP, decision of defence forces during war time etc. There was a time when radio controlled clocks were used only by security installations. The need of precise timing was important for national time zones. In developed countries, these devices have now reached the consumer market. Unlike the regular time keeping devices, radio controlled clocks are different. They are dependent on the time signal of radio stations. Most people set their personal wrist watches, wall clocks, desk clocks, by these radio controlled clocks. The broadcast frequency is organized by a standard frequency. This means the exact geographic location of each antenna is important to catch the radio signal time propagation. Each second interval is estimated, the signal is well modulated to identify current time. Different Radio Controlled Clocks have different hub or destination from which they can receive radio lengths. Today, even the common man is able to receive the radio wavelengths in ordinary watches.

The first radio controlled clock concept was initiated by Sir Howard Grubb, an engineer and an optical instrument maker. Before he attempted it in 1901, the first wireless signal passed through the Atlantic Ocean. Even before this miracle happened, another genius named Marconi used a spark-gap transmitter and an antenna to make a radio controlled device. In 1899 he managed to send signals between England and France. These operative devices receive wireless time codes and synchronize with the wavelengths within seconds. They are like atomic clocks. But unlike the atomic ones they have radio transmitters. The matching wavelengths are responsible for clocking time. They are now available to consumers with other products like car radios, cell phones, pagers and also television. They are also found in wall clocks, desk pieces, travel alarms and wrist watches. They work with precession and do not need to be adjusted. They are ideal for day light saving (DLS) geographical areas when time has to spring ahead and later fall back when DLS is over. The huge difference of one hour is self adjusted automatically.