Radio-Controlled
Accurate time. All the time
CITIZEN developed Radio-Controlled technology to provide people with the accurate time all the time. On a daily basis, a Radio-Controlled watch receives a time signal from an atomic clock with a margin of error of one second every 100,000 years to automatically correct small time-keeping deviations and set the date. CITIZEN debuted the world's first multi-band Radio-Controlled watch in 1993. As a pioneer of the technology, we remain a leader in the field.
Always.
Spot on
“Three. Two. One. Happy New Year!” Your watch is guaranteed to be absolutely spot on as the old year makes way for the new. The atomic clocks from which Radio-Controlled watches receive their time signals are accurate to one second in every 100,000 years! That means your Radio-Controlled watch will always tell the correct time.
Never behind.
Never ahead
Having to adjust your watch is a hassle. Radio-Controlled
watches synchronise the time and date late at night when
there is less radio noise from mobile phone signals and you
are already fast asleep. Because your watch does this
automatically every day, you don't need to adjust it
yourself. Ever.
* Receiving a time signal in places where
there is a lot of radio noise or there are range issues
can be difficult. Reception can also be affected by local
topography, buildings and weather. Make sure to check your
reception environment.
About Radio Controlled
Explore the technologies that go into Radio-Controlled.
No need to adjust the time
Radio-Controlled technology receives a time signal transmitted by an atomic clock accurate to one second every 100,000 years and automatically adjusts the time and date. Although this has now become one of the many functions that we take for granted on our smartphones, it was actually pioneered by CITIZEN. It is an epoch-making technology that always displays the correct time and eliminates the need for even minor adjustments. By raising the reliability of the watch, Radio-Controlled achieved a technological quantum leap.
Receiving time signals
in four regions worldwide
CITIZEN Radio-Controlled watches can receive time signals from transmitters in four countries: the United States, Germany, China and Japan.
Notes: This map applies to world multi-band models only. The diagram shows approximate reception ranges. The map and concentric circles indicating the standard radio transmission area are for illustrative purposes only and do not guarantee the radio reception range. Radio reception range varies depending on the watch model. Reception can be affected by radio noise, local topography, buildings and weather. Time differences and city names may change depending on national/regional circumstances.
Shrinking the antenna for a smaller watch
It's impossible to create smaller, thinner watches with more functions without first miniaturising the size of the antenna and reducing power consumption. The chart below shows our built-in antennas over a 15-year period starting in 1993, the year we launched our first-ever Radio-Controlled watch. Thanks to our success in antenna minituarisation, in 2008 we were able to develop the Caliber H010, a Radio-Controlled movement that is smaller than a one cent piece. Although our Radio-Controlled movements have become significantly smaller, they are not yet perfect. In the future, CITIZEN will keep on making ever-smaller antennas and reducing power consumption as we strive to make Radio-Controlled technology even better.
The Radio-Controlled Story
Bold vision. Exciting innovations.
An eternal theme for the watch industry
Achieving truly accurate timekeeping is the watch industry's most longstanding theme. In 1989, CITIZEN embarked on the development of a watch that would use time signals transmitted by atomic clocks to tell accurate time. Since we had no background in this field, there was a veritable mountain of technological challenges to overcome. Lacking the proper equipment, the development team had to rig up a makeshift antenna next to a window in their lab and build their own measuring device in-house to gauge signal reception performance. The team developed an IC capable of receiving standard radio waves and worked hard to miniaturise the antenna.
The world's first multi-band Radio-Controlled watch
We had to overcome numerous technological challenges before releasing the world's first multi-band Radio-Controlled watch in 1993. The metal case and metal components of watches can interfere with signal reception sensitivity—hence our opting for a bold, counterintuitive look for this model. The antenna sits right in the middle of the dial, highlighting the unique functionality of a watch that receives time signals.
The world's first light-powered Radio-Controlled watch
In 1996, CITIZEN developed the world's first Radio-Controlled watch incorporating Eco-Drive light-powered technology. We placed the antenna on the 9 o'clock side of the case, a decision that led to both improved signal reception and a more appealing design. The addition of automatic time-signal reception and light-powered technology simultaneously eliminated the hassle of adjusting the time and of replacing the battery.
Creating a more discreet and elegant design
Radio-Controlled had now evolved to the stage where the design of the watch no longer needed to explicitly reflect the technology inside. Having produced one model with the antenna in a resin case on the side, we went on to develop a low-power Eco-Drive model with an antenna built into a ceramic case. Further significant improvements to the antenna and the reception circuit enabled us to produce the world's Radio-Controlled watch with an all-metal case in 2003—a breakthrough previously regarded as impossible.
World's first Radio-Controlled watch with disc-type city selection function
Disc-type city selection function was a state-of-the-art technology and a world first when CITIZEN unveiled it in 2009. Pull out the crown one notch and turn it to select any of the 26 cities on the rotating disc. The watch will instantly display the time and date for your chosen city. This enhanced functionality made it easy to find out the time anywhere in the world.
World's smallest and thinnest watch* featuring world time
Female customers wanted a smaller, thinner Radio-Controlled
watch that was better adapted to their wrist size. In
response, we developed a new movement equipped with a new
signal reception IC and a completely remodelled antenna
structure. At the same time as retaining multi-band
reception, light-powered Eco-Drive and World Time function,
we had created the world's smallest Radio-Controlled
watch.*
* For an analogue light-powered
Radio-Controlled watch. As of August 15, 2016, according
to Citizen Watch Co., Ltd. research.
A watch showing the phases of the moon
The romance of tracking the lunar cycle is one of the many exciting possibilities inherent in Radio-Controlled technology. In 2023, we released the world's first analogue light-powered watch to feature a moon phase display. Working off the calendar information that the watch receives, the movement uses a special formula to automatically calculate the moon phase for that day, which is then automatically displayed in the window at the 6 o'clock position.
NOW
The future is Radio-Controlled
The full potential of Radio-Controlled has yet to be realised and we keep looking for better ways to apply this ultra-accurate timekeeping technology. In the future, CITIZEN will keep pushing the boundaries of the technology, exploring new concepts and developing new possibilities.
Some featured models are no longer in production or are unavailable outside Japan.