Choose your language
English
Choose your currency
€ - eur
English
Your cart is empty.
Geplaatst op 13-08-2026 door Marc Hut
A watch that sets itself to the correct time, automatically displays the correct date and even takes leap years into account: that, in a nutshell, is what a PCAT watch does. Citizen, in particular, has popularised this technology by combining radio-controlled time synchronisation with a perpetual calendar and, in many cases, Eco-Drive and world time.
But what exactly does PCAT mean? Is there really an atomic clock inside such a watch? Does PCAT work anywhere in the world? And what is the difference between PCAT, Radio Controlled and GPS?
In this article, we explain the technology step by step.
At WatchXL, you’ll find this technology in our Citizen watches, Atomic Time Keeping watches and Citizen Radio-Controlled watches, amongst others.
It actually comprises two technologies:
Perpetual Calendar
A perpetual calendar that automatically knows how many days there are in a month and takes leap years into account.
Atomic Timekeeping
Time synchronisation via a radio signal, the time for which is derived from a highly accurate atomic clock.
As a result, a PCAT watch can keep both the time and the calendar accurate largely independently.
This receiver attempts to receive an official time signal at specific intervals. This signal is transmitted by specialised transmitting stations, whose time is determined using atomic clocks.
When the signal is successfully received, the watch compares the received time with its own internal time.
Has a discrepancy arisen? If so, the watch automatically corrects itself.
Depending on the movement used,Citizen Radio Controlled watches can receive signals from various parts of the world, including Europe, the United States, China and Japan.
In Europe, the German DCF77 signal is one of those used.
Actual reception depends, amongst other things, on:
So, when reception is good, you don’t need to check regularly to see if the watch is running a few seconds fast or slow.
This is one of the most common misconceptions about atomic timekeeping.
A PCAT watch does not contain an atomic clock. The watch simply receives a time signal from a transmitter linked to an atomic clock.
You can compare it to a radio. The newsreader isn’t inside your radio; your radio simply receives the broadcast signal.
A PCAT watch works in a similar way. The quartz movement powers the watch itself, whilst the radio receiver regularly checks whether the displayed time still matches the official time signal.
A simple watch with a date function usually does not know how many days there are in each month. After a month with 30 days, it may therefore be necessary to manually adjust the date from 31 to 1.
A perpetual calendar goes much further.
The movement knows:
As a result, the calendar on various Citizen watches can remain accurate well into the future. The exact mechanism and duration vary depending on the calibre.
For the wearer, this means, above all, great convenience: as long as the watch is set correctly, you hardly ever need to check the date setting.
A PCAT watch is therefore radio-controlled, but not every watch sold as ‘Radio Controlled’ is automatically designated as a PCAT.
Furthermore, at Citizen, various model ranges and movements may have similar functions without the name ‘PCAT’ being prominently used.
You should therefore always check the functions and calibre of the specific watch.
PCAT relates to time synchronisation and calendar functions.
Eco-Drive relates to the watch’s power supply.
Citizen does, however, often combine both technologies.
An Eco-Drive watch converts light into electrical energy and stores that energy in a rechargeable energy cell. Both natural and artificial light can be used, although strong daylight generally results in faster charging.
As a result, there is normally no need for the traditional periodic battery replacement.
The combination is particularly practical:
For anyone looking primarily for a watch that requires very little maintenance, this is an attractive combination.
Its exceptional accuracy therefore does not stem from the wristwatch itself containing an atomic clock, but from the fact that it synchronises with highly accurate external time signals.
Without a radio signal, the watch simply continues to run on its own quartz movement.
Depending on the Citizen calibre, the specified accuracy without a signal may, for example, be around plus or minus 15 seconds per month.
That is still very accurate for everyday use.
As soon as the watch receives a radio signal again, any deviation can be automatically corrected.
That is a key difference between a radio-controlled watch and a GPS watch.
A PCAT watch receives a signal from ground-based transmitting stations. The watch must therefore be within the reception range of a suitable transmitter.
For various multi-band models, Citizen uses reception areas around transmitters in, amongst others:
In the Netherlands and Belgium, reception of the German time signal is generally possible, but successful reception can never be fully guaranteed.
Thick concrete walls, metal structures and electronic equipment can, for example, interfere with the signal.
Are you travelling outside the reception area? The watch will not stop.
It will simply continue to function as an accurate quartz watch. Only the automatic radio correction will be temporarily unavailable.
If automatic reception fails, there are a few things you can try:
With many Citizen Radio-Controlled watches, you can also check whether the last reception was successful.
The exact procedure varies by calibre. You should therefore always consult the manual supplied with the watch.
Please also read our detailed guide on what to do if a Citizen Radio-Controlled watch is not receiving a signal.
For this to work, the correct time zone and settings must be selected, and the watch must be receiving the necessary time information.
With some movements, you can also switch automatic summer and winter time on or off.
You should therefore always check that the watch is set correctly after the time change.
The operation varies depending on the watch model. For a more advanced Citizen watch, it is therefore advisable to keep the manual for the relevant calibre.
Many Citizen PCAT and Radio-Controlled watches offer multiple cities or time zones. You select the desired location and the watch then displays the corresponding local time.
However, a PCAT watch does not automatically know where you are.
It does not have GPS positioning. Depending on the model, the wearer must therefore select the correct time zone or city themselves.
For example, frequent travellers might want to consider the Citizen Promaster Sky watches. Within this collection, Citizen regularly combines radio-controlled time with world time, Eco-Drive and chronograph functions.
A PCAT watch receives radio signals from ground-based transmitting stations.
A GPS watch receives time information from satellites.
A GPS watch therefore has an advantage if you frequently travel to areas that lie well beyond the range of radio-controlled time signals.
For someone who mainly lives and travels in Europe, however, a good radio-controlled watch is particularly practical.
If you’re looking for global satellite technology, you might also want to consider the Citizen Satellite Wave GPS watches. This is a different technology to PCAT.
Once the watch is set correctly:
Furthermore, PCAT does not require a smartphone, mobile app, Bluetooth or an internet connection.
So you’re wearing a traditional analogue watch that functions remarkably independently from a technical point of view.
It is precisely this that makes this technology so appealing to many watch enthusiasts.
The main drawback is its reliance on radio reception.
Automatic synchronisation may fail inside a large concrete building or far outside the transmission range.
A second point to bear in mind is the operation.
For example, some advanced Citizen models may feature:
This makes the watch versatile, but the initial set-up can be more complicated than with a simple quartz watch.
Furthermore, a PCAT watch is usually a quartz watch. Those who particularly appreciate the mechanical engineering of an automatic movement may find a PCAT less appealing.
On the other hand, it offers exceptional practical ease of use.
Eco-Drive means that a traditional battery change is not usually required on a regular basis, but the watch does contain a rechargeable energy cell.
In addition, components such as:
standard watch components that are subject to wear and tear.
Do you swim regularly whilst wearing the watch? If so, it is advisable to have the water resistance checked periodically.
It is also important to ensure that an Eco-Drive watch receives sufficient light on a regular basis. If the watch is stored in complete darkness for a very long time, the power reserve may eventually diminish.
The system is ideal for:
If, on the other hand, you’re looking for the character of a mechanical timepiece, an automatic watch is probably a better fit.
Both technologies have their own appeal.
An automatic watch showcases classic mechanical watchmaking. PCAT, on the other hand, demonstrates just how far modern quartz technology can be developed.
The Citizen CB0270-87L Radio-Controlled PCAT is a relatively classic model.
The model combines features such as PCAT, Eco-Drive and world time with sapphire crystal. The steel case measures 43 millimetres and the watch is water-resistant to 100 metres.
The blue dial gives the watch a more understated look than many of the more distinctly technical Promaster models.
Anyone looking for a sportier and more technical watch might want to consider the Citizen CB5006-02L Promaster Sky.
This model combines radio-controlled time and a perpetual calendar with features including Eco-Drive, world time and sapphire crystal.
With a water resistance of 200 metres and a distinctly instrumental look, this is clearly a different choice from a classic PCAT model.
The Citizen AT8238-84M is an interesting option for anyone looking for a technical watch that is relatively lightweight.
This model uses the H800 movement and combines radio-controlled time synchronisation with Eco-Drive, a perpetual calendar and a chronograph.
Thanks to the Super Titanium case and strap, the weight remains modest despite the case diameter of approximately 43.5 millimetres.
The most important thing is which calibre is in the watch and which functions that specific movement supports.
Look out for, amongst other things:
For everyday use, a relatively understated model may be more comfortable.
Those who travel a lot or enjoy using sophisticated technology will, on the other hand, find a more feature-rich model – such as one from the Citizen Promaster Sky collection – particularly appealing.
Also pay close attention to the size. A 45- or 46-millimetre watch feels distinctly different on the wrist to a 42- or 43-millimetre model.
So don’t just look at the technical features, but also consider how and when you want to wear the watch.
A PCAT watch solves several practical problems at once.
The time can be automatically corrected, the calendar stays accurate on its own, and on many models, Eco-Drive means you don’t need to change the battery regularly.
Add to that features such as world time, sapphire crystal and a chronograph, and you get a watch that can be technically very advanced without becoming a smartwatch.
PCAT is therefore not just a marketing term. It’s technology that actually benefits you in your day-to-day life.
PCAT stands for Perpetual Calendar Atomic Timekeeping.
A Citizen PCAT watch combines radio-controlled time synchronisation with a perpetual calendar. The watch receives time data from a highly accurate atomic clock, but does not contain an atomic clock itself.
The calendar takes into account varying month lengths and leap years, whilst many models also offer Eco-Drive, world time and other practical functions.
The system does have its limitations, however. Radio reception is not available everywhere in the world, and more advanced models may require a bit of study before you can master all their functions.
However, if you live in Europe and are looking for an accurate, reliable and technically interesting watch that requires little maintenance, the Citizen Radio Controlled PCAT is a particularly practical choice.
View the collection:
Would you like to know more about the power source behind many Citizen PCAT models? Then read about how Citizen Eco-Drive works.
Wondering which technology suits your preferences best? Take a look at our comparison between an automatic watch and Citizen Eco-Drive.
Is your radio-controlled Citizen watch not keeping accurate time? Find out what you can do if a Citizen Radio Controlled watch isn’t keeping accurate time.
Would you like more background information on the brand and the key technologies? Then read everything you need to know about Citizen watches.
