All The Things You Need To Know About Perpetual Calendar Watch

Perpetual calendar watch is one of the terms that we normally see associated with very expensive automatic/mechanical watches. But then again, what is it actually and what it does? I decided to do a bit of digging and in this article, I will share what I found about perpetual calendar with you.

So what is a perpetual calendar watch? It is a watch with perpetual calendar function, which means the watch will be able to display the correct dates at all time, taking into account the different number of days in a month and even leap years. In terms of calendar, perpetual calendar is the most accurate that you’ll need.

In this article, I’ll be sharing about what exactly is perpetual calendar, its uses and its difference with ordinary calendar. Then I’ll give my take about the perpetual calendar watch, how it could benefit you and whether you should get one or not.

Table of Contents:

1. Perpetual Calendar Watch – Showing The Correct Dates All The Time On Your Wrist
2. What Is Perpetual Calendar Watch Used For?
3. Why The Number Of Days Are Not The Same In Every Month?
4. Differences Between Annual Calendar And Perpetual Calendar
5. How Does Perpetual Calendar Watch Work?
6. How To Set A Perpetual Calendar Watch?
7. History Of The Perpetual Calendar Watch
8. The Three Most Important Things To Know About Perpetual Calendar Watch (Before You Buy One)
9. With Perpetual Calendar Watch, The Longer The Power Reserve, The Better
10. Is Perpetual Calendar Watch For You?

Perpetual Calendar Watch – Showing The Correct Dates All The Time On Your Wrist

Perpetual calendar watch has one additional function on top of the normal watch and that is to show the correct dates all year round on your wrist watch (but how important that is will depend entirely on individuals.)

We’re thought from when we’re kids that every month comprises different number of days, either 30 days or 31 days in a month, with February being an exception with 28 days. There’s also the problem of leap years, whereby during that year the month of February will have 29 days instead of the typical 28.

This poses the problem as most normal watches with analog display uses a simple mechanical function to change the date display once 24 hours passed. This default setting will just cycle the dates until 31 and then it will go to 1 – this kind of calendar is called simple calendar.

Thus, this irregularity in the number of days every month will give the hassle of having to change the date manually at least every 1/2 month (depending on what month you first set the watch).

But do note that this problem only exists with analog watches (automatic or quartz movements). For digital watches, most often than not the calendar is programmed inside the chip giving it the ability to display the correct date (much like our computer and phones).

What Is Perpetual Calendar Watch Used For?

Perpetual calendar watch is used to display the correct date every time which is why its called “perpetual” (though actually most of these watches do need to be adjusted after a certain time e.g 100 years, so it’s not really perpetual but correct up to a very long time).

If you’re wearing your watch every day and don’t want to be bothered with tinkering around it because you have more important stuffs going on, then perpetual calendar watch can be a good option. It will help to keep the date displayed on your watch correct while you go about with your busy lives.

Why The Number Of Days Are Not The Same In Every Month?

Throughout mankind’s history, our calendar have gone through many reforms and changes, along with advancement in astronomical knowledge as well as technology.

There are two main types of calendar, lunar calendar (depends on moon’s revolution around earth) and the solar calendar (depends on the earth’s revolution around the sun), with the latter the most formally used nowadays. Both calendars have the same problem: there is simply no easy rule regarding these calendars because the moon and earth does not revolve at an easy predetermined duration.

For the solar calendar, the current set of calendar that we use currently is called Gregorian calendar that after accounting for leap years, averages the year into 365.2425 days long – yes, it’s not exactly 365 days long hence the root cause of the problem at hand.

In a normal year, there are 365 days in a year divided into 12 months. To achieve this, the calendar divides the months into 30 & 31 days alternately though there are some exception here and there such as July and August that both have 31 days and February having 28 days. You can refer to the exact number of days on any calendar or on this page.

But there also exist a leap year whereby the number of days in a year is 366 days. In order to account for this, February is increased by 1 day to be 29 days. These leap years only occurs once every 4 years and is one of the adjustment methods in order to account for the natural revolution of the earth around the sun that is not exactly conforming to our standard days.

Although these rules are quite easy to comprehend, it’s not as easy to implement on a mechanical analog watch that works best on anything linear or uniformly moving. As watchmakers tried to implement the unique, it is the beginning of a perpetual calendar watch.

Differences Between Annual Calendar And Perpetual Calendar

There’s also the annual calendar watch, the sibling to the perpetual calendar. The difference between these two types of calendar is in leap year adjustment : this makes the two watch types very different and is something that you must be able to tell as perpetual calendar do command higher price than annual calendar.

With an annual calendar, the watch needs minimal intervention to show the correct date as it’s designed to take into account day differences (30 or 31 days) for different months. February is a bit of an issue with some annual calendar watches able to display correctly display 28 days in February.

Do take note that there are some watches that cannot do this so it’s best if you find out about it before buying.

What is the difference between annual calendar and perpetual calendar then? A perpetual calendar is a step up in which it can correctly display the dates whilst considering leap years. This makes the watch require little intervention while in your possession as you don’t have to change its date.

This poses a slight problem when shopping for watches. While most watch dealers are good, some of them can be quite new in watches and can be misleading in explaining the features of their watches.

Thus, I recommend doing some due diligence on the particular watch model that you want to buy to be sure that it has the correct annual or perpetual mechanism that you’d like. A quick internet search would do well and I’ve found that internet forums can be very helpful too e.g watchuseek.com (treasure trove for helpful stuffs about watches), facebook groups (for lots of pictures) or even quora (for straight forward answers).

How Does Perpetual Calendar Watch Work?

So how does a perpetual calendar watch work? Perpetual calendar watch works through the use of multiple additional components in the form of gears and levers that act as mechanical memory to display the correct date – even considering different days in a month and leap years.

So in short, while a normal analog watch calendar has a simple disc with 31 days, a perpetual calendar watch will has a more complicated discs storing 4 years worth of day information!

Certainly this device is one of the hardest to do in mechanical/automatic watchmaking as it not only has the mechanical difficulty to map out the components, one also need profound knowledge of how perpetual calendar works and lastly, exquisite craftsmanship to manufacture the tiny components to exact dimensions and fit it in to work.

Fortunately things are much easier with advancement in technology. Nowadays digital watches can be easily configured to follow perpetual calendar and accommodate the leap years in their date display. The chip inside the watch is so advanced now that this can be easily done from the factory.

Just keep in mind that some cheaper digital watches might not have perpetual calendars built inside it. One way to spot this is if the watch does not have the ability to store or show month & year information. These infos are crucial for it to follow perpetual calendar and if you can’t find it, most often than not your digital watch does not have this built in it.

How To Set A Perpetual Calendar Watch?

Setting a perpetual calendar watch differs depending on the movement and how the watchmaker designed it. The simplest one is of course the digital watch type whereas inputting the correct day, date, month and year is all you need to do and the watch will take care of itself. In addition, such digital display is intuitive for us as most appliances nowadays have digital display.

But for an automatic/mechanical watch or for quartz watch with analog display, setting a perpetual calendar varies widely from model to model due to the basic difference in how the movement was designed. For example, the IWC Portugieser Perpetual Calendar (a great automatic watch with 7 days power reserve) is one of the easier watch to set up as you only have to set the date, month and year correctly.

However, it also has a flaw in which you can’t reverse the date if you’ve accidentally set it up few days ahead of the current date – the only way to reverse it is by sending the watch to a watchmaker (an official IWC watchmaker would be most preferable in this case…). Check out how the watch can be set up in the video below:

Above: a video about the beautiful (and USD 40k expensive!) IWC Portugieser Perpetual Calendar

Other perpetual calendar watches can be quite hard set up. If the watch is not intuitively designed (the IWC Portugieser above is a good one at that with day, date, month and year easily seen and understood), you’ll either have to figure it out by yourselves or better yet, refer to the user manual accompanied by it.

For instance, the Seiko Chronograph Perpetual calendar watch (a quartz) dial is quite complicated as the calendar display has to share the real estate with the chronograph displays. Hence, Seiko included a button function that can be used to display the date, month and leap year by the seconds hand needle. The way to set it is by setting the dates into one of the 14-variations that a perpetual calendar has.

Obviously, this is not as easy as the IWC but I’d say this set up is great for those that want a chronograph watch with a perpetual calendar as secondary function. Have a look at the Seiko watch in this informative below:

Above: Mark from Longislandwatch shows how the quartz Seiko Chronograph Perpetual watch works and how to set it (Note: even if you don’t buy from his website, he does have a great youtube channel with lots of info. check it out!)

History Of The Perpetual Calendar Watch

Perpetual calendar watches have been around since the 1700s, although it was mainly in the form of big and pocket watches mainly used for astronomical purposes. English watchmaker Thomas Mudge, was credited with inventing the first perpetual calendar watch way back in the 1762 in the form of a pocket watch.

Over the years, perpetual calendar watch remained in pocket watch form due to its bulky movement making it hard to fit a typical wristwatch. It was not until 1925 when Patek Philippe created the first perpetual calendar wristwatch for Thomas Emery, an American connoisseur of their watches.

Since then, numerous watchmakers such as Breguet, Jaeger-LeCoultre and IWC, just to name a few, jumped into the bandwagon and created their own perpetual calendar movement. It was and still is considered one of the noblest complications in automatic/mechanical watches due to its complexity and craftsmanship involves in making one.

With the advent of quartz and digital watches, perpetual calendar has become much cheaper due to the reduction in its manufacturing costs and has made it possible for normal people to buy and own a perpetual calendar =)

(If you want to know more about the history of these great watch brands, head over to my previous post about watch brands here)

The Three Most Important Things To Know About Perpetual Calendar Watch (Before You Buy One)

1) Perpetual calendar watch is more expensive than ordinary watch, and this difference can be thousands of dollars in the case of mechanical movement versions

With more features, the price of a watch will increase and this is certainly the case with perpetual calendar watches. Analog watches with perpetual calendar (either mechanical or quartz movements) will command a higher price than their ordinary counterparts due to the increase in numbers of parts and craftsmanship.

And if the perpetual calendar watch that you fancy has a mechanical/automatic movement, then be ready to spend thousands of dollars as it’s one of the hardest thing to do in mechanical watchmaking. One the plus side though, you’ll own one of the coolest watch around =)

2) Perpetual calendar watch needs to be always running for it to work

The second thing to understand is perpetual calendar watch is only perpetual if the watch is still running. This is logical because if the watch stops, the internal movement will stop counting the days and it won’t be perpetual anymore and you have to reset it again (which is quite cumbersome to do).

Mechanical/automatic watches require more attention as it has short power reserves, typically 40 to 50 hours. You’ll then need to ensure you’re always wearing them or putting it on a watch winder for it to always run.

Another thing that you can do is to get an automatic movement with higher power reserves up to few days or even a week thereby reducing the possibility of the watch stopped.

For quartz watches, this issue is not very big as the battery inside it can last at least a year or so, thus you’re looking at the possibility of resetting the date annually at least when you’re changing the battery.

But if you truly want a fuss free perpetual calendar watch, then you can get a solar powered one. Solar watch is a quartz watch but has photovoltaic cells on it to convert light into electricity, thus charging the watch effortlessly. What this means is that this watch will not require any battery change for a long time. Due to this huge advantage, solar watch is about my favorite type of watch movement. You should consider getting one especially if you want watch with battery draining complications such as chronograph as battery depletion will be the last thing to worry about with solar watches =)

3) It’s more complicated to set

As I’ve elaborated above, setting a perpetual calendar watch is not as easy as we think it is. If you have trouble trying to set a normal day & date watch, then a perpetual calendar watch will be a nightmare for you. While it will not be a walk in the park, setting it is still very much possible if you follow the correct instruction. My advice is to not lose the watch’s instruction manual or you’ll be in for some trouble down the road lol!

With Perpetual Calendar Watch, The Longer The Power Reserve, The Better

For a mechanical watch, longer power reserve is definitely better. Usually, those owning a mechanical watch will like watches, so much so they will own few watches (I know because I’m one of these guys lol!). Thus, having longer power reserve is a great way to ensure that you can rotate between your watches without the need of having to set the time all too often.

And because of the difficulty in setting the perpetual calendar, having longer power reserve in a perpetual calendar watch is almost a must. The typical 40-50 hours of power reserve is too small as you’ll undoubtedly will have to set the calendar once or twice in any given month, which is just too much to do (unless you really like to do the date setting as a hobby…).

Fortunately, advancement in watchmaking technology, materials and movement design have made longer power reserves not a rarity anymore. We can now get longer power reserves in a mechanical watch, with some up to 65 days for a perpetual calendar watch (by Vacheron Constantin in its Traditionnelle Twin Beat Perpetual Calendar). Check out some of them in this great article here.

In addition, a power reserve indicator is a good accompanying complication that will make your life much easier. With it, you will be able to know when the power reserve will run out instead of just guessing so that you can take it out for a walk, do some manual hand winding or put it on a watch winder.

Is Perpetual Calendar Watch For You?

Should you get a perpetual calendar watch? Is it for you? Well, to be honest, this question can only be answered by yourself as you are the only one who knows whether you need it or not, and after going through its characteristics.

Without a doubt, perpetual calendars are very useful and will ensure you’re always aware of the actual dates at all time. But then again, automatic/mechanical movement version of the perpetual calendar watch is much more expensive and it might be difficult to justify such purchase, especially when the much superior and cheaper quartz/digital watches (which almost always have perpetual calendar programmed in it) are available at large.

Taking this into account, I just cannot recommend anyone, especially those with average income levels, to buy an automatic/mechanical perpetual calendar watch. True, it’s movement is very intricate and beautiful but in terms of practicality, it will definitely lose out to its better digital watch siblings.

Even then, there is nothing wrong if you want to buy it if you have the money. You can also get a used one at a heavily discounted price too. It is, in my personal opinion, a more aesthetically pleasing watch rather than the ubiquitous digital displays around us. If you got the money and would like to add a perpetual calendar watch into your collection, then go for it. Just be prepared to pay extra money and do the extra works involved with the watch =)

I hope this article will answer all your questions about perpetual calendar watches. Do let me know if you need further info about it by commenting below. Till next time.

Cheers!