The complete calendar watch is like the Swiss Army knife of timepieces – it doesn’t just arrive with the classic hours, minutes and seconds. It cleverly displays the date, day, month and sometimes moonphase, and ingeniously recognises the months varying lengths and automatically adjusts the date accordingly.
There are two well-known complete calendar watches: the annual calendar and the perpetual calendar. The latter is the more advanced of the two and as such, the annual calendar watch sometimes gets a little less attention that its fancier and more expensive counterpart. So what exactly is the difference?
What’s the Difference Between Annual Calendar and Perpetual Calendar Watches?
As we mentioned in the introduction, an annual calendar watch delivers the date, day and month. The complication cleverly monitors the varying lengths of months, keeping track of those with 30 or 31 days confidently. That is until February. During this 28-day or 29-day month, the annual calendar watch requires a helping hand and will need to be manually adjusted. It’s just once a year though, hence why the annual calendar is named as such.
On the other hand, you have the perpetual calendar watch which surpasses the capability of an annual calendar watch by accommodating 30 and 31-day months and taking into account the number of days in February including leap years. Perpetual calendar watches require no user intervention as long as the movement is kept running.
For many, the perpetual calendar watch is the epitome of horological engineering and as such, these clever little devices can run rather expensive on the market. Annual calendar watches, however, are the more affordable option and as long as you’re happy to make just one manual correction once per year, they are a fantastic alternative.
Who Invented the Annual Calendar Watch?
You’d think that since the perpetual calendar function is the more complicated out of the two, that the annual calendar watch would have been born first. However, the perpetual calendar complication arrived several years earlier in 1792, created by English watchmaker Thomas Mudge. 130 years later and Patek Phillipe equipped the world’s first wristwatch with perpetual calendar function in 1925.
It wasn’t until over 70 years after the launch of the perpetual calendar watch that the annual calendar complication made its debut. Once again, Patek Phillipe took the lead and introduced the annual calendar wristwatch in 1996. Their aim was to simplify the perpetual calendar complication and make it just as functionally impressive but a touch more affordable. Their reference 5035, the world’s first annual calendar watch, remains a highly collectible design to this day.
How do Annual Calendar Watches Work?
Every annual calendar watch works differently, but typically the calendar complication features a 24-hour driving wheel with two fingers. The first advances the date every day at midnight. The second monitors the months, keeping track of those with 30 days and others with 31. For the months with just 30 days (April, June, September and November), the date wheel skips the number 31 to display the correct date. It is only in February, when the month has 28 or 29 days, that the movement must be manually configurated.
The annual calendar watch is a testament to the ingenuity of the horology world. It’s a pragmatic solution to the complexity of tracking varying months lengths and gracefully marries accuracy with user convenience. As such, it has carved its niche amongst timepiece enthusiasts who want to fully appreciate a complete calendar display without the price point of the more expensive, albeit less hands-on (by one day) perpetual calendar watch.
Whether you’re a business professional who requires a reliable and refined timekeeping companion to keep you in check during your busy lifestyle or you’re simply a watch enthusiast passionate about horology and some of the more complex watch complications in the industry, the annual calendar watch really is a must-have design for every watch wearer.
Thankfully, there’s no shortage of annual calendar watches out there already. As masters of the complication, Patek Phillipe has a number of exquisite calendar designs in their portfolio, as do luxury names like A. Lange & Söhne, Longines, Omega, Zenith and Montblanc. If your collection is missing one of the same, we highly recommend heading out into the world of watches and finding one for your wrist.