Leaping Through Time with Perpetual Calendar Watches

Leap years are eccentric by nature. I was recently amused to discover that they also have all kinds of superstitions associated with them.

In Greece couples often avoid getting married in a leap year, believing it to be bad luck. In other parts of the world there is a tradition that in a leap year the woman should propose to the man. In Italy they say: "Anno bisesto tutte le donne senza sesto" which means "In a leap year, women are crazy."

The subject is of particular interest to someone like me who is always surrounded by watches. Yes, another thing that might experience a slight ‘glitch’ in a leap year is the date window of your watch – unless of course yours has a perpetual calendar complication.

Watches with this complication are a little rarer, since they’re a lot harder to make – in fact it’s one of the “Holy Grail” complications as far as watch enthusiasts are concerned.

The first watch with this function was made by Patek Philippe. In 1898 they created the 97975 caliber, which was actually built into a ladies’ pendant watch.  This revolutionary movement featured a moon-phase complication, the date, day of the week, and the month.

But it wasn’t until 1925 that Patek Philippe started putting a version of the 97975 movement into wristwatches. The first one was made for a wealthy American connoisseur, Thomas Emery, who owned it until 1951, when the watch company bought it back for their museum.

Since then quite a number of watches have been produced with this complication, but they tend to be on the high end of the market. The complexity of the mechanics needed to keep the date accurate for centuries is not something every watchmaker can pull off, especially if they’re making every part of it in-house.

A notable exception is the Jaeger-LeCoultre Master Ultra Thin Perpetual Calendar. The caliber 868 movement is quite an achievement for this watchmaker. Consisting of 336 pieces, including 46 jewels, the remarkable thing is that JLC watchmakers fit all of that into a height of only 4.72mm and 39mm in diameter.

The Moonphase display near the 12 o clock marker actually turns red between 10pm and 2am reminding you not to adjust the watch. The reason for this is that on many perpetual calendar watches adjusting the date can seriously damage the fine mechanism inside, unless done in the proper way at the proper time. Perhaps most remarkable of all is the JLC have made this highly complex watch so affordable – when it went on sale in 2013 it was priced at under $20,000.


Kurt Klaus from IWC has been designing Perpetual calendar watches since 1985. One of IWC’s finest models is the Portugieser Perpetual Calendar. What I find interesting about this design is that it is operated using just the crown – there are no pushers at all. The movement inside is the IWC caliber 51614, and the day, month, moonphase, and year are always completely in sync.

IWC claims that the depiction of the moon’s orbit on the miniature stage diverges by just 1 day in 577.5 years from the actual phase of the moon.

The Portugieser is available in silver-plated, ardoise, and this very attractive (and rare) blue dial which changes tone with changing light conditions.



  • http://www.watchcollectinglifestyle.com/home/experience-patek-philippe-celebrates-its-175th-anniversary-a-chronological-journey-of-its-history
  • http://www.theversatilegent.com/wp-content/uploads/2014/03/L1200205.jpg
  • https://www.hodinkee.com/articles/just-because-the-iwc-portuguese-perpetual-calendar-in-white-gold-with-a-blue-dial

Leave a comment

All comments are moderated before being published