The World's Most Complicated Watch - A Metonic Calendar

One of the last hints before the full unveiling on Sept 17.

What will be the world's most complicated watch features a surprising and unique complication: the indication of the Metonic cycle

Named after Meton, a 5th-century BC Athenian astronomer, the period of the Metonic cycle is 19 years and is notable because it is an almost perfect multiple between a solar year and a lunar month.

19 years is almost exactly equal to 235 lunar months and totals 6,940 full days. The difference between the two periods of 19 years and 235 synodic months is only a few hours. The Metonic cycle can be also be used to predict eclipses and is used for the calculation of the date of Easter every year.

Considering a year to be 1⁄19 of this 6,940-day cycle gives a year length of 365 + 1⁄4 + 1⁄76 days which is slightly more than 12 lunar months. To keep a 12-month lunar year in pace with the solar year, an extra 13th month is added on seven occasions during the nineteen-year period.

The in-house watchmaking team at Vacheron Constantin have developed the Metonic cycle indication as an integral part of a new and special calendar,  one of three interrelated but entirely different calendar systems incorporated within this watch.

 The World's Most Complicated Watch - A Metonic Calendar
This is really pretty awesome
08/28/2015 - 19:25

I cannot imagine how one would use this, but it makes me reflect on the person who has commissioned this.  One of the things that is so great is that this really focuses on the purest (and purist) concepts of watchmaking.  There are major technological innovations and new and unique complications, but they are dedicated to the classic purpose of measuring the passae of time in new and novel ways with precision.  It is not some odd thing (like altitude) or some odd use of materials (like glass tubes) or some innovation in decoration (like turbines or louvres).  There is a place for all of this, but the way this is done is like a true tip of that hat to classicism and innovation in one piece.  Awesome.