In the 1920s, the celebrated watchmaker Patek Philippe produced many watches with a cushion-shaped case. And, in 1925, it became the first in the world to produce a wristwatch with a perpetual calendar.

In March 2012, one of its novelties at Baselworld is a tribute to those exciting days in the form of an ultra-thin (2.53mm), perpetual calendar wristwatch with a 22 carat yellow gold oval case housing a 'Caliber 240 Q' mechanical self-winding movement.

The watch will faithfully maintain the correct day and month until 2100 when the idiosyncrasies of the Gregorian calendar decree it is NOT a leap year. From 2100 onwards, the watch need not be adjusted for another 100 years. Likewise with the phases of the moon: such is its accuracy that just one change needs to be made every 122 years.

Photos: Patek