Perpetual calendar chronographs and Patek Philippe are un-dissociable since 1941 when the Geneva brand introduced the reference 1518, the world’s first serially-produced perpetual calendar chronograph followed by what is considered one of the greatest watches of the 20th century, the reference 2499.

The tradition of this complication continues with Patek Philippe, the layout of the chronograph and calendar functions have more or less remained the same since 1941 with day and month indications read via an aperture at 12 o’clock, date and moonphase at 6 o’clock and the constant seconds and minutes counter at respectively 9 and 3 o’clock.

The reference 5270 perpetual calendar chronograph was introduced in 2011 (the pink gold version was introduced in 2015) and it featured for the first time an inhouse Patek Philippe chronograph movement (for the 3970 and 5970 Patek Philippe used a heavily modified Lemania base). It also added a day/night and leap year indicator on either side of the moonphase/date indication.

The reference 5720 has gone through different evolutions since its launch:

First series: Hands and hour markers are blackened white gold, offering the highest degree of legibility amongst all three series. The dial features railway minute divisions combined with Arabic five minute divisions, and was produced from 2011-2013.

Second series: In production from 2013 to 2015, a tachymeter scale that follows the contour of the subsidiary seconds counter is now added.

Third series: The tachymeter scale now stops where it intersects the timekeeping seconds subsidiary dial.

This rare pink gold perpetual calendar chronograph is only the fourth known example to appear at auction. Preserved in like-new, unworn condition, it is complete with its original certificate and presentation box.