Patek Philippe launches a new Calatrava with instantaneous day-date displays and an eight-day power reserve. The new manually wound31-505 8J PS IRM CI J caliber combines a classic construction with several technical innovations, including a Pulsomax ® escapement in Silinvar ® . The two series-coupled barrels guarantee perfectly accurate operation for a full eight days, with a ninth “reserve”day displayed in red on the indicator. The day-date displays jump instantaneously at midnight. The entire circumference of the white gold case band is adorned with Patek Philippe's emblematic hobnail pattern.