The Gyrotourbillon 1 was the first 21st century Grande Complication from Jaeger-LeCoultre and it literally revolutionised the watchmaking world. The spherical tourbillon is associated with two fascinating complications: - a running equation of time: a dedicated star-tipped equation hand, tied with the perpetual calendar and running alongside the watch’s minute hand, displays the true solar time which, depending on the day of the year, shows a difference of several minutes compared with standard civil time. - a perpetual calendar with four retrograde hands: one for the months, one for the leap years as well as two large ones which divide up the task of running along the graduated date scale. The left-hand one handles the first half of the month, and the right-hand one the second fortnight. Two barrels with a sapphire crystal base and lid ensure an 8-day power reserve, representing an exceptional degree of autonomy for such a complicated watch.