Roger Dubuis Excalibur BiRetrograde Calendar Watch, 40mm Silver Dial, DBEX1179On a retrograde display, the hand moves along a semi circle scale and returns to zero at the end of each cycle. Mr. Roger Dubuis co patented his own retrograde mechanism in 1989, which became the basis for the Maisons first ever watch. This year, the Maison pays tribute to its co founders favourite biretrograde display, also named the ecliptic counters by the Maison as a reference to their elliptical shape and their particular function indicating