Shortly after starting his eponymous brand, Daniel Roth decided to tackle one of the most classic complications in horology, the perpetual calendar. To help him with this project, he approached none other than Philippe Dufour, who had only just begun his journey as an independent watchmaker. Not only was Dufour highly skilled in this sort of work, but he also happened to live just down the road from Roth's workshop. 

Together, they sought to develop the world’s first instantaneous perpetual calendar, where all the indications would flick into place, rather than gradually move into position. They used the Lemania 8810 as their ébauche, jointly developing a perpetual calendar module which would sit on top of it. According to Dufour, the process was rather laborious, even with his experience working on complicated movements. As he puts it, "I remember it being hard work. It took me about six or seven months to finish the movement.”

Roth first announced this project at Baselworld in 1991, where he presented a prototype featuring apertures for the day and date. However, as Roth and Dufour found out during the development process, too much energy was required for the indications to jump into place. As such, they replaced the digital display for the day and date with two sub-dials and corresponding sets of hands, in order to decrease the force needed to move all the gears. Evidence suggests that both versions were released at Baselworld in 1993, two years after the project was first announced. 

For this reference 2117, Roth reimagined the perpetual calendar dial layout, foregoing the traditional approach usually adopted by others. The sub-dial at 6 o'clock is used to indicate the date on the periphery, with the year on the inside, sinking lower down into the dial. As for the month and day of the week, these are displayed in two smaller sub-dials, with the former at 3 o'clock and the latter at 9 o'clock.

The watch has Roth's signature double-ellipse case, while the dial features a striking skeletonised design, which puts the watchmakers' innovative perpetual calendar module front and center. The time, date, and brand signature are displayed thanks to silver, brushed surfaces, which appear to float above the movement. The exposed mechanics display an impressive level of hand-finishing, with vertical brushing, mirror polish and bevelling visible on most of the surfaces. The baseplate features a traditional hand-engraving, in a floral pattern, which adds another level of ornate decoration. The lance-shaped hands are crafted from blue steel, another visual inspiration from the Abraham-Louis Breguet. 

As mentioned previously, the watch is powered by a reworked Lemania 8810 ébauche. On top of the automatic movement sits a perpetual calendar module, jointly developed by Roth and Dufour, and assembled within the brand's Vallée du Joux workshop. The movement is subtly finished, with chamfering on some of the angles, as well as polishing and decoration, in the form of Geneva striping. The rotor is made out of solid gold, and engraved by hand. All the operations on the movement required over 100 hours of work, according to a brochure from the period.  

If sold within the United Kingdom, this Daniel Roth Perpetual Calendar Skeleton will be subject to 20% VAT

Closer look

Condition

This Daniel Roth Perpetual Calendar Skeleton is in very good condition throughout. Light superficial marks are found throughout the case and lugs, most notably a small ding at the six o'clock position on the bezel. The case retains its correct original proportions and sharp lugs. Substantial oxidation is visible on the left side of the case, surrounding all of the perpetual pushers as well as the top left lug. This has be left untouched, though can be removed through polishing. The dial, movement and hands are free from any signs of imperfection. The hallmarks on reverse side of the lugs and engravings on the caseback are crisp and well defined.

Warranty

The watch comes with a two-year warranty from A Collected Man, alongside a lifetime guarantee of authenticity.