Glashütte brand Moritz Grossman has launched Atum Date, its first wristwatch with a date display at Baselworld. What’s unique about the watch is its innovative method of displaying the jumping date indication - it uses a date scale with an unusually shaped bracket marker that jumps at midnight to move to the next date. 

The Atum Date is available in white or rose gold.

The 41-mm case of the Atum Date – available in rose or white gold - uses a solid-silver dial with a recessed date scale from 1 to 31 on its perimeter. The dates are printed in blue which provide a pop of color on an otherwise sober dial. Date is displayed, not from the center but from the periphery of the dial via the use of an unusually shaped bracket marker.

At mightnight, the marker jumps to the next date. The dial uses applied indices for the hour markers and lancet-style hands. In the rose gold version, the hands (and bracket marker) are annealed to a violet brown hue while the white gold version uses polished stainless steel hands. 

The Atum Date is powered by a new in-house manufacture movement, the Calibre 100.3. Based on Calibre 100.1 used in the time-only Atum line, it retains the characteristic elements of the family like the pillar movement with 2/3 plate, wheel train and removable winder module.

Inspired by pocket watch movements, the movement’s bridges and plates are made from German Silver and is beautifully finished in the Glashütte tradition with annealed violet brown screws and gold chatons. 

Caliber 100.3 is based on the time-only Atum movement.

The jumping date mechanism is not a module, but integrated in the mainplate on the dial side. The jumping date relies on a complex system composed of the date switching ratchet, release lever, switching star, and the date ring with the bracket-style marker. The date ratchet consists of the wheel itself, a ring-shaped switching finger spring, and the switching finger.

The switching finger can freely rotate on the wheel but is secured by the ring spring in a position that allows movements on both sides but always requires tensioning of the spring. The mechanism is powered by the hour wheel at a ratio of 2:1, so the ratchet wheel fully rotates anticlockwise once every 24 hours. The transmission ratio of the date marker mechanism is calibrated to 11.6°, so the increments of the date ring add up to a total of 31 days.

A wrist shot of the Atum Date.To set the date, pull out the crown at 10 and the date can be moved in either direction.

The movement continues to run while the date is being set. To prevent a simultaneous reverse adjustment of both systems, and damage to the date switcher, the separate date-setting mechanism is uncoupled with a stop lever as soon as the hand-setting crown is pulled and the stop seconds device stops the watch. 

The unusual date display system not only lends a mechanical ingenuity to the timepiece, but also ensures that the watch’s face is clean and uncluttered. There is a real balance to the dial that is pleasing to the eye. The watch is paired with a brown alligator leather strap and is priced at $31,292 for the white gold version and $32,322 for the rose gold version.