Moritz Grossmann expands its ATUM line with a new model with date indication and we have to say that the German brand could not have chosen a better display for this horological complication.
The complete date scale from 1 to 31 is displayed around the circumference of the dial of the new ATUM Date but instead of using a central hand, which could conflict with the hour and minute hands, the date is indicated via an unusually shaped bracket marker starting from the circumference.
This clever solution emphasises the elegance of the model without compromising in any way the functionality and the clean design typical of the line.
The calibre 100.3 of the ATUM Date is based on the calibre 100.1 of the ATUM line. Its characteristic elements, such as the pillar movement with 2/3 plate, wheel train, stopwork, removable winder module, escapement and oscillation system also feature the High-Artistic Finish.
The characteristic 2/3 plate in untreated German silver is decorated with wide horizontal ribbing with a hand-engraved signature. The Grossmann balance beating at 18,000 vibrations per hour is carried by the cantilevered, hand-engraved balance cock with the typical micrometer screw. Its design improves the adjustability of inertia and achieves high kinetic energy combined with minimised air resistance and the smallest possible mass. When fully wound, the movement has a power reserve of 42 hours.
The jumping date mechanism is a complex ensemble of parts that are integrated in the main plate on the dial side.
Both the winder and the hand setting mechanism are taken from the calibre 100.1. To prevent a simultaneous reverse adjustment of both systems or 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 jumping date 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.
Apart from the precisely jumping date, this type of date display has the additional advantage that the switching finger does not engage with the wheel train except for the few milliseconds during which the jump to the next date is taking place.
The date can be changed in either direction at any time while the movement continues to run. The separate setting crown at 10 o’clock allows the date to be easily corrected, for instance at the end of a month. Normally, this setting crown is not engaged, so inadvertent adjustments are prevented. The crown must be pulled out to set the date. During the process, the movement continues to run and the date can be set by turning the crown in either direction.
On the solid-silver dial, the minute scale is shifted inward to provide space for the complete date scale while the blue date numerals nicely contrast against the applied hour markers. Lavishly finished by hand, the bracket-shaped date marker is annealed to a brown-violet hue to contrast against the blue date numerals.
The typical lancet-style hands are annealed to a brown hue for a nice match with the rose gold case or made of polished stainless steel for the white gold model.
Like all other models of the line, the ATUM Date features the distinctive Grossmann winder with pusher, a refined hand setting mechanism that eliminates the ingress of particles into the case while the hands are being set as well as the unintentional alteration of the hand positions while the crown is being pushed home again.
In fact, when the user pulls the winding crown out, the winder switches to the hand setting mode and simultaneously stops the movement. The crown immediately returns to its home position but can now be turned to precisely set the hands. Once ready, the movement can be restarted by pressing the push button at 4 o’clock so avoiding the possibility to alter the positions of the hands. At the same time, the mechanism switches back to the winding mode.