Apart from the exact time, what people want to know most when they look at their watch is the current date. The date display ranks just behind the hour, minute, and second indications even though it is a comparatively recent development in the long history of horology. In fact, the first wristwatches with analogue dates were introduced in the early 20th century.
In developing the ATUM DATE collection, watchmakers at Moritz Grossmann have drawn inspiration from a classic display method and evolved it by making their jumping date remarkably easy to use.
The ATUM Date emphasises the date indication with a complete scale set around the outer dial. However, to integrate the jumping date mechanism on the dial side of the movement, it was necessary to redesign several elements. The additional setting crown at the 10 o’clock position reveals the complication at first sight and is the key to the simple and elegant solution developed by Moritz Grossmann.
Achieving such an elegant and streamlined timepiece requires skills, creativity and a heightened sense of design. The ATUM Date is nothing short of technical brilliance interpreted through beauty.
INGENUITY: THE DATE SETTING CROWN
The pusher beneath the crown of the Grossmann manual winder and the separate date setting crown on the opposite side at 10 o’clock are visible manifestations of this model.
The design objective of the Grossmann date was clarity of style paired with simple, problem-free operation. This convenience immediately comes to the fore when the date needs to be corrected (eg following a short month). The date can be changed in either direction at any time while the movement continues to run. The date crown is pulled out and turned in the desired direction until the marker lines up with the current date. When the crown is pushed home, a spring causes the date ring with the marker to precisely engage in the right position.
SIMPLICITY: THE DATE DISPLAY
On the solid-silver dial, the minute scale was moved slightly inward to make space for the date scale. Its crisp Arabic date numerals are blue and thus contrast well against the time scale. Instead of a conventional date hand from the centre, the date marker moves along a peripheral ring and therefore does not compete with the minute hand. Its bracket shape clearly frames the current date. This type of indication, with a complete scale from 1 to 31, evokes an impressive consciousness of how steadily a month elapses.
The jumping date display of the calibre 100.3 relies on a complex system composed of a date ratchet wheel with a switching finger and switching finger spring as well as a release lever, a switching star and a date ring with the marker.
BEAUTY: THE HANDS
A typical hallmark of the ATUM collection is the lancet-shaped hands. They are manually crafted and finished for optimal results. The seconds, minute, and hour hands are annealed to a brown hue for the rose gold cases. For the white gold version, all hands are made of polished stainless steel.
For this model it was necessary to develop a new date marker as a substitute for a sweep hand. The new date bracket sits on the outside of the date ring suspended beneath the dial as it advances in a clockwise direction, day by day, along the scale of 1 to 31 days in the clockwise direction, completing a full revolution every 31 days.
The date marker is also completely handmade and annealed to a brown-violet hue as a contrast to the blue date numerals. With its bracket shape, it clearly frames the current date numeral, assuring fast legibility and crisp delineation.
Case: 750/000 white gold
Hands: Hand-crafted, annealed to a brown hue
Movement: Manufacture calibre 100.3, manually wound, adjusted in five positions
No. of parts: 259
No. of jewels: 26 jewels, 3 of which in screwed gold chatons
Escapement: Lever escapement
Oscillator: Shock-absorbed Grossmann balance with 4 inertia and 2 poising screws, Nivarox 1 balance spring with No. 80 Breguet terminal curve, Gerstenberger geometry
Balance: Diameter 14.2 mm, frequency 18,000 semi-oscillations per hour
Power reserve: 42 hours when fully wound
Functions: Hours and minutes, subsidiary seconds with stop seconds, Grossmann winder with pusher
Special features: Grossmann balance; handsetting override and start of movement with lateral pusher; precisely jumping date display with a peripheral marker; bidirectional date adjustment with a separate crown at 10 o’clock; space-saving modified Glashütte stopwork with backlash; adjustment with Grossmann micrometer screw on cantilevered balance cock; pillar movement with 2/3 plate and pillars made of untreated German silver; balance cock and escapewheel cock hand-engraved; broad horizontal Glashütte ribbing; 3-band snailing on the ratchet wheel; raised gold chatons with pan-head screws; separately removable clutch winding mechanism; stop seconds for handsetting
Operating elements: Crown in 750/000 gold to wind the watch and set the time, pusher in 750/000 gold to start the movement
Case dimensions: Diameter: 41.0 mm, height: 11.85 mm
Movement dimensions: Diameter: 36.4 mm, height: 5.0 mm
Case: Three-part, precious metal
Dial: Solid silver, indices in solid white gold
Hands: Steel, hand-crafted, annealed to a brown hue
Crystal/display back: Sapphire crystal, antireflective coating on one side
Strap: Hand-stitched alligator strap with pin buckle in white gold