ATUM Date All Blue


As part of their 10th anniversary, independent Glashütte watchmaker Moritz Grossmann are presenting their third unique piece, the ATUM Date All Blue.

As with all Moritz Grossmann watches, the ATUM Date All Blue combines clear design with first-rate technology. Issued as a one-off as a variant on the ATUM Date, the watch is a fine example of integrated date setting technology alongside beautiful craftsmanship. In addition to the accurate jumping date display, the date can be corrected forwards and backwards at any time, up to less than one second before and after midnight. A separate locking crown at “10 o’clock” allows the date to be set by turning in both directions, forwards and backwards, without having to stop the movement.

With the ATUM Date All Blue, the silver dial harmonises with the blue hands and a blue date window. Continuing the theme, the watch uses blued steel screws, a rare variation on the otherwise predominantly brown-violet annealed screws at Grossmann.

The visionary and inventor Moritz Grossmann loved to study how watchmaking varied from area to area, exploring Hamburg, Munich, La Chaux-de-Fonds, England, France, Denmark, and Sweden to acquire the world’s horological know-how. His determination to broaden his knowledge was particularly unusual for his time, as it was very difficult to journey across the continent, with walking or travelling on horseback being the only options.

Under the tagline “Schönstes deutsches Handwerk”, the Moritz Grossmann brand manufactures timepieces to the highest standard of craftsmanship. The ATUM Date all Blue is offered with the calibre 100.3 in the high-artistic finish as a blue single edition 1 of 1.

The calibre 100.3

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Tech Specs


Manufacture calibre 100.3, manually wound, adjusted in five positions

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


Hours and minutes, subsidiary seconds with stop seconds, date display, Grossmann manual winder with pusher

No. of parts


No. of jewels

26 jewels, 3 of which in screwed gold chatons


Lever escapement


Shock-absorbed Grossmann balance with 4 inertia and 2 poising screws, Nivarox 1 balance spring with No. 80 Breguet terminal curve, Gustav Gerstenberger geometry


Diameter 14.2 mm, frequency 18,000 semi-oscillations per hour

Power reserve

42 hours when fully wound

Case dimensions

Diameter: 41.0 mm, height: 11.85 mm

Movement dimensions

Diameter: 36.4 mm, height: 7.56 mm


Three-part, precious white gold


Solid silver, hour markers in white gold


Hand-crafted, steel or stainless steel

Crystal / display back

Sapphire crystal, antireflection-coated on one side


Hand-stitched alligator strap with pin buckle in precious metal

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ATUM Date All Blue

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