Big-date watches
References in the Grail Atlas catalog carrying the big-date complication.
A big-date displays the date through two stacked discs, units and tens, read through a window that is significantly larger than a standard date aperture. A. Lange & Söhne popularized the modern wristwatch big-date in the 1994 Lange 1, where the outsized date window is dimensioned to match the Semper Opera House's five-minute clock in Dresden. The complication is part legibility upgrade, part dial-geometry signature.
What to look for
The A. Lange & Söhne Lange 1 (101.027, 191.039) and Datograph define the modern reference. Glashütte Original's Panorama Date uses a single-window construction without the dividing rail, different mechanism, similar visual effect, and a brand argument that runs at trade shows. IWC's Portugieser 7-Day Big Date carries the indication on an automatic platform. The choice is mechanism (twin-disc vs. single-disc) and dial dividing line (present on Lange, absent on Glashütte). Big-date is one of the few date complications worth paying a premium for if you actually read the date.
A date two to three times the usual area, made by splitting the number across a units disc and a separate tens element rather than printing it on one ring.
How the big date works: history, mechanism, parts required, and what makes it hard to build →
