We’ve spoken before about the perpetual calendar complication and just how great it is. However, today we are just going to focus on the purest and simplest form of a complication: the date. Ultimately, the date complication is the most elemental form of a calendar found in a watch. It uses the watches 24-hour cycle to update the calendar to display the correct date. Now, the date complication on a watch is often put to one side, as not to intrude on the overall aesthetics of the dial. There are elegant ways to display the date on a wristwatch but none more so than the Outsized Date. It is the focal point of the timepiece and not an optional extra or bit part function.
I’ve always liked the idea of owning a timepiece with a big date window, just like those seen on timepieces from the likes of A. Lange & Söhne and Glashütte Original, to name just two. Of course, there are many more watch manufacturers who’ve created a timepiece with oversized date displays, but just where did it come from? Its inspiration came from the Five-Minute Clock that has been located above the stage of the Semper Opera House in Dresden since 1841. Visible from even the back row, the five-minute clock displays the hours and minutes (in 5-minute intervals) via a digital indication with Roman numerals for the hours and Arabic numerals representing the minutes. I’ve had the pleasure of visiting the Semper Opera House in Dresden and it is quite a marvel to behold.
You could question why the outsized date aperture is so large, but it is something that we’ve become accustomed to seeing in timepieces from Glashütte. You could almost say it is a standard feature of their timepieces. Looking at a basic Lange 1, which is arguably the most well-known outsized date timepiece, we will try to explain just how it works. The outsized date consists of two separate display elements: the units disc and the tens cross. They revolve one above the other with a clearance of only 0.15 millimetres, which requires extreme dexterity during assembly.
As mentioned, the outsized date consists of both a disc wheel and cross disc. To correctly reproduce the date sequence, the disc and the cross must advance at irregular intervals. The ring-shaped units disc switches once a day, except at the transition from the 31st of a month to the 1st of the next month: then, it stands still for a day. The tens cross advances by one increment every 10 days. However, when the “3” is displayed, the cross advances after the 2nd day, because the “3” is needed only to display the 30 th and the 31st of a month. To enable this irregular switching sequence, a programmed wheel whose special toothing pattern assures that the date is advanced correctly controls each display element.
So while at first glance the outsized date function may indeed just look like a blown-up version of the simple date complication, it is in fact a lot more complex than one would have thought. This is something that in my opinion A. Lange & Soehne, arguably, display the best.