Yes and no. There are several calendar week displays on the market ...October 24 2006 at 4:12 AM
Marcus Hanke (Login mhanke)
Brand Forum Moderators
Response to Oh, and I believe Mühle . . .
... even the private label producer Epos has one, if I remember correctly. Other are/were from Kelek, Nivrel, Breitling (?) etc. Now Lange, too, has presented one. However, there is a huge difference with the new GO mechanism: All previous display used conventional pointers, so it is no problem to switch from 52 to 1. GO is the only manufacturer ever to make a big display with separate disks for the tens and single digits. And there it is indeed a huge challenge to switch from 52 to 1.
Please note that even in perpetual calendars with big dates, the disk for the single digits either rests where it is (when switching from a 31st to the 1st of a month), switches one (from 30 to 1), twice (in leap years: from 29th of February to 1st of March), or three times (February 28th to March 1) at most. Even the latter consumes a considerable amount of enery, and many watches have to distribute the complete switching process over about several hours so that the sudden energy consumption does not affect the watch's timekeeping.
In GO's calendar week, the single digit disk has to switch nine times in a row! Every normal watch movement would inevitably stop to operate, fully exhausted. The typically ingenious way of the GO developpers was to integrate another spring barrel, used exclusively to power these nine switching operations. The normal movement is building up enough energy to power the daily switch of the panorama date, but also to the weekly switch of the week numer. As is not surprising, it delivers a lot more energy than needed for that, and a part of it is used to build up the tension within that special spring barrel, so that there is enough energy saved to conclude the "big switch", without affecting the watch movement's own power reserve. This is really, really clever!