Quickset date feature
A quickset feature allows the day, date, or other features to be advanced more rapidly than by rotating the hour hand through a 24 hour cycle repeatedly.
Also called "rapid calendar advance" or "fast date correction", quickset features move various day or date mechanisms forward and sometimes backward. This stands in contrast to the "usual" method of setting these features, where the minute hand has to be moved to set the day or date. Some non-quickset movements can be set by oscillating forward and backward in the hour before midnight, but other features cannot be set in this way. If a quickset feature is present, a simple rotation of the crown in the pulled position is sufficient.
Various quickset date features were implemented starting in the 1950's, but some manufacturers were slow to adopt these for fear of damage (see below). Rolex was notably late, not implementing a quickset date feature until the 1970's with their Rolex 3035 movement family.
Single and Double
Some watches have both day and date indicators. A watch with both may be called "single quickset" if only the date can be set quickly or "double quickset" if both the day and date can be set quickly.
Before true quickset mechanisms were widely available, many watches gained a "semi-quickset" function, allowing the date to be advanced by moving the hour hand back to 9:00 and forward to midnight repeatedly. Although not as rapid and user friendly as a true quickset, this method was a welcome alternative to the old method of turning the crown many times to advance the hour hand through 24 hour cycles repeatedly. This mechanism is found on the popular ETA 2472 and Chronomatic, for example.
It is possible to damage the date advance mechanism by operating the quickset feature while the main date setting feature is engaged. For this reason, most manufacturers recommend not setting the date between certain hours, usually in the range of 21:00 to 01:00 but often narrower than this.
Many modern date mechanisms are spring-loaded to avoid breaking, but even those should be handled carefully during this "dangerous" time.
There are a number of different quickset mechanisms and methods, both historically and currently.
Second Crown Position
Most movements with this feature perform quickset in the second crown position, with the third (outermost) position used to set the time. Examples of calibres with quickset include ETA 2893-2 and Ebel 137 as well as the well-known chronograph calibre Valjoux 7750. Today many calibres feature quickset date using the second crown position.
The crown is unscrewed (if necessary) and pulled one "stop" out. This is the "second position" and allows the date to be set. In most such movements, the date is advanced by turning the crown clockwise in the second position. Some of these set the day wheel using a counter-clockwise motion, though a few use this to move the date backwards and have another mechanism to adjust the day wheel or lack this feature entirely.
Historically, many movements used a variety of correctors or pushers to adjust calendar functions. These were typically flush or recessed buttons in the case that could be pushed using a tool, toothpick, or pen to advance the date, the day, the month, or other functions such as moon phase or year.
This is especially popular on movements with additional calendar complications such as moon phase or month. For example, although the Valjoux 7750 has a second-position double quickset, the derived Valjoux 7751 uses a separate pusher to set the day.
A few manufacturers implemented a quickset function using a press or pull of the main crown. Seiko, for example, used a crown press to advance the date wheel in some movements from the 1960's and 1970's, including the 6139 chronograph. Similarly, others used a crown pull to advance the date wheel, including Eterna from their Eterna-Matic series.
A few movements, notably the automatic Orient 46 series, use a separate crown pusher to adjust the calendar. In the case of Orient, the second crown only adjusts the day wheel, while the date quickset is performed in second position on the main crown. Some movements also used a crown on the rear of the case for this purpose.
A fairly unusual mechanism ties the quickset feature to the reverse hour hand movement. As implemented by Buren in the Calibre 82 and others, the crown only has two positions. Second position clockwise advances the hour hand and second position counter-clockwise moves the hour hand backward. But each hour passed backward also advances the date wheel, allowing rapid setting of the date. This mechanism was used by many Ronda and Bettlach movements.