Annual calendar
Encyclopedia
Annual calendar is the feature that refers to a mechanical watch
Mechanical watch
A mechanical watch is a watch that uses a mechanical mechanism to measure the passage of time, as opposed to modern quartz watches which function electronically. It is driven by a spring which must be wound periodically...

. It automatically adjusts months with 30 or 31 days and needs to be manually corrected when February turns into March. Thus it needs to be corrected once a year, which is why the calendar is called annual.

Functioning

A timepiece with an annual calendar displays the day, date, month and 24 hours which are automatically corrected every month. An annual calendar is less complicated than a perpetual one and thus less expensive. It is an intermediate between an ordinary calendar and a perpetual calendar
Perpetual calendar
A perpetual calendar is a calendar which is good for a span of many years, such as the Runic calendar.- General information :...

. The former needs to be corrected every month and the latter does not require adjustment till 2100 when a leap year will be ignored.

Brief history

The first annual calendar indicator introduced into a wristwatch was patented in 1996 by Patek Philippe. It was a revolutionary step in the world of watchmaking. Today, along with the moon phase and power reserve indicators, it is one of the most important and useful features of any timepiece.

Since 1996 the mechanism of an annual calendar was continuously improved and now it is used in watch
Watch
A watch is a small timepiece, typically worn either on the wrist or attached on a chain and carried in a pocket, with wristwatches being the most common type of watch used today. They evolved in the 17th century from spring powered clocks, which appeared in the 15th century. The first watches were...

 manufacture by several watchmaking companies. The annual calendar is not a common feature. It can be found in: Breitling
Breitling
Breitling is a luxury brand of Swiss watches produced by Breitling SA, a private company headquartered in Grenchen, Canton of Solothurn . The company exclusively offered Certified Chronometers in all models since 2000...

 (Navitimer Olympus), Bvlgari (Bvlgari Annual Calendar), Ulysse Nardin
Ulysse Nardin
Ulysse Nardin is a watch manufacturer founded in 1846 in Le Locle, Switzerland. Historically Ulysse Nardin was best known for being a manufacturer of marine chronometers, but today Ulysse Nardin produces complicated mechanical watches.-History:...

 (Marine Chronograph), Patek Philippe (Ref. 5035, 5135, 5146, 5147, 5396 and 5960).

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
x
OK