Calendar complication
What is an annual calendar watch?
A calendar that knows which months have 30 and 31 days, so it needs correcting only once a year, at the end of February.
How it works
An annual calendar sits between a simple date and a perpetual calendar. It skips the 31st at the end of April, June, September and November on its own, but it treats February as a 30-day month, so on March 1 you advance it by one or two days.
It usually shows the date, day and month, and many add a moon phase. Because the mechanism is simpler than a perpetual calendar's, it's cheaper to make and easier to service.
History
Patek Philippe patented the annual calendar wristwatch in 1996 with reference 5035. It has since become one of the most popular practical complications, made by Patek, Omega, Ulysse Nardin, Montblanc and others.
Before you buy
An annual calendar gives you most of a perpetual calendar's convenience for much less money, from around $5,000 for some Swiss models.
Questions
- How often does an annual calendar need adjusting?
- Once a year, on March 1, plus whenever the watch stops.