Calendar Watches

Calendar Watches: FAQs

What is a calendar watch?

Calendar watches are mechanical timepieces that display the date, day of the week and month on the watch face. The watch will monitor the different months, monitoring those that have 30 or 31 days, but does need adjusting by the wearer once a year.

The first variation of this complication, that required adjustment just once a year, was Patek Philippe‘s 1996 release of its reference 5035.

What is the difference between a calendar watch and a perpetual calendar watch?

A calendar watch requires manual adjustments, whereas a perpetual calendar involves a more complex, automatic mechanism that accounts for the date itself. Here’s a more detailed breakdown:

• Calendar: In order for the watch to display the correct date, the wearer must make manual monthly or annual adjustments for the shorter months of the year. The complication will usually show the correct date for longer months, i.e. those that have 31 days.
• Perpetual calendar: The perpetual complication automatically accounts for varying month lengths (including the number of days in February and leap years) and requires no manual adjustment until the year 2100.

Which complications can be combined with a calendar function?

• Chronograph: Allows you to measure time intervals independently of the main timekeeping function. 
• Moonphase: Shows the sunlit portion of the moon as seen from Earth, often for aesthetic purposes rather than practical ones.

Do all calendar watches automatically adjust at midnight?

No, not all calendar functions automatically adjust at midnight. While they do advance by one day at midnight, they must be manually adjusted for shorter months, i.e. February, April, June, September and November.