A calendar function is one of the most useful complications in a watch. There are several different kinds of calendar watches, ranging from simple date watches to complex perpetual calendars that can keep track of the date even in leap years. Read on to learn about the different types of calendar watches and see beautiful examples from top luxury brands.
The Different Types of Calendar Watches
Simple Date Watches
Simple date watches are the most common type of calendar watch. These watches usually have a window — also called an aperture — for the date. Beneath the window is a 31-day disk that makes a full rotation every 31 days. If a month has fewer than 31 days, you’ll need to manually reset it at the beginning of the next month. Nearly all watch brands make simple date watches.
If you want to know the day of the week and the date with a glance, a day-date watch is for you. It will usually have two apertures, one for each. The first and still the most iconic day-date watch is the Rolex Day-Date.
Complete Calendar Watches
A complete calendar watch shows the date, month, year, and day of the week. Watch brands can use apertures, subdials, or date rings to show all of this information.
Annual Calendar Watches
An annual calendar watch is smarter than a simple date watch. It accounts for the different days in the months, except for February. It only needs to be corrected once a year.
Perpetual Calendar Watches
Perpetual calendar watches, also called quantième perpétuel, or QP for short, accurately tell the day, date, month, and year even in leap years. Many perpetual calendars also show the moon phase. Multiple subdials are the most common way to show all of the information in a perpetual calendar, but some brands also use apertures. Because of the leap-year indication, you can tell a watch is a perpetual calendar and not an annual calendar. There will usually be either a window with the number in the cycle or a subdial with the numbers 1-4 or 1, 2, 3, and L for leap year. The 4 or the L are usually red to indicate that the watch is a perpetual calendar.