A calendar watch is a type of mechanical or digital watch that displays the current date and sometimes other calendar-related information. Calendar watches can have different types of calendars, including the day of the week, date, month, and sometimes the year.
The simplest calendar watches display only the date, while more complex ones can show the day of the week, month, and leap year. Some calendar watches also have additional features, such as a moon phase display, which shows the phases of the moon.
In mechanical watches, the calendar function is typically powered by a system of gears and levers that advance the date display by one day at midnight. Some mechanical calendar watches also have a quick-set feature that allows the wearer to easily adjust the date display without having to turn the hands of the watch through a full 24 hours.
In digital watches, the calendar function is typically powered by a quartz crystal that vibrates at a precise frequency. The watch's microprocessor then uses this vibration to accurately keep time and display the current date.
Overall, calendar watches are a popular choice for those who want a watch that is not only functional but also displays useful information at a glance. They are available in a range of styles and price points, from simple and affordable digital watches to high-end mechanical watches with multiple calendar complications.