Watch complications are features or functions in addition to timekeeping. Some common types of watch complications include:
- Chronograph: a stopwatch function to measure elapsed time
- Perpetual calendar: displays the date, day, month, and year and automatically adjusts for leap years
- Moon phase: displays the current phase of the moon
- Tourbillon: a mechanism to counteract the effect of gravity on a watch's accuracy
- Alarm: a reminder function that sounds an alarm at a preset time
- Power reserve indicator: shows the remaining power in a watch's mainspring
- GMT/dual time: displays two time zones simultaneously
- Split-seconds (Rattrapante) chronograph: a chronograph with two second hands that can be started, stopped, and reset independently
- Minute repeater: strikes a mechanism that chimes the hours and minutes on demand
- Annual calendar: displays the date, day, and month and requires manual adjustment once a year for non-leap years.
These are just a few examples of the many types of watch complications that exist.