Complications

А complication refers to any feature in a timepiece beyond the simple display of hours and minutes. A timepiece indicating only hours and minutes is otherwise known as a simple movement. Common complications in commercial watches are day/date displays, alarms, chronographs, and automatic winding mechanisms.

The more complications in a watch, the more difficult it is to design, create, assemble, and repair. A typical date-display chronograph may have up to 250 parts, while a particularly complex watch may have a thousand or more parts. Watches with several complications are referred to as grandes complications.

The initial ultra-complicated watches appeared due to watchmakers' ambitious attempts to unite a great number of functions in a case of a single timepiece. The mechanical clocks with a wide range of functions, including astronomical indications, suggested ideas to the developers of the first pocket watches. As a result, as early as in the 16th century, the horology world witnessed the appearance of numerous complicated and even ultra-complicated watches.

Ultra-complicated watches are produced in strictly limited numbers, with some built as unique instruments.

Grand complications
A grand complication is a watch with several complications, the most complex achievements of haute horlogerie, or fine watchmaking. Although there is no 'official' definition, one common definition is a watch that contains at least three complications, with at least one coming from each of the groups listed below:

Timing complications	Astronomical complications	Striking complications
Simple chronograph	Simple calendar	Alarm
Counter chronograph	Annual calendar	Quarter repeater
Split-second flyback chronograph	Perpetual calendar	Half-quarter repeater
Independent second-hand chronograph	Equation of time	Five-minute repeater
Jumping second-hand chronograph	Moon phases	Minute repeater