Watch complications

In watchmaking, a complication refers to a complex mechanism that adds an additional function, other than indicating the hour, minute and second on a watch. In this article, discover the 5 families of watch complications.

1) Watches with sound signal

Alarm

The alarm is a complication that allows the watch to emit an audible signal at a preset time. It is particularly useful for appointment reminders or as an alarm clock. On mechanical watches, the alarm is usually set using an additional crown. The sound can be produced by a miniature speaker or a hammer striking the case. Some models, such as theOmega Seamaster Memomatic, allow adjustment to the minute and offer automatic winding of the alarm function.

Minute repeater

The minute repeater is a sophisticated complication that indicates the time on demand by means of an acoustic signal. It generally uses two small hammers producing different tones for the hours, quarter hours, and minutes. For example, at 6:55, the watch will strike six low-pitched strokes for the hours, three high-pitched-low sequences for the quarter hours, and ten high-pitched strokes for the minutes. This complication is particularly appreciated for its technical complexity and its practical usefulness in the dark.

Big and small ringtones

Both of these chimes are considered to be among the most complex complications in watchmaking, requiring considerable technical expertise to manufacture and adjust. The latter automatically chimes the hours and quarter hours, as a church bell would, without any intervention from the wearer. As for the petite sonnerie, it is similar to the grande sonnerie, but does not repeat the hours every quarter.

These two complications are often combined with a minute repeater, allowing the time to be sounded on demand. The Patek Philippe Grande Sonnerie, for example, integrates these three sound functions into a wristwatch.

By the way

This complication refers to the ability of a watch to automatically chime at regular intervals, usually the hours and quarter hours, without intervention from the wearer. This is a typical feature of both grande and petite sonneries.

2) Astronomical watches

Moon Phases

The moon phase complication is a watchmaking device that allows you to track lunar cycles directly on the dial of a watch. It generally uses a rotating toothed disc (from 59 to 135 teeth, depending on the desired precision) that advances one notch every 24 hours and represents the moon and its different phases over a 29.5-day cycle. This complication is appreciated for its aesthetic beauty but also its poetic connection with nature. 

Calendars

Calendar complications are among the most common and useful in luxury watchmaking. There are several types:

• Simple calendar: which displays the date of the month.
• Full calendar: which indicates the day, the date and often the month.
• Perpetual calendar: Which takes into account leap years and automatically adjusts for months of different lengths.

Equation of time

This complication displays the difference between mean solar time (civil time) and true solar time. Indeed, 

This complication measures the deviation between the actual position of the sun and a theoretical average position, which can vary from -16 minutes to +14 minutes over the course of the year. There are two types of display:

• A hand indicating the difference in minutes to be added or subtracted from civil time.
• The walking equation, which uses a second minute hand to directly indicate true solar time.

Astronomical indications

Besides moon phases and the equation of time, other astronomical complications exist:

• Sidereal hours : Display of time based on the rotation of the Earth relative to the fixed stars.
• Celestial map : Representation of the night sky visible from a specific location.
• Seasons and solstices : Indication of seasonal changes and solstices.

3) Chronographic watches

Chronograph

The chronograph is an instrument for measuring time between two events, integrated into a watch. Its operation is based on three main phases:

1. Starting position
2. Timing
3. Displaying the measured time

The classic chronograph generally uses two pushers:

• The first push button to start and stop timing
• The second push button for reset

The mechanism involves several components, including a column wheel, a control lever, and a clutch system to connect and disconnect the chronograph from the main movement of the watch.

Split-second chronograph

The split-seconds chronograph, also called a "split-seconds chronograph", is a more sophisticated complication of the classic chronograph, allowing the measurement of two simultaneous events. It has two superimposed chronograph hands:

• A main chronograph hand
• A split-second needle

Here's how they work:

1. Both needles start together
2. The split-seconds hand can be stopped independently to measure an intermediate time
3. The split-second hand can then "catch up" with the moving main hand.

Flyback chronograph

The flyback chronograph, or "flyback", allows the chronograph to be reset and restarted with a single press, without having to stop it first. This function is particularly useful for measuring successive time intervals quickly. This complication is particularly popular in aviation and motor sports, saving time when making consecutive measurements. Examples of flyback watches include the Breguet Type XX, the Zenith Pilot Flyback, and the Tag Heuer Autavia Chronometer Flyback.

Lightning chronograph

The foudroyante chronograph is a complication that allows fractions of a second to be measured with great visual precision. A hand that makes a complete revolution in one second

• Generally graduated from 1 to 6 (for movements in 1/6th of a second) or from 1 to 8 (for 4 Hz calibers)
• Often displayed in a separate meter for better readability

4) Watches with complications born from everyday life (useful)

These complications greatly enrich the functionality of the watches, making them particularly useful for international travelers and professionals working with global teams.

Multi-time zones

The multi-time zone complication allows the time in multiple geographic areas to be displayed simultaneously. The most common type is the GMT (Greenwich Mean Time) or dual time zone watch. It displays the local time with the central hands, with an additional hand to indicate the time in the second zone, often on a 24-hour scale. This complication is very useful for travelers and those who communicate with people in different time zones.

World time

More complex than the GMT, the world time watch simultaneously displays the time in all 24 major time zones, with a rotating disc with 24 cities representing each time zone, and another 24-hour disc with day/night indication. The local time is in the center of the dial

Power reserve indicator

This complication displays the remaining battery life of a mechanical watch before it stops. It usually takes the form of a circular or linear segment and is graduated either in hours, days, or in full/empty balance (like the percentage of a phone battery would be).

Day/Night

The day/night indicator is often integrated into GMT or world time watches. This complication allows you to differentiate between day and night hours using a color code (e.g. blue for night, white for day).

5) Watches with (technical) complications of realization

Unlike the other 4 families of complications, these do not add additional functions to the watch, i.e. the display of hours, minutes and seconds, as indicated by the definition of a complication. They are named as such because they represent the pinnacle of watchmaking engineering, combining precision, mechanical complexity and watchmaking tradition.

Whirlwind

The tourbillon, invented by Abraham-Louis Breguet in 1801, is a device designed to improve the precision of mechanical watches by counterbalancing the effects of Earth's gravity. Over the years, this mechanism has evolved into a flying tourbillon: held by a single pivot point, multi-axis tourbillons: with nested cages rotating at different speeds, or orbital tourbillons: rotating on itself and around the dial.

Carousel

The carousel, invented by Bahne Bonniksen in 1892, is an alternative to the tourbillon with a different construction: it has more components and is slower.

Chain rocket

The fusee-chain is an ancient mechanism designed to maintain a constant force in the watch movement. A chain connects the barrel (power source) to a conical fusee, which compensates for the loss of torque of the barrel spring as it unwinds.

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