In Style + Design

A Complete Guide To Understanding Watch Complications

In the world of “haute horology”, the language of watch complications is an important one to master.

If you’re a relative stranger to the world of “haute horology”, some watches can seem complicated to the point of being illegible. Learn the language of watch complications and all will become clear.

While it’s true that many of the features on this list have been obsolete for decades, they aren’t necessarily included in modern watches for the sake of more accurate timekeeping. Rather, they are made to celebrate the history of horology and the skill of the watchmaker, often with nods to related fields like astronomy and navigation.

Here’s a rundown on the most sought-after watch complications on the market, and why collectors still go crazy over them.

Minute repeater

Speake Marin Renaissance Photo: Wikimedia Commons

Before the advent of phosphorescent dials and hands, telling the time in the dark could be very tricky. Enter the repeater, an extraordinarily complex watch feature which “repeats” the time to you through a series of chimes. The minute repeater does so to the nearest minute, while the quarter repeater chimes to the nearest quarter-hour.

The more accurate the repeater, the harder it is to construct, raising its value and collectability.


While most watches will have a small aperture to display the current day, you can also find calendar complications in the annual and perpetual varieties.

An annual calendar displays the day, month and year, and only needs to be adjusted once annually to account for leap-years. A perpetual calendar, on the other hand, features a good deal more gears and cogs than its annual counterpart, and will accurately display the day, month and year until requiring adjustment in the year 2100.

Moon-phase calendar

Rolex Cellini Moonphase Photo: Facebook

Originally found only in large longcase clocks, this complication was eventually introduced to pocket watches, and has been a mainstay in personal timekeeping ever since. From the cherubic “man in the moon” incarnation to spherical models engraved with craters, there are hundreds of styles of lunar indicator to choose from.

While functionally useless since the invention of the internet, the moon-phase complication is a charming reminder that the art and science of timekeeping came from the movement of celestial bodies.


Astronomia Tourbillon Photo: Jacob and Co Official/Facebook

French for “whirlwind”, a tourbillon is a fascinating little gadget that is usually positioned so it can be easily observed by the wearer, though it displays no information whatsoever.

The tourbillon was invented in the late eighteenth century to offset the effect of gravity on the balance-wheels of pocket watches, which could affect the accuracy of their timekeeping. Although there’s some debate around the effectiveness of tourbillons, the high level of skill needed to make them – and the aesthetic appeal of their whirling components – keeps them in high esteem.


Omega Planet Ocean Omega Watches Photo: Facebook

In everyday terms, this would be called a stopwatch function. It’s usually operated by a bezel-mounted pusher button and is a popular inclusion in sportier wristwatches like the Omega Planet Ocean.

Chronographs also come in “split-second” varieties, allowing the wearer to track the duration of two events concurrently.

Astronomic display

This kind of complication has many variations, from subtle stellar indicators to miniature planetariums. Most of the time, the mechanisms behind these displays are so complex that only professionals are able to adjust their settings.

Patek Philippe’s Sky Moon Celestial actually replicates the rotation of the moon and stars as seen from Geneva, using separate rotating discs of sapphire to stunning effect, while Jacob & Co. have a particularly ostentatious offering in their Astronomia Tourbillon, which balances the watch face, tourbillon, miniature moon and Earth on four rotating arms against a backdrop of stars.

Time zone complications

Having more than one time-zone on your wrist can actually be quite useful if you do a lot of travelling, and there’s quite a range of methods watchmakers use to achieve this effect. The simplest is to pair an additional hour-hand with a bezel that bears 24-hour indices and can be rotated to match the desired time zone.

There are also dual-time watches which feature an inset secondary dial, world-time watches with multiple GMT time-zones marked around an adjustable bezel, and truly unique pieces like the Christopher Ward C900 Worldtimer, which sports a world-map and highlights your current selected time-zone.

Equation of time

A feature appealing almost exclusively to horology nerds, the equation of time displays the difference between “civilian time” and apparent solar time. The time we use on a daily basis is only an average, while the “true” local time in relation to the sun varies by up to fifteen minutes, give or take, each day.

Useful, perhaps, if you like to plan your sunset viewing to the minute.

Dead-beat seconds

Perhaps the most ironic complication of all, this refers a second-hand which pauses between counting seconds – a feature commonly seen in inexpensive quartz and automatic watches.

In most mechanical watches, the second-hand glides smoothly along. But adding a one-second tick to its movement while keeping the rest of the timepiece functioning well is a feat of considerable difficulty.

This might be the ultimate expression of haute horology’s penchant for complexity over utility.

Published 15 February, 2018