Buying a watch is a complicated business. And that’s not a reference to the bewildering array of styles and price points on offer. Because in the world of timepieces, complication means something your watch offers beyond time-telling.

That stopwatch? Complication. The day and date window? Complication. That swirling, gravity-defying gyroscope that set you back the cost of a house deposit? Complication. All are tests of the watchmaker’s craft, challenging their ability to fit more under the hood without you ending up with something alarm clock-sized on your wrist.

Complications were necessary feats of mechanical ingenuity in the era before quartz, and then your phone, simplified the business of telling time. If you wanted to time something, track the date, or know what time it was in the dark, cogs were your only option. Which drove watchmakers on an arms race to create increasingly complicated movements.

Today, most complications are aesthetic rather than necessary. Take the chronograph – a stopwatch with an independent, sweeping seconds hand, stopped and started with two buttons that flank the crown. Originally designed to track celestial movements, it proved invaluable for everything from directing artillery fire to motorsports and aeronautics (it’s still one of the defining elements of driving and pilot’s watches).

“Today the functionality is pretty much redundant as everyone has a stopwatch on their phone,” says Twisted Time founder Alan Moore. “But I find it adds a great aesthetic.”

The hard fact is that no one needs a pocket watch that tells you the temperature, on which day Easter falls, and what time the sun is going to rise and set every day.

Yet collectors look green-eyed at pieces like the $6m Patek Philippe Calibre 89 – which packs 33 complications into its 1kg, solid gold case – since timepieces like it, though far from practical, are the mechanical equivalent of a supercar that might only ever be unleashed on dual carriageways. For some, a waste of effort. For others, the ultimate demonstration of human ingenuity.

Patek Philippe Calibre 89 WatchThe Patek Philippe Calibre 89 packs 33 complications into its solid gold case

Though these days no complication is, arguably, useful in the most rigid sense of the word – whether it’s your phone or laptop, something else will generally provide the information for far less expense than a Swiss watchmaker – some are handier than others when it comes to daily life, or flashing your horologist credentials.

Timing

As Moore says, your phone has a timer. But sometimes, like for the mid-century racing drivers whose demands for increasing accuracy drove brands such as Omega, TAG Heuer and Zenith to fashion chronographs accurate to the 10th of a second, your wrist is a more practical place to watch the seconds tick by – whether you’re keeping tabs on your steak, rest periods in the gym, or how long that interminable meeting’s been dragging.

Note: some watches are stamped ‘Chronometer certified’. This isn’t a synonym; rather, it marks out timepieces that have been assessed for accuracy by the independent Contrôle Officiel Suisse des Chronomètres testing lab.

What To Look For

Chronographs come in numerous flavours but look for legibility – a glance off the track should suffice at 100mph – and simplicity. The chronograph is a complication that is often over-complicated.

Unless you’re marshalling a classic car race you don’t need a rattrapante (multiple seconds hands for lap comparison) and only regular pilots require a tachymeter (a dial on the bezel for calculating speed). Even then, only if their instruments fail.

A simple chronograph is as wearable with your suit as your sports kit, but these extra elements can clutter the dial and make your watch less office-appropriate.

Key Piece

Astronauts wear mechanical watches as a fail-safe, the argument being that though computers can crash, even in space cogs should still spin. So it proved in 1970 aboard the fated Apollo 13 mission, when Jack Swigert’s Omega Speedmaster timed a fourteen-second manual engine burn that corrected the ship’s course back onto a successful re-entry path.

To mark 45 years since the flight, the brand’s launched a commemorative edition – the Omega Speedmaster Apollo 13 Silver Snoopy Award (RRP £4,630) – with ‘What could you do in 14 seconds?’ inscribed beneath the first fourteen second markers, and an image of Snoopy – NASA’s safety mascot – in the chronograph’s running seconds dial and engraved, wearing a space suit, on the case back.

It’s a nod to the heavens, even if you only use it boil perfect pasta.

Omega Speedmaster Apollo 13 Silver Snoopy Award

Omega Speedmaster Apollo 13 Silver Snoopy Award

Omega Speedmaster Apollo 13 Silver Snoopy Award

Astronomical

We’ve always tracked time by earth’s progressions round its own axis and the sun’s. Astronomical complications display this information on a spectrum of practicality, from a simple date window through weekdays and lunar phases to the beautiful but largely useless positions of planets and stars.

What To Look For

The date is the simplest and arguably most useful astronomical complication. Cheaper watches default to a 31-day month and demand manual (but not exactly arduous) adjustment. In horology’s upper echelons you’ll find watches like the Patek Philippe Grand Complication, equipped with a perpetual calendar that requires no correction and can even take leap years into account. Handy if you wake up from a coma in a post-apocalyptic world, but still want to know how long it is until your birthday.

Other astronomical complications are pure aesthetics. A planetarium displays the positions of planets in the solar system, which slowly revolve around the dial. Just don’t let your watch stop unless you’ve the astronomy degree required to reset it.

Van Cleef & Arpels Midnight Planetarium Watch

As with a chronograph, simplicity is often best: “A complication that makes life easier lies in the GMT function; a second time of display is by far the most useful,” says Adrian Maronneau, buying director at The Watch Gallery. Alternatively, let aesthetics alone guide your choice – you have to look at it all day, after all.

“Moonphases, which follow the moon in evolution, and worldtimers, in which you can read various different time zones on a single dial, make for the most handsome choices.”

Key Piece

Certina is better known for chunky sports watches, but the DS-8 (RRP £540), announced at Baselworld this year, is an exercise in restraint – and makes the moon phase, a complication usually reserved for expensive mechanical watches, affordable to collectors with shallower pockets.

Certina DS-8 Chrono Moon Phase Watch

Horological

Many complications are less about functionality and more a display of horological one-upmanship – both of the maker’s skill and the wearer’s spending power.

The majority are found only in mechanical watches, either because they display something about the movement – such as a power reserve, which indicates how long until your watch needs winding – or because they’re neither useful, nor tests of craftsmanship in a quartz timepiece, so not worth having.

Take the minute repeater, for example, which dings out the time when you can’t see your watch and can set you back over £100k. It’s also rendered redundant by your phone’s light.

What To Look For

The most famous – and sought-after – is the tourbillon. “If you’re the type of man to buy a car for its engine, then you should look at a tourbillon,” says Maronneau. “The function, though not necessary, is of great use when showcasing the best of what the watch world can offer.”

These whirling cages are ostensibly designed to counter the effect of gravity on the movement, correcting for the seconds that slip when a watch is held in one position for a long time. Although not technically a complication – it enhances timekeeping, rather than offering something in addition – it’s nevertheless extremely desirable for high-end collectors due to its complexity.

Key Piece

The presence of a tourbillon adds at least one zero to your watch’s price tag. You’ll generally struggle to find one for less than £30,000, yet at this year’s Baselworld TAG Heuer’s boss Jean-Claude Biver (the man who almost single-handedly saved the Swiss watch industry at the height of the quartz crisis) unveiled the brand’s new Carrera Chronograph Tourbillon, priced at an unbelievably competitive £10,000.

Not pocket change, of course, but a mighty saving nonetheless.

TAG Heuer Carrera Chronograph Tourbillon

A special mention should also go to Storm, the British brand known for its quirky – if not exactly subtle – designs. At the same show it announced the Tourbo-X, the brand’s first tourbillon movement, starting at an astounding £3,299.

Its numeral-heavy dial doesn’t quite match the Carrera’s more refined design, but it should have a positive pull on the prices of its high-end competition.

Storm Tourbo-X Watch

Final Word

Complications are, perhaps, unnecessary. But in a world where a watch itself is a luxury rather than functional object, it’s these kinds of extra details that can turn your timepiece into something extraordinary.

Are you a watch collector and connoisseur, or a man who simply relies on his smartphone? Which complications do you look out for, and which do you deem surplus to requirements?

Let us know in the comments section below.