But what even is time? IWC’s watchmakers surely asked such fundamental questions when they crafted the Portugieser Eternal Calendar, with its perpetual calendar that will calculate and display leap years accurately until the year 3999. The IWC team could have gone even further, but there has not yet been an official decision from the calendar-setting authorities on whether the year 4000 will be a leap year.

However, the real head-spinner on this 44.4mm timepiece with a platinum case is the moon phase. A normal precision moon phase will be one day off in 122 years, but according to the Schaffhausen maison, the Eternal Calendar will correctly show the moon phase with only one day of error after a whopping 45 million years. To make this feat possible, the team made more than 22 trillion AI-assisted calculations to establish the size of wheels and teeth needed. This resulted in a reduction gear train with three intermediate wheels.

IWC is primarily known for flieger-style pilot watches and at last year’s Watches and Wonders, revisited the Gerald Genta-designed Ingenieur sports watch; so the focus on the dressier Portugieser line, giving us such advanced calendar and moonphase innovations in one piece, is a huge shift – though not one the brand is making alone.

Over at Jaeger-LeCoultre, the spotlight was on the Duometre collection, which focuses on a patented mechanism invented in 2007, sporting double barrels and two gear trains. Rather than a single barrel and gear train splitting its power between both the main timekeeping functions and additional, elaborate complications, the Duometre allows the maison to add complications without compromising on the energy needed to maintain precise timekeeping.

Of this year’s new Duometre pieces, the Heliotourbillon Perpetual was the star of the show, as the double gear train powers a triple-axis tourbillon escapement visible through the left-side cut-out of the dial. The three tourbillon cages – one for each axis – are made of titanium, thus weighing 0.7 grams despite comprising 163 components, all helping to compensate for gravity’s adverse effect on precision. The watch also has a perpetual calendar with a patented way of indicating the leap year: the last number of the calendar year shown in red.

Hermès also surprised with a mesmerising triple-axis tourbillon this year, placed at the centre of the Arceau Duc Attelé. The complication hovers above the minute repeater at 6 o’clock whose hammers are wrought in the shape of horse heads, linking its 187-year-old equestrian past with its comparatively younger, mere decades-old foray into high horology. Fittingly, the Arceau Duc Attelé comes in a case of titanium – a 20th century material – or rose gold for a more classic feel.

Another double mechanism aimed at extra precision is found in Ulysse Nardin’s Freak S Nomad with its two oscillators coated in Diamonsil – a kind of diamond-coated silicon – and a minute indicator, all situated on a flying carousel rotating on its axis every hour. This highly technical solution, reminiscent of a spaceship as is the Ulysse Nardin way, is placed on the rotating, handmade guilloche baseplate of the movement, which makes a full circle in 12 hours. The combination of hi-tech solutions and materials, and the hand-operated guilloche – a technique for machine-aided engraving of decorative patterns that has been around since the 18th century – makes the Nomad a showcase of centuries of know-how.

Tourbillons, calendars and double solutions weren’t the only complications explored this year. Tag Heuer gave us the Monaco Split-Seconds, a rattrapante (split-seconds) chronograph that allows the wearer to time two events at once. The piece uses the brand’s most iconic case, the square Monaco, made immortal when Steve McQueen wore it in the film Le Mans, released in 1971.

The Split-Seconds has an openworked design with central arches holding the subdials, revealing some of the wheels and cogs – if you can look past the orange hands of the chronograph and equally colourful indexes. With this timepiece Tag Heuer combines an elevated horological game with its heritage of sports and racing timekeeping.

However, the most notable complications piece from Watches and Wonders this year may not be a wristwatch at all. Vacheron Constantin presented the horological equivalent of extra everything in The Berkley Grand Complication “pocket” watch, a timepiece made for W.R. Berkley, an American billionaire businessman and philanthropist. The piece has a whopping 63 complications, dethroning another Vacheron Constantin watch, the reference 57260, which has a “mere” 57.

Christian Selmoni, style and heritage director at Vacheron Constantin, said in a statement that while one might have thought the reference 57260 represented the “last word” in the field, “it is possible to take demands a step further by achieving what no one has ever managed before.”

On the piece’s horological menu is a perpetual Chinese calendar accurate until the year 2200, alongside a Lunar New Year date display, star charts, a grand sonnerie, retrograde small seconds and a three-axis tourbillon. Given its diameter of 98mm, thickness of 50.55mm and weight of 980 grams, Mr Berkley will probably need to wear a tailored waistcoat just to carry it around.