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.