Beyond Telling Time: 4 Special Watch Functions That Matter

16612968010 843c2b2e9c b1 Special Watch Functions That Matter

A guide to the ingenious features known as “complications.”

In the era of voice-activated, Wi-Fi-enabled smartwatches, it’s no longer a necessity to check your pulse or navigate using a mechanical timepiece. It’s a luxury. Which is why watch enthusiasts love a good complication (a watch function beyond just telling time). Here’s our guide to the big four—all of which are no less ingenious today than when they were introduced decades ago.

The Complication: Chronograph

Of all the complications, the chronograph is probably the one you will use the most. Despite being relatively simple in concept (a watch that’s also a stopwatch), the self-winding chronograph didn’t come along until 1969—the same year quartz wristwatches hit the market. Using a clutch that couples the stopwatch to the main timekeeping mechanism, these models measure passing time using various scales. One of the most popular is the tachymeter scale, which lets you determine the average speed of a vehicle over a mile or a kilometer. Many vintage chronographs use the pulsometric scale, which was developed for doctors to measure heart rate. Sure, you can get that from a Fitbit, but the Patek Philippe Ref. 5170G ($81,100), shown above, looks a helluva lot better on your wrist, don’t you think?

The crew of Apollo 13 used their Omega chronographs to time a critical midcourse correction on their return to Earth when nearly all the module’s electrical power was lost following an oxygen-tank explosion.

The Complication: GMT

The dual-time-zone, or GMT, watch has been saving the world traveler from jet-lag confusion for decades. Here’s how it works: One hour hand shows you the time at home (called, oddly enough, the home-time hand), and another indicates a time that differs by a set number of hours, giving you the local time anywhere your travels take you. Or almost anywhere: To make this complication more complicated, there are a few locales that are offset from Greenwich Mean Time (now known as Universal Time Coordinated, or UTC, for scientific reasons) in half-hour or even quarter-hour increments—and there are some countries, like China, that ignore conventions and use a single time zone across the entire nation. At those destinations, your dual-time-zone watch will be less useful, but luckily, these watches, like the legendary Rolex GMT-Master II ($8,450), pictured above, still work great as single-zone timepieces.

The first Rolex GMT-Master can go for staggering prices—in 2013, one fetched $268,145 at a Christie’s auction.

The Complication: Power Reserve

The heart of every mechanical wristwatch is a wind-up mechanism that’s not much different from a children’s play toy—and once the mainspring that keeps it moving runs down, it’s game over. Hence the power-reserve complication, which tells you how many hours of running time you’ve got left. Since the advent of self-winding watches, this may not seem like a big deal, but historically, the introduction to automatic watches of the power-reserve indication by Jaeger-LeCoultre in 1948 was a game changer for people worried about missing an appointment—or worse. Before GPS existed, when an accurate clock was essential for navigation, marine chronometers were fitted with power-reserve indicators to avoid errors that could result in, say, a shipwreck. Today this complication is typically found on watches with very long-running movements and implemented in often ingenious designs—like the Tudor North Flag ($3,675), shown above, which has a bright-yellow disc that indicates the reserves remaining.

The current power-reserve world-record holder for hand-wound tourbillon watches is Hublot’s MP-05 LaFerrari, which can run for 1,200 hours without needing to be wound.

The Complication: Annual Calendar

In 1925, 17 years before Alan Turing cracked the Enigma code, Patek Philippe cracked the perpetual-calendar wristwatch, making a timepiece that kept track of the day, month, and year without drifting out of sync every short month or leap year. Because of how complex the mechanism of this function is, perpetual-calendar watches are incredibly expensive. They’re also among the most spectacular models ever manufactured, like the famous Patek Philippe pocket watch made for Henry Graves in 1932, which sold at auction for $24 million in 2014. It wasn’t until 1996 that the much more affordable annual calendar entered the scene—the only thing these don’t do is automatically correct for February’s 28 days, so they have to be adjusted once a year. Annual calendars may not have quite the same prestige (though either complication requires the expertise of the world’s best watchmakers to execute), but they come without the extreme price and fragility of perpetual calendars. Both types are often adorned with additional complications, like the Girard-Perregaux 1966 Annual Calendar and Equation of Time (released in 2009), pictured above ($33,400), which also shows the time as it would appear on a sundial.

Even a perpetual calendar needs to be adjusted, since leap years are skipped at the turn of a century. The next time will be in the year 2100.