It’s Complicated
Everything You Need to Know About Watch Complications

Published on 15 July 2022

A fine mechanical watch is one of the most complicated objects you are ever likely to own. The act of assembling 100s of parts, an assortment of wheels, gears, pinions and screws into a space measuring millimetres across, is already challenging. But to do this so that all the pieces continually tick out hours, minutes, and seconds is remarkable.

It turns out that time-telling is the simplest function possible in a mechanical watch. The additional functions are referred to as ‘complications’. The range of possibilities is impressive, with the most common (and perhaps the most useful) complication being the humble date display. Some of the more esoteric complications include real-time tracking of all the planets’ relative positions in our solar system or the current difference between actual solar time and standardised civil time.

All this additional complication is achieved by adding even more gears, wheels and cams into the mechanism. There are two main ways of achieving this. The first, often referred to as an integrated approach, is to design a calibre (the ‘engine’ of the watch) that incorporates the complications from the ground up. The alternative approach is to create a stand-alone complication module that fits on top of an existing base calibre. This is typically referred to as a modular calibre and is often seen as a more cost-effective approach as the watch maker isn’t required to start from scratch with each new mechanism development.

Of course, complications don’t make one watch better than any other, but they certainly add something; be that convenience, cool factor or something else entirely, here are a few of our favourite complications.

01. A stopwatch on your wrist

Chronographs are one of the most popular and distinctive complications. Essentially they add a stopwatch functionality to your watch, allowing you to measure elapsed time accurately and easily. Most chronograph watches look similar to this handsome Longines Heritage Avigation, with pushers on the side that stop, start and reset the chronograph, and register or subdials on the watch which measure the elapsed minutes and hours. One thing worth noting is that while the central second hand is used for measuring elapsed seconds, there is often a constantly running seconds hand on one of the subdials. On this Longines, it’s the register at the 9 o’clock position.

Longines Heritage Avigation | Model L28161932

02. Save the date

Where chronographs are made to measure short, sharp bursts of action, calendar complications on watches take a longer view of life, counting out the days, weeks and months. This category of complications covers a lot of options; from the date display, which tells you what day of the month it is, through to perpetual calendars, which displays the macro year data including leap years. IWC’s Portugieser Annual Calendar sits somewhere in the middle, showing the month, date and day in a striking display at the top of the dial. This calendar complication only needs to be adjusted once a year, and the watch also features a power reserve display indicating how much energy is stored within the movement.

IWC Portugieser Annual Calendar — IWC Schaffhausen Portugieser Annual Calendar | Model IW503502

03. The mystery of the moon

Chronographs and calendars are quite practical watch complications, but not all features are so down-to-earth. Some, like the moonphase display on this Jaeger-LeCoultre Rendez-Vous are more about aesthetics than utility. This watch tells you, with unerring accuracy, the current phase of the moon, be it waxing, waning, gibbous or full. It’s not a function most people need on a day-to-day basis, but it’s a charming addition to a watch that encourages us to think about our relationship to time and our place in the universe, and that’s a complication worth considering.