A Beginner's Guide to Watch Complications

In watchmaking, a complication is any function beyond telling the hours, minutes, and seconds. Even a simple date window counts. Complications add interest and utility, and they also add cost and servicing needs.

A date or day-date display is the most common complication and the most useful. If you check the date often, it is worth having. Just be careful when setting it near midnight, because the mechanism can be damaged if you change the date in the wrong hours.

A chronograph is a built-in stopwatch, usually with start, stop, and reset pushers and extra subdials. It is popular on sports watches and pairs well with a tachymeter scale. Chronographs are thicker and a little more complex than three-hand watches, but they are a classic for good reason.

A GMT or dual-time watch shows a second time zone with an extra hand, usually on a 24-hour scale. It is the most practical complication for frequent travelers and anyone who works with people in other countries. A true GMT lets you jump the local hour hand without stopping the watch.

A moon phase display shows the current phase of the moon in a small aperture. It is mostly romantic rather than practical, but a well-made one is beautiful and needs adjusting only every few years.

An annual calendar tracks months of different lengths and needs a correction once a year, at the end of February. A perpetual calendar goes further and accounts for leap years too, which is why it is considered a high point of mechanical watchmaking and sits at a much higher price.

At the top end are tourbillons, minute repeaters, and split-second chronographs. These are admired for the craftsmanship involved more than for everyday usefulness.

Choose complications you will actually use. A watch with fewer functions is easier to wear, easier to service, and often easier on the wallet. Use the style filters on our watches page, such as Chronographs and GMT & Travel, to see what each looks like.