Complications A – Z


Lets start at the very beginning, with a brief look at the main functions your luxury watch might have.  Such functions are called complications – and its no pun intended as they do indeed make your watch rather complicated. The functions themselves are often partially hidden, work without your input and often come without instructions!  Impress your friends, and wow yourself, with the knowledge of what each one does, and is for;


Of course, you are familiar with the alarm function. Setting it to predetermined time to alert you. Some quartz watches have an alarm hand for this purpose but both quartz and automatic watches can have an alarm feature.

Originally set for pilot watches this function measures the altitude – height above sea level. It records this by reading the changes in barometric pressure in ascents and descents. Important for pilots, useful for mountain climbers, sky divers and anyone else who needs to measure such heights.

Analog/digital display.
In an anadigi, or ‘dual display’ watch both the time in arabic numbers and marked by hour and minute hands is shown. Used by the military for when exact second timing is required for synchronising, CPR and exercise training.


Battery reserve indicator.
An indicator that shows the battery in a quartz watch is soon to expire. The second hand will generally jump in two to four second increments showing the battery will fail within two weeks.


A complication that shows the day, date and month. Sometimes also the year. Watches may take into account longer and shorter months or they may need manually adjusting. Usually watches do not take leap years into account and all need a reset as these occur, However if your complication is an Atomic calendar this will take into account month lengths and leap years. These have been programmed up to 40 years into the future.

A popular type of watch, basically a watch with an advanced stop watch function. Able to show elapsed time whilst showing conventional time. Various type of chronograph are available, although most people want the feature without every actually using it.

Countdown timer.
Exactly as it say. Allowing the wearer to determine how much of a preset time has elasped.


Day/Date function.
The complication that shows the day of the week and/or date of the month.

Day/Night indicator.
A feature found mostly on watches with dual time displays, to help determine the time of day in other countries.

Depth sensor.
Found on diving watches, the depth sensor or depth meter, monitors the divers depth level using water pressure.

Dual time.
Dual time watch’s are a must for the travelling executive or anyone operating in multiple time zones. The watch measures both local time and at least one other time zone. Shown via a twin dial, extra hand or sub dial.


Equation of time.
An EOT complication shows the difference between true solar time and and manmade time. Days of the year are usually slightly longer or shorter than exactly 24 hours. This feature showcases that difference between ‘mean’ and ‘true’ time.


Helium Escape Valve
Diving watches that are actually used by professional divers in deep sea diving need the escape valve to allow the helium to slowly filter out during decompression. Otherwise the water pressure would cause a helium build up and cause the crystal to pop out.

Hourly time signal.
If activated this signal will chime every hour.


Lap timer.
A function that breaks up segments of race timing. A timer resets to zero at the end of each lap ready for the next lap. Most lap timers also have a lap memory, allowing viewing of lap times later on.

Minute Repeater.
A complication that strikes hours, quarters, and minutes using a gong. A complicated complication, usually increasing the value of a watch greatly.

Moon phase.
The most well known complication, a window showcasing the various phases of the moon. You can read more about it here.


The complication that counts the number of steps taken by its wearer. Long before apple did!

Perpetual calendar.
Taking into account the short and long months of the year, this complication shows at least the day, date, month. Many also show the year and moon phase.

Power reserve indicator.
Allows the wearer to see how long before the watch requires winding again.


A common feature in chronographs. Measures speed over a specified distance.

A horological and design wonder. By mounting parts in a rotating cage, the balance and escapement can move completely, avoiding errors caused by a change in position of the wearers wrists. Typically rotating every minute, some manufactures now provide a four or six minute tourbillon as well. Extremely difficult complication and drastically increased the cost and value of your watch.


World time complication.
Intricate complications that tell the times in 24 different time zones. These watches are called World timers.

Comments are closed here.