Sunrise and sunset is a complication that shows the local times at which the Sun rises and sets. It has mostly appeared in rare, highly complicated watches. Very few brands make wristwatches with it. The times depend on latitude, because a place’s north-south position sets how long its day is.
Where it comes from
Famous early examples are the pocket watches made for James Ward Packard in 1927 and for Henry Graves Jr. in 1933. The Patek Philippe Star Caliber 2000 shows sunrise and sunset times among its many functions. German watchmaker Martin Braun made a version that shows the local times of sunrise and sunset. He named it Eos, after the Greek goddess of dawn. On Vacheron Constantin’s Solaria, the solar display goes further. It shows sunrise and sunset times, the length of the day and the position of the Sun in the sky.
How does a sunrise and sunset display work?
Sunrise and sunset times change through the year and from place to place. In Patek Philippe’s Celestial ref. 6105G-001, two cams drive the readings. Each cam turns once a year. The usual design relies on a fixed cam. Krayon’s Anywhere uses a rack-and-yoke system instead, so the display can be set for different places. A watchmaker sets it to one chosen place by adjusting screws.
Does it show summer time?
Usually not. These displays normally show standard, or winter, time. In summer the wearer has to add an hour to each reading. Patek Philippe’s Celestial ref. 6105G-001 deals with this through a pusher that switches the readings between summer and winter time. The brand calls this a world first. The ref. 6105G-001 is also Patek Philippe’s first wristwatch to show sunrise and sunset times directly all year round.
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