Wadokei57 Astronomical clock

This Apple Watch app combines a Japanese "Wa-dokei" (traditional Japanese clock) based on sunrise and sunset with the world's smallest planetarium.

The red hand at the top of the clock shows the current time.

The center hand indicates the phases of the moon and the seasons.

● Key Features
・Complications for the Moon, Sun, Venus, and traditional Japanese time
・Traditional Japanese time: A system dividing the day (sunrise to sunset) and night (sunset to sunrise) into six segments each
・Displays time periods based on the 12 Chinese Zodiac signs, synchronized with local sunrise and sunset times based on latitude and longitude
・Simulates the starry sky for locations around the world
・Time navigation by rotating the crown
・Displays a gradient on the day/night ring representing night sky brightness based on moon phase and altitude

●About WADOKEI
The ancient Japanese WADOKEI has 12 animals named for each hour of the day.

・子: Mid-night – when the Rat is most active.
・丑: Early hours of night – when the Ox is chewing the cud.
・寅: Late hours of night – when the Tiger is prowling and seeking food.
・卯: Sunrise – when the Hare and the Rabbit are busy foraging for food.
・辰: Early morning – when the divine Dragon rises to control the rain (the dawn sunrise determining the day’s weather).
・巳: Mid-morning – when the Snake becomes active.
・午: Mid-day – when the Horse cavalry return from drill.
・未: Early-afternoon – when the Sheep is eating grass.
・申: Mid-afternoon – when the Monkey becomes active hunting scraps.
・酉: Late-afternoon – when the Cock returns from the forest to roost.
・戌: Early-evening – when the Dog keeps watch.
・亥: Late-evening – when everything is quiet and the Pig or Boar forages.
(source:wadokei.org)

In this app, the hour of 酉 is set to the time of sunset.

● Celestial Simulation
・Real-time Celestial Calculation: Accurate sunrise and sunset times for your current location.
・Constellation Display: Accurately depicts over 1,000 stars and 88 constellations.
・Sun and Moon Orbits: Track the movement of celestial bodies in real time.
・Tracks the movement of Venus, Mars, Jupiter, and Saturn in real time.

●Privacy & Security
・Location Information: Used Only for Astronomical Calculations; No External Transmission
・Offline Operation: No Internet Connection Required
・Data Protection: All Calculations Performed Locally
・Battery Optimization: Long-Lasting Operation with Efficient Algorithms

● 24 Solar Terms Calendar
・Calculates and displays the 24 solar terms based on the solar orbital position
・Moon Phase Display: Precisely reproduces the phases of the moon, from new moon to full moon. Inverted left and right in the Southern Hemisphere.
・Seasonal Hand: Turn the crown to simulate seasonal changes throughout the year.

● Apple Watch Optimization
Swipe to switch between Japanese clock display, starry sky display, and settings screen.
Switch between Japanese clock display and starry sky display with index finger and thumb gestures. (Series 9 and later)
Double-tap the Japanese clock display screen to switch the kanji characters to animal illustrations.
Location support: Accurate astronomical calculations anywhere in the world.

● Expanded Starry Sky View
Observe the constellations. Turn the crown to move through time.
・The starry sky rotates in real time with the electronic compass.
・Displays the direction and altitude of the stars.
・Displays the positions of the sun and moon.

● Intuitive Operation
・Long Press: A 10-second animation of seasonal changes throughout the year.
・Swipe: Switch between Japanese clock and starry sky view.

＜ Download now >
Timeless beauty meets cutting-edge technology
Would you like to watch a millennium of time on your wrist?

This software uses the following libraries:
●SunCalc
Copyright (c) 2025, Vladimir Agafonkin
All rights reserved.
（BSD-2-Clause license)