Wadokei - Frequently Asked Questions (FAQ)

Table of Contents

1. General Questions
2. Getting Started
3. Features
4. Settings & Customization
5. Location & Time
6. 24 Solar Terms
7. Troubleshooting
8. Privacy & Permissions
9. Technical Questions
10. About the App

General Questions

What is Wadokei?

Wadokei (和時計) is a traditional Japanese timekeeping system used during the Edo period (1603-1868). Unlike modern clocks that divide the day into 24 equal hours, Wadokei divides daytime and nighttime into six equal parts each, meaning the length of an "hour" changes with the seasons.

How does Wadokei differ from a regular clock?

Modern Clock:

• 24 hours of equal length
• Fixed hour duration (60 minutes)

Wadokei:

• 12 hours that change length seasonally
• Daytime divided into 6 equal parts
• Nighttime divided into 6 equal parts
• Hour length varies by sunrise/sunset times

What devices does this app support?

The app is designed for Apple Watch (Series 4 and later) running watchOS 10.0 or later.

Is this app available for iPhone or iPad?

Currently, Wadokei is exclusively designed for Apple Watch to provide an authentic wrist-watch experience.

Getting Started

How do I install the app?

1. Open the App Store on your Apple Watch
2. Search for "Wadokei" or "和時計"
3. Tap Get to download and install
4. The app will appear on your Home screen

How do I use the app for the first time?

1. Open the app from your Apple Watch home screen
2. Grant location permissions when prompted (for accurate sunrise/sunset times)
3. The clock will automatically display using your current location
4. Swipe left/right to access different screens

What are the different screens?

The app has three main screens:

1. Settings (Left): Configure location, region, and cities
2. Main Clock (Center): Traditional Wadokei display
3. Sky View (Right): Detailed astronomical view with stars and constellations

Swipe left or right to switch between screens.

Features

What does the main clock display show?

The main Wadokei clock displays:

• Season Hand: Shows the current season based on 24 solar terms
• Day/Night Ring: Visual representation of daytime and nighttime
• Time Markers: Traditional Japanese time markers (子, 丑, 寅, etc.)
• Current Time: Displayed in traditional Wadokei format
• Solar Term: Current 24 solar term (e.g., 立春, 春分)
• Location: Current location or selected city

What is the Season Hand?

The Season Hand rotates around the clock face to indicate the current position within the seasonal cycle. It's based on the 24 solar terms and shows which season you're currently in.

What are the colored rings around the clock?

• Inner Ring (Day/Night): Shows the division between daytime (light) and nighttime (dark)
• Outer Ring (Solar Terms): Displays the current 24 solar term
• Four Seasons Circle: Visual representation of the four seasons

Can I use the Digital Crown?

Yes! Rotate the Digital Crown to:

• Manually adjust the time display
• Explore different times of day
• See how daylight/darkness changes throughout the year

The clock automatically returns to current time after a few seconds of inactivity.

Settings & Customization

How do I change my location?

Method 1: Use Current Location

1. Swipe to the Settings screen (left)
2. Tap "Use Current Location" button
3. Grant location permission if prompted

Method 2: Select a City

1. Swipe to the Settings screen
2. Select a Region (Japan, China, Asia, etc.)
3. Choose a City from the list

Method 3: Manual Coordinates

1. Go to Settings screen
2. Use the sliders to set Latitude and Longitude manually

What regions and cities are available?

The app includes major cities from:

• Japan: Tokyo, Osaka, Kyoto, Sapporo, etc.
• China: Beijing, Shanghai, Hong Kong, etc.
• Asia: Seoul, Singapore, Bangkok, etc.
• Europe: London, Paris, Berlin, etc.
• North America: New York, Los Angeles, etc.
• Other regions: Middle East, Africa, South America, Oceania

Can I add my own custom location?

Yes! Use the Manual Adjustment feature:

1. Go to Settings screen
2. Adjust Latitude slider
3. Adjust Longitude slider
4. The clock will update based on your custom coordinates

How do I reset to my current location?

Simply tap the "Use Current Location" button in the Settings screen. This will override any manual or city-based location settings.

Location & Time

Why does the app need my location?

Wadokei relies on sunrise and sunset times, which vary by geographic location. Accurate location data ensures:

• Correct calculation of daytime/nighttime division
• Accurate seasonal time adjustments
• Proper display of astronomical information

Does the app work without location permission?

Yes, but with limitations:

• The app will use Tokyo, Japan as the default location
• You can manually select any city from the list
• You can set coordinates manually

How accurate is the time calculation?

The app uses precise astronomical algorithms to calculate:

• Sunrise and sunset times (±1 minute accuracy)
• Solar term transitions (to the hour)
• Day/night divisions (±1 minute accuracy)

Does the app work in different time zones?

Yes! The app automatically adjusts for:

• Your current time zone
• Daylight Saving Time (where applicable)
• Selected city's time zone

Can I see past or future times?

Yes! Use the Digital Crown to scroll through different times. You can see:

• How daylight changes throughout the day
• Different seasons
• Past or future dates

The display automatically returns to current time after a few seconds.

24 Solar Terms

What are the 24 Solar Terms?

The 24 Solar Terms (二十四節気) are a traditional East Asian lunisolar calendar system that divides the year into 24 periods based on the sun's position. Each term represents about 15 days.

What are the names of the 24 Solar Terms?

Spring (春):

1. 立春 (Risshun) - Beginning of Spring
2. 雨水 (Usui) - Rain Water
3. 啓蟄 (Keichitsu) - Awakening of Insects
4. 春分 (Shunbun) - Spring Equinox
5. 清明 (Seimei) - Pure Brightness
6. 穀雨 (Kokuu) - Grain Rain

Summer (夏): 7. 立夏 (Rikka) - Beginning of Summer 8. 小満 (Shouman) - Lesser Fullness 9. 芒種 (Boushu) - Grain in Ear 10. 夏至 (Geshi) - Summer Solstice 11. 小暑 (Shousho) - Lesser Heat 12. 大暑 (Taisho) - Greater Heat

Autumn (秋): 13. 立秋 (Risshuu) - Beginning of Autumn 14. 処暑 (Shosho) - End of Heat 15. 白露 (Hakuro) - White Dew 16. 秋分 (Shuubun) - Autumn Equinox 17. 寒露 (Kanro) - Cold Dew 18. 霜降 (Soukou) - Descent of Frost

Winter (冬): 19. 立冬 (Rittou) - Beginning of Winter 20. 小雪 (Shousetsu) - Lesser Snow 21. 大雪 (Taisetsu) - Greater Snow 22. 冬至 (Touji) - Winter Solstice 23. 小寒 (Shoukan) - Lesser Cold 24. 大寒 (Daikan) - Greater Cold

How are Solar Terms calculated?

Solar terms are based on the sun's ecliptic longitude:

• Each term occurs when the sun reaches a specific position (0°, 15°, 30°, etc.)
• Calculated using precise astronomical formulas
• Updated automatically based on current date

Why do Solar Terms matter for Wadokei?

Traditional Japanese timekeeping was closely tied to agricultural seasons and natural phenomena. The 24 Solar Terms:

• Reflect seasonal changes
• Indicate agricultural activities
• Show cultural and historical significance
• Enhance the authenticity of the Wadokei experience

Troubleshooting

The clock is not showing the correct time

Check these items:

1. Ensure your Apple Watch time is correct
2. Verify your time zone settings
3. Check if you have the correct location set
4. Restart the app

Location permission is not working

Try these steps:

1. Open Watch app on your iPhone
2. Go to Privacy → Location Services
3. Find Wadokei and set to "While Using App"
4. Restart the app on your Apple Watch

The app is slow or unresponsive

Solutions:

1. Force quit the app (press side button, swipe right on app)
2. Restart your Apple Watch
3. Ensure you have the latest watchOS version
4. Check available storage space on your watch

The display looks incorrect

1. Check your language settings (Settings → General → Language)
2. Verify the app is up to date
3. Try changing to a different location and back
4. Restart the app

Battery drain seems high

The app is optimized for battery life, but if you notice increased drain:

1. Ensure you're running the latest version
2. Reduce screen brightness
3. Close the app when not in use
4. Check for watchOS updates

Privacy & Permissions

What permissions does the app require?

Required:

• Location Services (for accurate sunrise/sunset calculations)

Optional:

• None

Does the app collect my data?

No. The app:

• Does NOT collect personal information
• Does NOT track your activity
• Does NOT send data to external servers
• Does NOT require an account or login

Where is my location data stored?

• Location data is stored locally on your Apple Watch
• It is never transmitted to external servers
• You can delete the app at any time to remove all data

Can I use the app offline?

Yes! Once you've set your location, the app works completely offline. All astronomical calculations are performed locally on your device.

Does the app have ads?

No. The app is completely ad-free.

Are there in-app purchases?

The current version does not include in-app purchases. All features are available immediately after download.

Technical Questions

What algorithm does the app use for calculations?

The app uses:

• Meeus astronomical algorithms for sun position
• High-precision ephemeris for solar terms
• Standard timezone databases for time conversion

How is sunrise/sunset calculated?

The app calculates sunrise and sunset using:

• Geographic coordinates (latitude/longitude)
• Date and time
• Atmospheric refraction correction
• Altitude adjustment
• Time zone offset

What is the accuracy of astronomical calculations?

• Sunrise/Sunset: ±1 minute
• Solar Terms: ±1 hour
• Day/Night Division: ±1 minute
• Season Position: ±0.1°

Does the app support polar regions?

The app handles polar day (midnight sun) and polar night situations:

• In summer at high latitudes: Shows continuous daylight
• In winter at high latitudes: Shows continuous darkness
• Gracefully handles edge cases

What languages does the app support?

Currently supported languages:

• English
• Japanese (日本語)
• Chinese Simplified (简体中文)
• Korean (한국어)

The app automatically uses your device's language setting.

About the App

Who created this app?

Wadokei was created by developers passionate about preserving traditional Japanese timekeeping culture and making it accessible through modern technology.

What inspired this app?

The app was inspired by:

• Historical Japanese Wadokei clocks from the Edo period
• Desire to preserve traditional timekeeping knowledge
• Interest in astronomical calculations
• Beauty of seasonal time variations

Can I suggest new features?

Yes! We welcome feedback and suggestions. You can:

• Leave a review on the App Store
• Use the feedback option in TestFlight (for beta testers)
• Contact us through the App Store

Is the source code available?

The app is proprietary software. However, the astronomical calculation methods are based on publicly available algorithms and research.

How often is the app updated?

We regularly update the app to:

• Fix bugs
• Improve performance
• Add new features
• Support new watchOS versions

What's the version history?

Major updates include:

• v1.0: Initial release with basic Wadokei functionality
• v1.5: Added 24 Solar Terms display
• v1.10: Multi-language support
• v1.14: Enhanced city selection and regional support
• v1.15: Improved performance and App Store compliance

Additional Resources

Where can I learn more about Wadokei?

Recommended resources:

• Historical museums in Japan (Tokyo National Museum, Edo-Tokyo Museum)
• Books on Japanese timekeeping history
• Academic papers on traditional East Asian calendars
• Online resources about the Edo period

What is the historical significance of Wadokei?

Wadokei clocks were:

• Used during Japan's Edo period (1603-1868)
• Based on Chinese astronomical knowledge
• Mechanically complex devices
• Symbols of technological achievement
• Important cultural artifacts

Are there physical Wadokei clocks I can see?

Yes! Historical Wadokei clocks can be seen in:

• Japan: National Science Museum (Tokyo), various temples
• Museums worldwide: with Japanese art collections
• Private collections: occasionally displayed at exhibitions

How can I support the app?

You can support the development by:

• Rating the app on the App Store
• Writing a review to help others discover it
• Sharing with friends interested in Japanese culture
• Providing feedback for improvements

Contact & Support

How do I get help?

1. Check this FAQ first
2. Review the in-app guide (if available)
3. Contact us through the App Store
4. Join beta testing for early access to new features

How do I report a bug?

If you encounter a bug:

1. Note the steps to reproduce the issue
2. Check your app version and watchOS version
3. Take screenshots if possible
4. Report via App Store or TestFlight

Where can I find the privacy policy?

The privacy policy is available:

• On the App Store listing
• In the app settings (if applicable)
• On the developer's website

Quick Reference

Key Terms

• Wadokei (和時計): Traditional Japanese clock
• Solar Term (節気): One of 24 seasonal divisions
• Season Hand: Clock hand indicating current season
• Day/Night Division: Varying length of daylight hours
• Temporal Hour: Variable-length hour system

Useful Tips

1. Use Digital Crown to explore different times
2. Swipe between screens for different views
3. Enable location for accurate calculations
4. Select nearby city if location is unavailable
5. Restart app if display issues occur

Common Abbreviations

• UTC: Coordinated Universal Time
• JST: Japan Standard Time
• GPS: Global Positioning System
• UI: User Interface

Version Information

Current Version: 1.15.4
Last Updated: March 2026
Compatibility: Apple Watch Series 4+, watchOS 10.0+
File Size: ~10 MB
Category: Utilities, Education
Age Rating: 4+

Legal

Copyright

© 2024-2026 SEKKEN All rights reserved.

Trademarks

• Apple, Apple Watch, watchOS are trademarks of Apple Inc.
• All other trademarks are property of their respective owners

License

This software is provided "as is" without warranty of any kind. See the full license agreement in the App Store listing.

Thank you for using Wadokei!

We hope this app helps you appreciate the beauty and wisdom of traditional Japanese timekeeping.

For the latest updates and information, visit the App Store page.