Daimyo Clock vs Citizen Sky View
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Daimyo Clock
Experience traditional Japanese timekeeping with this app, which recreates a 17th-century mechanical clock. It accurately displays time divided into six equal periods for day and night, adjusting for seasonal changes in daylight.
- Traditional Japanese timekeeping
- Day/night divided into six equal periods
- Seasonal daylight adjustments
- Accurate solar noon calculation
- Location-based time display
- Twilight start/end calculation
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Daimyo clock is a recreation of a mechanical clock developed in the seventeen century based on western clocks but modified to show traditional Japanese time. Traditional Japanese time divides the day and night into six equal periods from dawn to dusk and dusk to dawn respectively. Over the course of a year as the daylight and nighttime periods lengthen and shorten, the length of these six day or night periods change. Unlike Western clocks which are regulated by a single pendulum and run at a constant speed day or night, Japanese clocks incorporated two pendulums, and switched between them at dawn and dusk. Adjustment for the changing daylight and nighttime hours was accomplished by adjusting the effective length of the pendulums, normally done every two weeks, or twenty-six times a year. This kept the time shown on the clock reasonably close to the correct time, provided that the clock had been set correctly initially. This modern implementation is much more accurate and precise than the original clocks. In this implementation, the biweekly adjustments of the mechanical clock are made continuously, thus the day or night period length are always correct. Noon on the clock will, if location services are enabled, occur when the sun is at the zenith, or solar noon. Day start and end correspond to the beginning or end of twilight, and are calculated accounting for the refraction of the Earth's atmosphere. There are three situations where the clock my not show the local time in the Japanese manner: 1. If location services are off, Daimyo Clock will show the time for Tokyo, Japan. 東京 will be displayed on the clock face in this case. 2. While the application is obtaining an updated location after launch or returning to foreground. 3. Near the North or South poles the sun may either be above the horizon or below it for the entire day (24 hour period). In this case, the Japanese definition of time no longer applies, so the clock face will be shown without a clock hand.
Citizen Sky View
Participate in a NASA-sponsored citizen science project to study cloud formation. Coordinate with the project team for events, then use your phone to capture images of the sky at assigned locations and times. Your contributions help researchers learn more about atmospheric science.
- Citizen science participation
- Cloud formation research
- Event coordination
- Location-based image capture
- Data contribution for research
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This application is for a citizen science project being developed at the University of Colorado at Boulder. It is sponsored by NASA and NCAR. The project requires you to coordinate with the project team to attend our upcoming events where you will be assigned a location to be at a specific time. During the event, you will have oriented your phone and placed it upside down so that it can take pictures every 30 seconds until the event is over. The team will then take these images to learn more about cloud formation.
Screenshots
Verdict
The clearest difference is rating: Citizen Sky View at 5.0 against Daimyo Clock's 4.0. Citizen Sky View also leads on update cadence (every 2 weeks vs every 37 months) and iOS requirement (10.3 vs 16.0). On price, ratings volume, ads and in-app purchases there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. Neither carries in-app purchases, so what you see is what you pay.
Citizen Sky View holds the better App Store score, 5.0 against 4.0. Both are backed by a comparable volume of ratings — 1 and 1 respectively.
Daimyo Clock ships an update every 37 months, Citizen Sky View every 2 weeks. The most recent releases landed on October 4, 2026 and October 9, 2026 respectively.
| Parameter | Daimyo Clock | Citizen Sky View |
|---|---|---|
| Price | Free | Free |
| Rating | 4.0 (1 ratings) | 5.0 (1 ratings) — better |
| Positive reviews | 100.0% of reviews | — |
| Number of ratings | 1 | 1 |
| Update frequency | Every 37 months | Every 2 weeks — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free | Free |
| Devices | iPhone, iPad, Mac | iPhone, iPad, iPod |
| Requires iOS | 16.0 | 10.3 — better |
| Further details — not scored | ||
| Size | 1 MB | 26 MB |
| Age rating | 4+ | 4+ |
| Developer | Douglas Hildum | University of Colorado Boulder |
Customer experience
Daimyo Clock
Citizen Sky View
In-app purchases
Daimyo Clock
No in-app purchases
Citizen Sky View
No in-app purchases
Questions
Is Daimyo Clock free?
Is Citizen Sky View free?
Which has better reviews, Daimyo Clock or Citizen Sky View?
Do Daimyo Clock or Citizen Sky View have ads?
Which is updated more often, Daimyo Clock or Citizen Sky View?
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