Comparison

Monad Calendar Clock vs Solar System Viewer

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Monad Calendar Clock

This app visualizes time through planetary and celestial movements, contrasting natural rhythms with mechanical time. It offers unique perspectives on Earth's position in space and time, showing star and planet locations, seasonal changes, and lunar phases.

Highlights
  • Planetary time and date display
  • Celestial ring visualization
  • Heliocentric and Geocentric modes
  • Star and planet location tracking
  • Seasonal and lunar phase progression
  • Twilight and sunrise/sunset times
  • Event scheduling
Features
Currently charting
Read full description

MONAD does something that no other clock or calendar does; it tells the planetary time and date – the solar day, lunar month & seasonal year. MONAD reveals your unique place (and perspective) in planet-centered space and time. MONAD demonstrates the biorhythms of the Earth’s biosphere, and it integrates two types of time: 1) Natural time, which is cyclic, variable, and alive, with 2) Mechanical time, which is linear, highly regular, abstract and artificial. MONAD represents a paradigm shift of planetary proportions; A New Paradigm of Time With MONAD, you see the natural rhythms of time­ proceeding in endless circles and spirals. MONAD shows the location of the stars and planets; what’s visible at night from your location on Earth. MONAD shows the progression of the four seasons and the phases of the Moon; the obliquity of the ecliptic and the Earth’s circle of illumination, and a Twilight Dial tells you the time of Sun rise and Sun set at any latitude and time of year. MONAD shows the agricultural biorhythms of the Earth’s photosynthetic biosphere. MONAD restores the Earth, and the Earth’s biorhythms and biosphere, back to the center of our collective attention and awareness. With MONAD you see the Earth globe from an unusual perspective; the north (or south) polar axial perspective. MONAD automatically places a time zone-spanning Hour Hand at your location on the globe, marking your longitude & latitude, and you see all 24 time zones, all around the globe at the same time, the whole world interconnected. MONAD has four main Modes of operation. Geocentric (Geo) Mode features planet Earth at the center of a time and date-telling, 3-dimensional celestial ring. The algorithms and programming which drive all of the astronomical activity is based on a Sun-centered and highly accurate model of the solar system which you can access in Heliocentric (Helio) Mode. Accelerate through time, into the past or future, and watch how the configuration of the solar system changes. Shift back and forth from Geo to Helio Modes, and it’s easy to see how the two perspectives are related. It’s easy to see how and why the planets have apparent retrograde activity from an Earth-centered perspective. There is so much to explore and learn in MONAD. Astro Mode features a 2-dimensional Calendar-Clock face, which makes it possible to set the time by dragging the hour hand around the dial, or you can set the date by dragging the calendar band, or zodiac band, past the Sun’s meridian or date indicator fixed at noon at the top of the dial. A Table at the top of the screen lists the precise location of the Sun, Moon and planets at any time and date, so basically this Astro screen is equivalent to an astronomy or astrology chart, at any moment in time. Astro Mode will eventually feature a Scientific Astrology Program and an Educational Astronomy Program. Event Mode is where you record and schedule personal events, in the context of important and memorable planetary events we all share. Color-coded Event Wedges are shown in the context of the 4 corners of a solar day (Sun rise, noon, Sun set & midnight), the 4 corners of a lunar month (full and dark Moon, waxing and waning half Moons), and the 4 corners of a seasonal year (equinoxes & solstices). Another unique feature of MONAD is that you can record events “in the Now,” which encourages more presence in your life. A Health Event Mode allows you to see your personal, endocrine biorhythms in the context of planetary biorhythms we all share. The 24 hour circadian Calendar-Clock face is ideally suited to organize and display health events. If you choose to have MONAD integrate with the Apple Health app (HealthKit); then health data (e.g. Sleep period and Steps) read from HealthKit is used for display within the MONAD app. MONAD is beautiful, educational & transformative, and it will change the way you see the world around you, and your place within it. MONAD – A New Paradigm of Time.

About

Solar System Viewer

Explore and simulate the orbits of planets in our solar system. This app allows you to speed up or slow down time, travel to any date, and view planetary positions. It also offers widgets for your home screen and Apple Watch complications.

Highlights
  • Simulate planetary orbits
  • Adjust time speed
  • Time travel to specific dates
  • Home screen widgets
  • Apple Watch integration
  • View planet overviews
Features
Read full description

8Planets is a simple viewer and simulator for planetary orbits in our Solar System. 8Planets helps you discover how the planets aligned and move around over time so that you feel the scale of the Solar System or even the Universe. By giving you quick and easy access to the Solar System everywhere, 8Planets will make you feel that the Solar System is close to us. FEATURES ・Planetary Motion Speed up or slow down time to see how the planets rotate over time and grasp the scale of the Solar System. ・Time Travel Travel back or forward in time to view the Solar System or planetary positions on any given date. ・Widgets Widgets allow you to display the real-time Solar System on your Home Screen. ・Watch View the Solar System on your wrist and use Digital Crown to travel back or forward in time. ・Others Apple Watch Complications, Overview of the planets, Option to show Pluto, Sharing your favorite moment of the Solar System, URL Scheme, and more.

Screenshots

Monad Calendar Clock4 screens
Solar System Viewer3 screens

Verdict

The call

The clearest difference is review sentiment: Solar System Viewer at 83% against Monad Calendar Clock's 22%. Solar System Viewer also leads on rating (4.4 vs 3.7). Monad Calendar Clock's advantage is in-app purchases (none vs 4) and chart position (#169 vs unranked). On ratings volume, update cadence, ads and monetization model 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

CostPrice · In-app purchases · Ads · Monetization

Monad Calendar Clock costs $0.99 and Solar System Viewer $2.99 up front. Solar System Viewer sells 4 one-off in-app purchases. Monad Calendar Clock asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

Solar System Viewer holds the better App Store score, 4.4 against 3.7. Both are backed by a comparable volume of ratings — 14 and 28 respectively. Written reviews point the same way: 22% of Monad Calendar Clock's written reviews are positive against 83% of Solar System Viewer's.

UpkeepUpdate frequency

Monad Calendar Clock ships an update every 6 weeks, Solar System Viewer every 2 months. The most recent releases landed on October 29, 2026 and October 24, 2026 respectively.

Scorecard6 real differences · 5 level
Monad Calendar Clock versus Solar System Viewer: the parameters behind the verdict, then further details
ParameterMonad Calendar ClockSolar System Viewer
Price$0.99 — better$2.99
Rating3.7 (14 ratings)4.4 (28 ratings) — better
Positive reviews22.2% of reviews83.3% of reviews — better
Number of ratings1428 — better
Update frequencyEvery 6 weeks — betterEvery 2 months
AdsNoNo
In-app purchasesNo — betterYes
MonetizationPaidPaid
Best chart rank#169 — better—
DevicesiPhone, iPad, iPodiPhone, iPad, Mac, Apple Watch — better
Requires iOS13.0 — better26.0
Further details — not scored
Size266 MB22 MB
Age rating4+4+
DeveloperEarth at the Center LLCBLUE COMET LABS LLC

Customer experience

Monad Calendar Clock

All ratings14 ratings
Positive64.3%
Neutral7.1%
Negative28.6%
Written reviews9 reviews
Positive22.2%
Neutral11.1%
Negative66.7%

Solar System Viewer

All ratings28 ratings
Positive85.7%
Neutral3.6%
Negative10.7%
Written reviews6 reviews
Positive83.3%
Neutral16.7%
Negative0.0%

In-app purchases

None

Monad Calendar Clock

No in-app purchases

4 purchases

Solar System Viewer

One-time4
  • Io Tip$1.99
  • Europa Tip$3.99
  • Ganymede Tip$5.99
Show 1 more
  • Callisto Tip$9.99

Questions

Is Monad Calendar Clock free?
Monad Calendar Clock costs $0.99, with no in-app purchases.
Is Solar System Viewer free?
Solar System Viewer costs $2.99, and also offers in-app purchases.
Which has better reviews, Monad Calendar Clock or Solar System Viewer?
Solar System Viewer is rated higher. Monad Calendar Clock averages 3.7 out of 5 from 14 ratings, while Solar System Viewer averages 4.4 from 28 ratings.
Do Monad Calendar Clock or Solar System Viewer have ads?
Neither Monad Calendar Clock nor Solar System Viewer shows ads.
Which is updated more often, Monad Calendar Clock or Solar System Viewer?
Monad Calendar Clock ships an update every 6 weeks, and Solar System Viewer every 2 months. Most recently, Monad Calendar Clock was updated on October 29, 2026 and Solar System Viewer on October 24, 2026.

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