# CAL20000 > Detailed astronomical and traditional calendar with celestial maps and astrological data. (iPhone/iPad app by YOUNGCHANG KOH.) - Source: https://appshunter.io/ios/app/cal20000/id462638410 (this page in markdown: same URL + `.md`) - Developer: [YOUNGCHANG KOH](https://appshunter.io/developer/462580655) - Category: Lifestyle, Reference - Price: Free with in-app purchases - Rating: 5.00/5 from 1 App Store ratings · 2 written reviews indexed - Age rating: 4+ - Requires: iOS 10.3 · 12 MB - Languages: American English, Korean - Released: 2011-12-08 - Data updated: 2026-06-04 - Monetization: free - User reviews in markdown: https://appshunter.io/ios/app/cal20000/id462638410/reviews.md ## What is CAL20000? This calendar is made based on the calculation of accurate sun and moon position. The effective year range is from -9999 to 10000. This calendar display a month which is just only Gregorian calendar in total effective year.(Julian calendar date do not be displayed in this calendar). On the month table, Each day cell have solar day number which is Gregroian date, lunar month/day number , sexagenary day unit(日辰 or 干支), star letter of 28 mansions(二十八宿). These data of a day have been used very long period which is maybe from more than 5000 years ago to now and currently is used widely in Korean and Chinese real life. And also it is indicated the 24 solar terms, new/full moon time with eclipse occurrence and it's floating Julian day number for verification of accuracy. - Kusung(九星) Calendar and KiMoon(奇門) Calendar Information is added. The relation information is here(Korean). The year range for Kusung and Kimoon is 1880~2055. - The decade luck and it's change time, the ten celestial stems in month time are displayed with very precisely value. - The Korea era(檀紀) and Buddha era(佛紀) are added. - Moon orbit information is added. The informations are new moon, full moon, first quarter, last quarter, Apogee, Perigee, Ascending node, Descending Node every exact time, the distance between earth and moon and its rate, solar/lunar eclipse occurance. - Islamic Year and Month(Hijra) is added. - Easter date is added. - The Julian calendar date is displayed before Oct 1582. - Chinese character is used as possible as can be expressed for Sinosphere people. - Web link for the eclipse material which are solor/lunar eclipse information and map on NASA eclipse site are added. - V2.0 SKYMAP add Add North/South Pole/current position centirc skymap and Heliocentric planet postion map. Around 9000 stars based on Yale bright star catalog are shown on this skymap. Sun/Moon/Plants postion and trace are shown as assigned time/period. Sun/Moon/Planets events are calculated realtime and shown its time and position such as Conjunction/New Moon, Opposition/Full moon, quadrature/quarter, great elongation, statrionary(reverse start/finish), ascending,descending node, perigee/perhelion, apogee/aphelion, planet conjunction and 24 solar term. ## Key features - Accurate sun and moon position calculations - Lunar phase and eclipse tracking - Sexagenary day unit and 28 mansions data - 24 solar terms and new/full moon times - Kusung and KiMoon calendar information - Moon orbit and distance data - Heliocentric planet position map ## Pricing and in-app purchases Base price: Free. **One-time purchases** | Purchase | Price | Type | | --- | --- | --- | | 유료버전 | $99.99 | one-time | | 1 week limited version | $0.99 | one-time | ## Recent user reviews (2 of 2) All indexed reviews: https://appshunter.io/ios/app/cal20000/id462638410/reviews.md ### 5/5 — Love this app *2014-07-03* Just downloaded it. My Chinese is limited but I can easily see the equivalent day in gregorian or lunar calendar. The blue numbers in each day tells you the lunar month and day. For example 8.27 means the 27th day of the eighth month of that lunar year. It's also easy to swipe to advance the calendar months. ### 5/5 — 고영창님 훌륭해요~~ *2013-08-06* 감사합니다. 잘 보고, 쓰고, 공부할께요~~ ## Frequently asked questions about CAL20000 ### What is the effective year range for CAL20000? CAL20000 offers an extensive effective year range from -9999 to 10000, displaying Gregorian calendar dates within this period. ### Does CAL20000 display Julian calendar dates? Yes, CAL20000 displays the Julian calendar date before October 1582. After this date, it exclusively shows the Gregorian calendar. ### What traditional calendar information is included in CAL20000? CAL20000 includes the sexagenary day unit (日辰 or 干支), the star letters of the 28 mansions (二十八宿), and the 24 solar terms, which are widely used in Korean and Chinese culture. ### Can I view celestial maps with CAL20000? Yes, CAL20000 features a SKYMAP that displays approximately 9000 stars from the Yale bright star catalog, along with North/South Pole-centric and Heliocentric planet position maps. ### Does CAL20000 provide information on moon phases and eclipses? Absolutely. CAL20000 provides exact times for new moon, full moon, first quarter, last quarter, apogee, perigee, ascending node, and descending node, along with solar/lunar eclipse occurrences. ### What astrological information does CAL20000 offer? CAL20000 includes Kusung (九星) Calendar and KiMoon (奇門) Calendar information for the years 1880-2055, as well as decade luck and its change times, and ten celestial stems in month time. ### What is the update frequency for CAL20000? The latest version of CAL20000 was last updated on November 25, 2020. While specific update frequency isn't detailed, the app has seen significant version updates. ### Is CAL20000 available on multiple devices? CAL20000 is supported on iPhone, iPad, and iPod devices, making it accessible to a wide range of Apple users. ## Version history (last 5 releases) ### 3.5 — 2020-11-25 Add Many thing such as Occultation time/postion on day info/starmap, Moon orbit, new type of star map - Equinox/Equator, Sun/Ecliptic, Galactic, Korean 3-28Mansion, 88 Constellation. Input method improvement. Select time zone. Bug fix. etc ### 3.0 — 2015-08-20 This app has been updated by Apple to display the Apple Watch app icon. Milkyway, Messier Objects are added to StarMap debugging ### 2.1 — 2014-04-07 2014 April 2 Each event can be quried for planet events. Event query period is extended.(free 30days->1year, paid 1year->30years) Lunar date display for many event times. Minor bugs fixed. ### 2.0 — 2014-02-11 2014 Jan 29 SKYMAP is added. This sky map is based on Korean/Chinese Astronomical system. Sun, Moon and Planets time/position , orbits and its events such as stationary,conjunction,opposition,greatest elongation, quadrature are also drew on the sky map for all effective year range. ### 1.01.00 — 2011-12-08 No release notes. ## Apps similar to CAL20000 | App | Rating | Price | Category | | --- | --- | --- | --- | | [Химчистка EASY BREEZY](https://appshunter.io/ios/app/easy-breezy/id1593210460) | — | Free | Lifestyle | | [小游魚](https://appshunter.io/ios/app/id1628346960) | 5.0 (1) | Free | Lifestyle | | [Blount County AL Sheriff](https://appshunter.io/ios/app/blount-county-al-sheriff/id1621111800) | 4.0 (4) | Free | Lifestyle | | [5 Color Test](https://appshunter.io/ios/app/5-color-test/id1370500008) | 1.0 (2) | Free | Lifestyle | | [Saju World – Korean Fortune](https://appshunter.io/ios/app/saju-world-korean-fortune/id1551797792) | 4.3 (655) | Free | Lifestyle | | [MyToday - Diary](https://appshunter.io/ios/app/mytoday-diary/id1152234483) | 4.2 (25) | $1.99 | Lifestyle | --- *Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-06-04.*