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Years(Thank you,British: year) IsTime OfunitIs one of theSpring:-Summer: -Fall:-Winter:Or(I.e.-(I.e.To say(I.e.It's been a year.. OriginallySpring equinoxBased on(I.e. Celestial sphereGo aroundcycleAnd on average about 365.242 189Day(As of 2015) (Sun year).
One year longcalendarHow to define byCalendarAnd now世界Used in each countryGregorian calendarIn the (current calendar), one year is 1 days, but one year is 365 days.leap yearBy setting 400 times in 97 years, the average number of days in a year will be 1 days..
Year isTimes of DayIs a category that displays, and also serves as a unit that represents the number of years.. this isEnglish The same applies to the year of "4 years old" (4 years old) and "per year" (per year), as well as "year 1" (1950) and "the years of" (-year of-). It is also used to indicate a specific time, such as (-era)... According to the calendar system, the method of expressing the "year" of time isChronologyAndChrist era (AD)Is used in most countries,International Standards Organization OfISO 8601Then.Arabic numeralsSpecified to be written in 4 digits.
In addition, the Christian era and the original calendar era may be written together.,News (Chinese)Take, for example,JapanThen AD2020/AgainstEraUsingReiwa2 years".. In other Asian countries, in the Republic of China (Taiwan), "Dr. 109" (Union News), Democratic People's Republic of Korea (north korea)main body109 years" (Korean News),South Korea(Korea)Dan4353 AD” (Chosun Ilbo),Islamic countryButEgypt(Al Ahram) AndEur-lex.europa.eu eur-lex.europa.euTaking (Britable Ney) as an example,Hijra lunar calendar1442 years"Is also written.
"Year" isastronomyInJulian yearexcept,MeasurementNot familiar with typical uses..The reason is, for example, the currentGregorian calendarThen,leap yearBecause there are 1 days or 365 days in a year, the number of days (or seconds) is not constant.[Annotation 1]..Furthermore, to match the time with the rotation of the earthLeap secondIs also corrected byBecause.
The year is generally accepted as a rough unit of time. this isA humanSurroundingEnvironment,LifeBringPeriodicityPrioritize and then receivesenseComes from respecting. Such coexistence of cumulative time (seconds) and repeating time (years) is an example of unit flexibility and diversity..
JapaneseSo "toshi" means "Rice"穀物TheEtymologyAnd every yearRice cultivationIt is said that it came to be used in the meaning of "year" because it was doing. By the way,漢字"Year" adds the symbol of the person who has the meaning of tenacity to the grain and expresses the cycle until the grain matures..
地球What is the length of one year in living above?Spring Summer Autumn WinterRefers to the period during which the season goes around. And this is the height of the sun as seen from the groundDaylight hoursIs brought about by the change of. The sunCelestial equatorFrom about 23.44Every timeInclinedeclipticIs passing through.spring equinoxとAutumn equinoxThe celestial equator and ecliptic overlap, butSummer: The sun passes through a position that is up to about 23.44 degrees higher than the celestial equator,Winter:On the contrary, it goes up to about 23.44 degrees lower. Along with this, the sunshine hours also change, day and night are almost the same in spring equinox and autumn equinox, daytime is long in summer and short in winter. The height of the sunsunlight OfAngle of incidenceDecided to be higher in the summerSurfaceUnit ofareaPer hitEnergyThe amount increases. In addition, longer sunshine hours in summer also increases energy. In winter these work in reverse, resulting in a season.
Astronomically, one cycle of this season is from the equinox to the next equinox.Sun year(Return year) Called. This apparent sun operationrevolutionOf the earthAxis of rotationIt occurs because the (ground axis) is inclined about 23.44 degrees with respect to the revolution surface. this isEquatorial tilt angleIs said. From the position where the earth is at the equinox of the sunOrbit around the sunIf you go around the (revolution orbit) almost once, this tilted axis with respect to the sun will be in the same position., The sun again reaches the equinox. This is one season.
However, the rotation axis and revolution time of the earth are not constant. The tilted axis of rotation of the earth isTopTo touch thatdirectionTherefore, the vernal equinox is about 1 per year.secondEachto East MalaysiaHave moved to. this isPrecessionと 呼 ば れ る..Therefore, in fact, the position of the earth on the revolution is not fixed in the solar year based on the return to the vernal equinox, and the angle is about 1 seconds opposite to the direction of the earth's revolution in one year (revolution time is about minus 50).Minute).. This is the spring equinox that shifts year by year, andstarMake星座Is observed as a phenomenon in which the position of.. The “year” when the earth orbits the orbit accurately 360 degrees isInertial system) As the time when the position regressed, which isStellar yearと 呼 ば れ る.
Effects of perturbations
The revolution of the earth that determines the year in basic astronomyKepler's lawFollowElliptical orbit, And if the precession is also constant, it seems that there will be no change in the solar and stellar years. However, Kepler's law describes the motion of two celestial bodies.Newtonian mechanicsAnd the third celestial body is added here, the calculation becomes very complicated.approximationYou will only be asked for it. The disturbance of the orbit due to the influence of other celestial bodiesperturbationCalled.Simon NewcombDescribed the effects of these perturbations as short periods (short period terms) and slow periods (more specifically long period terms and long term terms), and they intermittently affect the initial value of Kepler motion... And the orbit of the earth is gradually changed by this perturbation.EccentricityIt was explained that.. Furthermore, the perturbation isNutationAnd cause a disturbance in the revolution speed and affect the stellar year.
Also, the orbit itself is not constant. The orbit of the ellipse also rotates due to perturbations from other planets,PerihelionWill shift to the earth's revolution direction by about 1 seconds (revolution time about 11 minutes) in one year.The time from passing the perihelion to the next arrival of the earth at the perihelion position is the "perigee year" (average about 4 days). ), but this year is about 4 minutes longer than a star year.
Changes in rotation
On the other hand, when the “year” is defined by the “day” determined by the rotation of the earth, it is known that the rotation itself is gradually decelerating. Perturbations andtidalIt is believed that the influence ofeclipseRecord orCoral組織It has been found that the day about 5 million years ago was short, and it is thought that the year at that time was about 1 days..
Artificially defined year
It is thought that the idea of the season was the basis of the early human being's perception of time. this isHunting and gathering societyIt has had a great influence on the factors that influence the prey and harvest. However, it is not clear how exact the concept of "year" was at that time..United KingdomIt is in新石器時代Ruins ofStonehengeIs a kind of astronomical observatory,summer solstice,winter solsticeKnow whenカレンダーIt is thought that it had the function of
Lunar Calendar and Lunar Solar Calendar
When recognizing daily,Month Phase (phase)It was convenient to wake up. From thereNew moonIs the period from to the new moon 1SakumotsukiIt is a calendar based on (about 29.53 days)Lunar calendarDeveloped.. In this calendar, the average moon (about 29.53059 days)) To 1 or 29 days per month, 30 times that (Lunar year = about 12 days))calendar yearHowever, there is a gap of about 10 days each year from the seasonal circulation. This calendar isNomadic people,FishingSuitable for central societies, in the regionAncient mesopotamia,Egypt,Greek,ChugokuDeveloped in.. Used in Islam even todayHijra calendarIs the lunar calendar, with 1 or 354 days in a year.
However, the lunar calendar has a great gap with the seasons,climateThere is a big sense of discomfort with the sense of time rooted in changeDifficult to use. Ancient greek mathematicianMetonFound almost matching 19 solar years and 235 lunar months, 19 times in 7 years of the lunar calendarAdditional month (leap month)InsertMeton cycleInvented..According to this, the average year is 1 days.This cycle isBabylonia[Annotation 2]And also found in China independently, the solar year and lunar calendarOkabo methodAdjust to make a specific year 13 monthsLunar solar calendarDeveloped.
Based on the revolution of the earthsolar calendarEgypt is an ancient civilization that developed. Occurs in the root developed in this land for a certain period of timeNile RiverThere was a flood of. Based on this, the seasons were divided into three periods, called Aketo (flood), Peroeget (budding), and Shom (deficiency)... The lunar calendar was also used in Egypt at the beginning, because this period is almost the same as the 4th moon.. However, in the summer when floods begin to occur in the eastern sky just before the sun rises.SiriusIs said to shineAstronomical phenomenonI noticed. The Egyptians神Sopdetと崇め、夏至を基準とする暦法を作り出した。当初、これは朔望月を基準に3年に1度閏月を加える1年を354日とする「太陰星暦」とも呼べる暦法だったが、紀元前2700年ごろに1か月を30日とし別に5日の祭日を設けた1年を365日とするSirius calendarWas changed to..Ancient Ethiopia has a calendar system in which 30 days, which is 12 times more than 5 days, is set as one year.,Ancient indiaPersianWas also used. In ancient Egypt, it was recognized that there was a slight difference in the operation of Sirius and the sun.Ptolemy IIIDuring the reign, a leap day was added once every four years, and a calendar system was enacted with an average of 4 days per year..
Republic RomeSeized the real power ofGaius Julius CaesarIntroduced the Egyptian solar calendar in 46 BC, with an average of 1 days per year[Annotation 3]..After his death, he was temporarily confused and operated for an average of 3 days with a leap year once every three years, but in 1 AD.AugustusCorrected and averaged back to 365.25 days.Roman EmpireWith the expansion of the Julian calendar, the Julian calendar was used almost all over Europe and in a wide area from northern Africa to the Middle East...Even in this Julian calendar, it was about 1 minutes and 11 seconds longer per year, so the error from the vernal equinox became noticeable. 14,PopeGregory XIII400 times in 97 yearsleap yearTo provideGregorian calendarThe calendar was changed to 1 days in one year.This yearly unit is initiallyCatholicIt was only adopted by countries. However, the superiority of the calendar is gradually recognizedProtestantSince the 18th century,Greek Orthodox ChristianityCountries also in the 19th century, in non-Christian countries 1873Japan [Annotation 4]Adopted by most countries around the world during the 20th centuryADIt came to be used as (World Standard Calendar).
- Mayan calendar
MesoamericaIn civilization, the solar calendar was established independently of Egypt. In Mesoamerica, the calendar of which the 20th month consists of 18 and 5 extra days is 365 days, and the 1-day numerical cycle and the 13-day day name cycle move separately. A religious calendar was used.
Julius all day
Date (year, month, day) and number of daysChange of calendarThe standards devised for various defects resulting from the fact that they are not unified by the time period and each regionJulius all day(Or "Julian day").. Julius all day long,4713 BCJanuary 1 (or January 1, 4712)noonIt is a whole day starting from. Carried out in 1582Julian calendarからGregorian calendarToChange of calendarFear that it will cause various confusion,) (1540/-1609/) Devised.
1 yearsHalf6 months is called "half year (Hantoshi, Hannen)". Also,fiscal yearAnd so on年度Is divided into six months each, and the first half (first half) is called "first half (kamihanki)"., The second half of the year (the second half) is "the second half of the year"Also called.Furthermore, the one that divides one year into quarters of three months is "QuarterPeriod" (Quarter, English: quarter), Called the first quarter, second quarter, third quarter, and fourth quarter in order from the beginning of the year or year.English-speaking countriesIs abbreviated as "Q1,Q2,Q3,Q4".
- SI prefixの 使用
- 1000 years ka (short for kilo annum, annum isLatinMeans year), ky, kyr
- 100 millionYear Ma, My, Myr,
- 10 billionYear Ga, Gy, Gyr
Crustal movementTo represent a very slow speed,Mm“Every year” (mm/y, mm/yr), “Centimeter“Every year” (cm/y, cm/yr) is used.resourceThe amount of output such as "TEvery year" (t/y, t/yr) etc. are used, but it is often regarded as an obvious thing and the term "ton" etc. Various other quantities are calculated per year, but are often omitted each year.
- Light years
Beginning of the year
The beginning of the current year) IsNew Year(January 1), but it has no astronomical or religious/ideological meaning. Became the basis of the Gregorian calendarRoman calendarSo, when it started in 735 BC, the beginning of the year is now3 (Martius) I put it on the first day.. laterGaius Julius Caesar(Julius Caesar)EgyptIntroduced fromsolar calendarIn 47 BC, when I switched towinter solsticeWas close to 1 The fact that the first day of (Januarius) was changed to the beginning of the year has been carried over to the present...In Japanese, calendar month names are counted in ordinal numbers such as January and February.Western calendar month nameIs not.The 12 unique names that go around, "which is the beginning of the year," are not always self-evident, and there is freedom in whether Martius is the first calendar month or Januarius is the first calendar month of the year (this is the day of the week). In a language that does not count週It is similar to that there is a discussion about whether "starts from Sunday or Monday").
However, the beginning of the year varied depending on the culture and ethnic groups.TemperateIn the region, the winter solstice and spring equinox, or the summer solstice (Egypt and Greece), autumn equinox, which correspond to the miles of solar operation (Jewish calendar) Was set as the beginning of the year.SumerHowever, since the calendars were not unified for each city, there were many spring equinox at the beginning of the year, but there are also cities with the summer solstice and autumn equinox at the beginning of the year., Was unified into the calendar with the beginning of the spring equinoxBabylon 1st DynastyWas the era of.. In agriculture-centered societies, spring was often regarded as the beginning of the year, as in the Roman calendar... In other solar calendars, the current Ethiopian calendar begins September 9-11., Persian calendar that started on August 8, The current September 9-22 was the beginning of the yearFrench Revolutionary Calendar(November 1793, 11 to December 24, 1805, the day corresponding to New Year's Day was Vendemiere (Grape Moon) 12st).
In medieval Europe, the Julian calendar was basically used, but at the beginning of the year, it was scattered depending on the region. They are mainlyキ リ ス ト 教Choose a day that is important toJesus ChristBirthdayIsChristmas OfMay 12,Annunciation OfMay 3, And most important in Christianity, could not be fixed in the solar calendarEaster.. January 1Lord's Circumcision FestivalWas set at the beginning of the year, but it was not common.
In 1564France OfCharles VIHowever, the beginning of the year is close to the winter solsticeFixed to January 1.. Initially there was a domestic backlash, but three years later it was adopted by the Parliament and officially issued, and this was again set when the Gregorian calendar was adopted in 3... However, this provision did not immediately spread to the Christian sphere, for exampleUnited KingdomFirst started January 1st in 1.
In history and astronomy, for a long time based on some conceptProper nounIs sometimes referred to as "what year".The Ancient Greek OfphilosopherPlatoHistoryI thought that it would circulate, and in "Theaetetus", I calculated the cycle as 36,000 years. 36,000 is called the "perfect number", which is called "magnus Platonicus annus", "great year", "Platonic Year", "Platonic Revolution". Called, The time it takes for eight celestial bodies (the sun and seven planets) orbiting the earth to return to their original positions, and was thought to be the holy cycle of the renewal of the universe.
In modern times, the name "great year" is given to the approximately 26,000 years when the vernal equinox moves around due to the precession movement.. further,Solar system per secondAt a speed of 200kmGalaxyFor about 2 million years, which is a period ofGalactic year Called (Galactic year).
Revolution of other planets
Since the year is based on the earth's revolution cycle,惑星The notation "year" is also used for the revolution cycle of. For example, "MercuryYear",火星One year"And so on.When using these terms, the year of the earth is also called the "earth year" to avoid confusion..
Astronomical unit standards
: 2π / k = About 365.256 898 days.k TheGaussian attraction constantで k = 0.017 202 098 95 (defined value). Long time agoAstronomical unitUsed to convert.. Now (after August 2012)Astronomical unit TheGaussian attraction constantExactly 149 597 870 700 m.
- ^ Used before the introduction of the Gregorian calendar in JapanTemporary calendarIsLunar solar calendarBecause one year is 1 months or (Leap month(Including) It is not constant at 13 months.
- ^ In ancient Babylonia, six months was set as one year.Therefore of the personageWas counted more than twice the present.BibleThere is a theory that this habit reflects that the characters in the are very long-lived. (Okada et al. (1994), pp.300-301, lunar solar calendar, Babylonian calendar）
- ^ For this calendar reform, 90 leap days were set, and one year became 1 days.This year was called Anus Confusionis (meaning "turbulent year"). (2005 History / International Friendship Association）
- ^ In JapanMeijiDecember 5rd, 12th is designated as January 3st, 6 of the new year, and this isMeiji eraCalled.Ohte ShigenobuAccording to his memoirs, this was aimed at saving the tight financial situation at the time by reducing the monthly salary of officials by a calendar reform. (Sato (2009), pp.55-56In addition, since the 6th year of the Meiji era in the lunar calendar was a leap year of 13 months, "the amount for December of the 2th year of the Meiji era, which was broken because there were only two days, and the 5th year of the Meiji era, which improved without preparation.Leap monthA total of two months' worth (salary) was floated. " (Blue Bucks "Science of the Calendar" Akira Yamazaki, Yoshio Kubo (2)) The description of the calendar reform method with the 1984th year of the Meiji era as 6 is not the Gregorian calendar, which was already widespread in the West at that time, but the Julius calendar. In 1873, two years before 4, when there was a discrepancy between the two, the Meiji government changed the calendar again and adopted the Gregorian calendar. Revised (Blue Bucks "Science of the Calendar" Akira Yamazaki, Yoshio Kubo (1)).Therefore, Japan adopted the Gregorian calendar in 1900.
- ^ What is a year? National Astronomical Observatory of Japan> Calendar Calculation Room> Calendar Wiki> Elements
- ^ a b Sato (2009), pp.77-81, Trial of World Unified Calendar
- ^ Masato Koyama. “Accumulation of deviations in the orbits of the earth (seasonal deviations) in the Julian calendar and the Gregorian calendar (current calendar) that improves it". Shizuoka UniversityDisaster Prevention Center. 2011/5/20Browse.
- ^ "【Year】”. Weblio Encyclopedia /SanseidoDaijirin. 2011/5/20Browse.
- ^ a b "[Year]”. Webio English-Japanese-Japanese-English Encyclopedia /Research society, JST Science and Technology Terminology Japanese-English Bilingual Dictionary, Life Science Dictionary, Japanese WordNet, etc. 2011/5/20Browse.
- ^ Sato (2009), pp.33-36, A universal era due to its own era
- ^ Sato (2009), pp.31-33, Japan date display
- ^ Sato (2009), pp.29-31, Korean date display
- ^ Sato (2009), pp.23-26, Date display of Islamic countries
- ^ a b Hiroshi Yano "Exploring the World of Units"Kodansha, 1997, 1st print.ISBN 4-06-257183-8.
- ^ "Business introduction of Japan Standard Time Project”(Japanese). National Institute of Information and Communications Technology Japan Standard Time Project. 2010/11/13Browse.
- ^ "[Year/year]”. Etymological dictionary. 2011/5/20Browse.
- ^ a b Aoki (1982), Chapter 4, Units and Ephemeris, pp.156-157, length of the year XNUMX Season
- ^ "Question 3-2 Why does the equinox day vary from year to year?". National Observatory. 2011/5/20Browse.
- ^ Shigeharu Takeno. “About the equinox". Niigata Institute of TechnologyDepartment of Computer Science. 2011/5/20Browse.
- ^ a b Kazuhiro Oyamatsu. “(PDF)". Aichi Shukutoku University. 2011/5/20Browse.
- ^ Susumu Yamaga. “Part 2-XNUMX-Science of the Universe". 2011/5/20Browse.
- ^ a b c Takao Iijima. “(PDF)". Gakushuin University. 2011/5/20Browse.
- ^ Koji Takahashi. “(PDF)". Saitama Institute of TechnologyFaculty of Human and Social Studies. 2011/5/20Browse.
- ^ Aoki (1982), Chapter 4, Units and Ephemeris, pp.159-161, length of the year XNUMX Perturbations
- ^ Aoki (1982), Chapter 4, Units and Ephemeris, pp. 161-162, XNUMX Years of Newcome, Sun Table
- ^ Gentoshi Majima "A Study of the Calendar Law, Especially the Okiko Law"Research Bulletin, Nara Women's University Faculty of Literature, Junior and Senior High School, 2010,2011/5/20Browse.
- ^ Aoki (1982), Chapter 4, Units and Ephemeris, p.165, XNUMX Length of year Number of days in year
- ^ Aoki (1982), Chapter 2, Lunar Calendar and Solar Calendar, pp.51-53, Astronomy of the Ancient Mankind and Astronomy
- ^ Shinpei Shibata. “summer solstice". Yamagata UniversityFaculty of Science, Department of Physics. 2011/11/9Browse.
- ^ Shinpei Shibata and others "Become a starry sky guide", Technical Review
- ^ Aoki (1982), Preface Month and Hour, pp.1-2, Monthly Spectacle
- ^ a b Hiroshi Kodama. “Time units and calendar". Kobe UniversityGraduate School of Natural Science and Technology. 2011/5/20Browse.
- ^ a b c d e f g h Takuto Asako. “(PDF)". Fujimioka Junior High School/High School. 2011/5/20Browse.
- ^ Aoki (1982), Preface Month and Hour, pp.3-4, Lunar Solar Calendar
- ^ a b c Okada et al. (1994), pp.309-310, solar calendar, Egyptian calendar (Sirius calendar)
- ^ a b Okada et al. (1994), pp.310-311, solar calendar, Ethiopian calendar
- ^ a b Okada et al. (1994), p. 311, solar calendar, Persian calendar
- ^ a b c Okada et al. (1994), pp. 311-312, solar calendar, Julian calendar
- ^ Okada et al. (1994), pp.312-315, solar calendar, Gregorian calendar
- ^ Okada et al. (1994), pp.315-317, solar calendar, Mayan calendar
- ^ International Astronomical Union "SI unitsaccessed 18 February 2010. (See Table 5 and section 5.15.) Reprinted from George A. Wilkins & IAU Commission 5, "The IAU Style Manual (1989)" (PDF file) in IAU Transactions Vol. XXB
- ^ Aoki (1982), Chapter 2, Lunar Calendar and Solar Calendar, pp.97-98, Four Solar Calendars (Part 2) Julian Day
- ^ Kenjiro Miyano. “New Year Greetings". Tokyo UniversityResearch Center for Advanced Science and Technology. 2011/11/9Browse.
- ^ "[Century]", "Japanese Dictionary", Kodansha, 1989, First Printing, 1063 pages.ISBN 4-06-121057-2.
- ^ "[Half-year]", "Japanese Dictionary", Kodansha, 1989, First Printing, page 1613.ISBN 4-06-121057-2.
- ^ "[First Half]", "Japanese Dictionary", Kodansha, 1989, first edition, 388 pages.ISBN 4-06-121057-2.
- ^ "[Second half]", "Japanese Dictionary", Kodansha, 1989, 883st print, page XNUMX.ISBN 4-06-121057-2.
- ^ "[Quarter]" "Japanese dictionary" Kodansha, 1989, 872st printing, page XNUMX.ISBN 4-06-121057-2.
- ^ a b c d Sato (2009), pp.052-056, fixing the beginning of the year
- ^ Ikeuchi (1999), 3 I'm immobile like the North Star, pp.42-43, Roman calendar
- ^ Ikeuchi (1999), 3. I am immobile like the North Star, pp.44-47, history of the calendar revision
- ^ "Birth of civilization" p66-67 Toshiko Kobayashi Chuko Shinsho Published June 2015, 6
- ^ "Birth of civilization" p71-72 Toshiko Kobayashi Chuko Shinsho Published June 2015, 6
- ^ Okada et al. (1994), pp.296-298, primitive calendar
- ^ Katsuyo Okazaki"World History and Europe"KodanshaHyundai Shinsho, 2003, pages 218-219.ISBN 4-06-149687-5.
- ^ "[Great year]”. Webio English-Japanese-Japanese-English Encyclopedia /Research society, JST Science and Technology Terminology Japanese-English Bilingual Dictionary, Life Science Dictionary, Japanese WordNet, etc. 2011/5/20Browse.
- ^ Emiko Matsuyama. “Constellation of the four seasons and myths". Shutoku UniversityFaculty of Comprehensive Welfare. 2011/5/20Browse.
- ^ "[Galactic year]”. Webio English-Japanese-Japanese-English Encyclopedia /Research society, JST Science and Technology Terminology Japanese-English Bilingual Dictionary, Life Science Dictionary, Japanese WordNet, etc. 2011/5/20Browse.
- ^ a b "Science and Technology Trends March Issue Topics,  US probe to resume Mercury observations for the first time in 6 years". National Institute of Science and Technology Policy. 2011/5/20Browse.
- ^ Motomaro Shirao. “(PDF)”. Planetary geological news. 2011/5/20Browse.
- ^ "[Earth year]”. Webio English-Japanese-Japanese-English Encyclopedia /Research society, JST Science and Technology Terminology Japanese-English Bilingual Dictionary, Life Science Dictionary, Japanese WordNet, etc. 2011/5/20Browse.
- ^ "[Astronomical unit (AU)]”. Union Astronomique Internationale. 2011/10/31Browse.
- Masayuki Sato "Time in World History"Yamakawa Publishing, 2009, 1st print.ISBN +978-4-634-34966-7.
- Ryo Ikeuchi"Astronomer's magnifying glass"文藝 春秋First edition of the new book, 1999.ISBN 4-16-660060-5.
- Aoki faith"Time and calendar"Tokyo UniversityPublishing, 1982, first edition.
- Yoshiro Okada, Sueda Akune, "Modern Coyomi Reading Encyclopedia"Kashiwa Shobo, 1994, XNUMXth edition.
- Chronological Table
- List of years
- Decade - century - Millennium(Millennium)
- Age distribution
- calendar year
- new Year