BP in the UK to significantly increase profits in the first quarter to resume share buybacks
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BP has announced plans to announce its share buyback plan for the third quarter at a later date.
[London, XNUMXth Reuters] – British energy giant BP announced first-quarter earnings of $ XNUMX billion in surplus ... → Continue reading
Wikipedia related words
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Years(Thank you,British: year) IsTime OfunitIt is one of the seasons of spring, summer, autumn, winter, or rainy season and dry season... 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 365 days, but one year is 366 days.leap yearBy setting 400 times in 97 years, the average number of days per year will be 365.2425 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 1950” (1950) and “the years of” (- -Era) is also used to indicate a specific time.. 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 Western calendar and the original chronology may be written together,,News (Chinese)Take, for example,JapanThen AD2020AgainstEraUsingReiwa2 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 isGregorian calendarThen,leap yearThis is because there are 1 or 365 days in a year and the number of days (or seconds) is not stable. Furthermore, in order to synchronize 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 in a yearly cycleRice 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 a 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 thatdirection, So the vernal equinox is about 50 per year.secondEachto East MalaysiaHave moved to. this isPrecessionと 呼 ば れ る.. Therefore, the position on the earth's revolution is not constant in the solar year based on the return to the spring equinox, and the angle is about 50 seconds (revolution time about minus 20) in one year, contrary to the direction of the earth's revolution.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 a basic astronomical year isKepler'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,PerihelionThe angle shifts by about 11 seconds (revolution time of about 4 minutes) toward the orbital direction of the earth in one year. After the perihelion passage, the time until the earth comes to the next perihelion position is the "perihelion year" (average about 365.25964 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 was found from the investigation of the "day" unit density (sun-ring), that one day about 5 million years ago was short, and it is thought that one year was about 400 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..The United KingdomIt is in新石器時代Ruins ofStonehengeIs a kind of astronomical observatory and knows the time of summer solstice and winter solsticeカレンダーIt is thought that it had the function of[twenty one]
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)) From one month to 29 or 30 days, 12 times (Lunar year = about 354.36708 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 354 or 355 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 mathematicianMetonFinds that it is almost the same as 19 sun-years and 235 Shogetsu-moon, 7 degrees in the lunar year nineteenAdditional month (leap month)InsertMeton cycleInvented.. That's an average of 365.263 days a year. This cycle isBabylonia[Note 1]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SopdetAnd created a calendar system based on the summer solstice. Initially, this was a calendar system that can be called the "Least Star Calendar", where a leap month is added once every three years based on the lunar month, which is 3 days. 354 days a yearSirius calendarWas changed to.. The calendar system that has 30 times as many times 12 days as 5 times a year is ancient Ethiopia,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 IIIA leap day was added every four years during the reign, and a calendar law was established to average 1 days per year..
Republic RomeSeized the real power ofGaius Julius CaesarIntroduced the Egyptian solar calendar, which averaged 46 days in 365.25 BC[Note 2].. After his death, he was temporarily confused and operated for an average of 365.3333 days with a leap year once every three years.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 11 minutes and 14 seconds long per year, so the error from the spring equinox became noticeable. 1582,PopeGregory XIII400 times in 97 yearsleap yearTo provideGregorian calendarThe calendar was changed to 365.2425 days a year. This year’s unit was originallyCatholicIt 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 [Note 3]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.
One yearHalf6 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. In addition, divide one year into quarters of three monthsQuarterPeriod" (Quarter, English: quarter), 1st quarter, 2nd quarter, 3rd quarter, 4th quarter from the beginning of the 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 production amount ofTEvery 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 first started in 735 BC, the beginning of the year was on the first day of today's March (Martius).. laterGaius Julius Caesar(Julius Caesar)EgyptIntroduced fromsolar calendarIn 47 BC, when I switched towinter solsticeThe first day of January (Januarius), which was near the beginning of the year, was changed to the start of the year.. In Japanese, calendar month names are counted as ordinal numbers such as January and February, but Western calendar calendar month names are not. It is not always obvious which of the twelve unique names to visit, "which is the beginning of the year," and there is freedom in choosing Martius as the first calendar month or Januarius as the first calendar month (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 exampleThe United 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".Ancient greece 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 such 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.
- ^ In ancient Babylonia, it was said that six months were one year. Because of thatageWas 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）
- ^ 90 days of leap days were set up for this revision, and the year became 445 days. This year was called Anus Konfushionis (meaning "rumble years"). (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 a memoir, the official salary was able to cut off a month's salary from the monthly salary, and the aim was to save the budget that was tight at the time. (Sato (2009), pp.55-56) Also, since the Meiji 6th year of the lunar calendar was a leap year for 13 months, it only lasted for 2 days, so it was a messed up December 5th year of Meiji and the 12th year of Meiji 6Leap monthIt is also said that a total of two minutes have been floated. (Blue Bucks "Science of the Calendar" Akira Yamazaki, Yoshio Kubo (1984)) The description of the Okubo method, which was the year 6, was not the Gregorian calendar that was widespread in the West at that time, but the Julian calendar. Since it was for 1873 years (only one leap day is set every four years), the Meiji government revised the calendar again in 4, two years before the year 1, which causes a discrepancy between the two, and changed to the Gregorian calendar leap method. Revised (Bluebacks "Science of Calendar" Akira Yamazaki, Yoshio Kubo (1900)). Therefore, it was in 2 that Japan adopted the Gregorian calendar.
- ^ 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. 2011th of February 5Browse.
- ^ "【Year】”. Weblio Encyclopedia /SanseidoDaijirin. 2011th of February 5Browse.
- ^ 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. 2011th of February 5Browse.
- ^ 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. 2010th of February 11Browse.
- ^ "[Year/year]”. Etymological dictionary. 2011th of February 5Browse.
- ^ 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. 2011th of February 5Browse.
- ^ Shigeharu Takeno. “About the equinox". Niigata Institute of TechnologyDepartment of Computer Science. 2011th of February 5Browse.
- ^ a b Kazuhiro Oyamatsu. “(PDF)". Aichi Shukutoku University. 2011th of February 5Browse.
- ^ Susumu Yamaga. “Part 2-XNUMX-Science of the Universe". 2011th of February 5Browse.
- ^ a b c Takao Iijima. “(PDF)". Gakushuin University. 2011th of February 5Browse.
- ^ Koji Takahashi. “(PDF)". Saitama Institute of TechnologyFaculty of Human and Social Studies. 2011th of February 5Browse.
- ^ 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, 2010,2011th of February 5Browse.
- ^ 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. 2011th of February 11Browse.
- ^ 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. 2011th of February 5Browse.
- ^ a b c d e f g h Takuto Asako. “(PDF)". Fujimioka Junior High School/High School. 2011th of February 5Browse.
- ^ 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. 2011th of February 11Browse.
- ^ "[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. 2011th of February 5Browse.
- ^ Emiko Matsuyama. “Constellation of the four seasons and myths". Shutoku UniversityFaculty of Comprehensive Welfare. 2011th of February 5Browse.
- ^ "[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. 2011th of February 5Browse.
- ^ 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. 2011th of February 5Browse.
- ^ Motomaro Shirao. “(PDF)”. Planetary geological news. 2011th of February 5Browse.
- ^ "[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. 2011th of February 5Browse.
- ^ "[Astronomical unit (AU)]”. Union Astronomique Internationale. 2011th of February 10Browse.
This footnote indicates the "source" presented in the source/footnote.
- ^ Shinpei Shibata and others "Become a starry sky guide", Technical Review
- 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
- Year search calendar -Determining the year from the date without year display.