Japanese calendar types have included a range of official and unofficial systems. At present, Japan uses the Gregorian calendar together with year designations stating the year of the reign of the current Emperor. The written form starts with the year, then the month and finally the day, coinciding with the ISO 8601 standard. For example, February 16, 2003 can be written as either 2003年2月16日 or 平成15年2月16日 (the latter following the regnal year system). 年 reads ''nen'' and means "year", 月 reads ''gatsu'' or 「がつ」and means "month" and finally 日 (usually) reads ''nichi'' (its pronunciation depends on the number that precedes it, see below) and means "day". Prior to the introduction of the Gregorian calendar in 1873, the reference calendar was based on the lunisolar

Chinese calendar The traditional Chinese calendar (also known as the Agricultural Calendar ��曆; 农历; ''Nónglì''; 'farming calendar' Former Calendar ��曆; 旧历; ''Jiùlì'' Traditional Calendar ��曆; 老历; ''Lǎolì'', is a lunisolar calendar ...

History

The lunisolar

was introduced to Japan via Korea in the middle of the sixth century. After that, Japan calculated its calendar using various Chinese calendar procedures, and from 1685, using Japanese variations of the Chinese procedures. But in 1873, as part of Japan's Meiji period modernization, a calendar based on the solar Gregorian calendar was introduced. In Japan today, the old Chinese calendar is virtually ignored; celebrations of the Lunar New Year are thus limited to

Chinese Chinese can refer to: * Something related to China * Chinese people, people of Chinese nationality, citizenship, and/or ethnicity **''Zhonghua minzu'', the supra-ethnic concept of the Chinese nation ** List of ethnic groups in China, people of v ...

and other Asian immigrant communities. Japan has had more than one system for designating years: * The Chinese sexagenary cycle was introduced early into Japan. It was often used together with era names, as in the 1729 Ise calendar shown above, which is for "the 14th year of Kyōhō, tsuchi-no-to no tori", i.e., . Now, though, the cycle is seldom used except around New Year. * The system was also introduced from China, and has been in continuous use since AD 701. Since the Taishō Emperor's ascension in 1912, each emperor's reign has begun a new era; before 1868 era names were often also declared for other reasons. Nengō are the official means of dating years in Japan, and virtually all government business is conducted using that system. It is also in general use in private and personal business. * The is based on the date of the legendary founding of Japan by

Emperor Jimmu was the legendary first emperor of Japan according to the '' Nihon Shoki'' and '' Kojiki''. His ascension is traditionally dated as 660 BC.Kelly, Charles F"Kofun Culture"Meiji period. Nowadays, Japanese people know it as well as the regnal eras. File:Briefly_Abridged_Calendar_of_1873%2C_Hiroshige_Museum_of_Art.JPG, Briefly Abridged Calendar of 1873 File:Calendar_for_1907%2C_Nakai_Tokujiro_%28Pub.%29%2C_Hiroshige_Museum_of_Art.JPG, Calendar for 1907

Official calendar

Years

The official dating system known as (or, strictly speaking, ), has been in use since the late 7th century. Years are numbered within regnal eras, which are named by the reigning

Emperor An emperor (from la, imperator, via fro, empereor) is a monarch, and usually the sovereign ruler of an empire or another type of imperial realm. Empress, the female equivalent, may indicate an emperor's wife ( empress consort), mother (emp ...

. Beginning with Meiji (1868–1912), each reign has been one era, but many earlier Emperors decreed a new era upon any major event; the last pre-Meiji Emperor's reign (1846–1867) was split into seven eras, one of which lasted only one year. The ''nengō'' system remains in wide use, especially on official documents and government forms. The imperial year system (''kōki'') was used from 1872 to the Second World War. Imperial year 1 (''Kōki'' 1) was the year when the legendary

Emperor Jimmu was the legendary first emperor of Japan according to the '' Nihon Shoki'' and '' Kojiki''. His ascension is traditionally dated as 660 BC.Kelly, Charles F"Kofun Culture"nationalist Nationalism is an idea and movement that holds that the nation should be congruent with the State (polity), state. As a movement, nationalism tends to promote the interests of a particular nation (as in a in-group and out-group, group of peo ...

signal, pointing out that the history of Japan's imperial family is longer than that of Christianity, the basis of the

Anno Domini The terms (AD) and before Christ (BC) are used to label or number years in the Julian and Gregorian calendars. The term is Medieval Latin and means 'in the year of the Lord', but is often presented using "our Lord" instead of "the Lord", ...

(AD) system. ''Kōki'' 2600 (1940) was a special year. The

1940 Summer Olympics The 1940 Summer Olympics, officially known as the Games of the XII Olympiad, were originally scheduled to be held from September 21 to October 6, 1940, in Tokyo City, Empire of Japan. They were rescheduled for Helsinki, Finland, to be held from ...

and Tokyo Expo were planned as anniversary events, but were canceled due to the Second Sino-Japanese War. The Japanese naval

Zero Fighter The Mitsubishi A6M "Zero" is a long-range carrier-based fighter aircraft formerly manufactured by Mitsubishi Aircraft Company, a part of Mitsubishi Heavy Industries, and was operated by the Imperial Japanese Navy from 1940 to 1945. The A6M was ...

was named after this year. After the Second World War, the United States occupied Japan, and stopped the use of ''kōki'' by officials. Today, ''kōki'' is rarely used, except in some judicial contexts. The 1898 law determining the placement of

leap year A leap year (also known as an intercalary year or bissextile year) is a calendar year that contains an additional day (or, in the case of a lunisolar calendar, a month) added to keep the calendar year synchronized with the astronomical year o ...

s is officially based on the ''kōki'' years, using a formula that is effectively equivalent to that of the Gregorian calendar: if the ''kōki'' year number is evenly divisible by four, it is a leap year, unless the number minus 660 is evenly divisible by 100 and not by 400. Thus, for example, the year ''Kōki'' 2560 (AD 1900) is divisible by 4; but 2560 − 660 = 1900, which is evenly divisible by 100 and not by 400, so ''kōki'' 2560 was not a leap year, just as in most of the rest of the world. The present era,

Reiwa is the current era of Japan's official calendar. It began on 1 May 2019, the day on which Emperor Akihito's elder son, Naruhito, ascended the throne as the 126th Emperor of Japan. The day before, Emperor Akihito abdicated the Chrysanthemu ...

, formally began on 1 May 2019. The name of the new era was announced by the Japanese government on 1 April 2019, a month prior to Naruhito's succession to the throne. The previous era, Heisei, came to an end on 30 April 2019, after Japan's former emperor,

Akihito is a member of the Imperial House of Japan who reigned as the 125th emperor of Japan from 7 January 1989 until his abdication on 30 April 2019. He presided over the Heisei era, ''Heisei'' being an expression of achieving peace worldwide. Bor ...

, abdicated the throne. Reiwa is the first era name whose characters come from a Japanese root source; prior eras' names were taken from Chinese classic literature.

Seasons

Months

The modern Japanese names for the months literally translate to "first month", "second month", and so on. The corresponding number is combined with the suffix (''-gatsu'', "month"). The table below uses traditional numerals, but the use of Western numerals (, , etc.) is common. In addition, every month has a traditional name, still used by some in fields such as poetry; of the twelve, ''Shiwasu'' is still widely used today. The opening paragraph of a letter or the greeting in a speech might borrow one of these names to convey a sense of the season. Some, such as '' Yayoi'' and '' Satsuki'', do double duty as

given name A given name (also known as a forename or first name) is the part of a personal name quoted in that identifies a person, potentially with a middle name as well, and differentiates that person from the other members of a group (typically a fa ...

s (for women). These month names also appear from time to time on '' jidaigeki'', contemporary television shows and movies set in the Edo period or earlier. Japanese calendar december

The old Japanese calendar was an adjusted lunar calendar based on the Chinese calendar, and the year—and with it the months—started anywhere from about 3 to 7 weeks later than the modern year, so in historical contexts it is not entirely accurate to equate the first month with January.

Subdivisions of the month

Japan uses a

seven-day week A week is a unit of time equal to seven days. It is the standard time period used for short cycles of days in most parts of the world. The days are often used to indicate common work days and rest days, as well as days of worship. Weeks are ofte ...

, aligned with the Western calendar. The seven-day week, with names for the days corresponding to the Latin system, was brought to Japan around AD 800 with the

Buddhist calendar The Buddhist calendar is a set of lunisolar calendars primarily used in Cambodia, Laos, Myanmar, India, Sri Lanka, and Thailand as well as in Malaysia, Singapore and Vietnam by Chinese populations for religious or official occasions. W ...

. The system was used for astrological purposes and little else until 1876. Much like in multiple European languages, in which the names for weekdays are, partially or fully, based on what the Ancient Romans considered the seven visible planets, meaning the five visible planets and the sun and the moon, in The Far East the five visible planets are named after the five Chinese elements (metal, wood, water, fire, earth.) On the origin of the names of the days of the week, also see East Asian Seven Luminaries. * For those wondering, the Sun is 太陽 (great yang) and the Moon is 太陰 (great yin) Taijitu - Small (CW)

Sunday and Saturday are regarded as "Western style take-a-rest days". Since the late 19th century, Sunday has been regarded as a "full-time holiday", and Saturday a . These holidays have no religious meaning (except those who believe in Christianity or Judaism). Many Japanese retailers do not close on Saturdays or Sundays, because many office workers and their families are expected to visit the shops during the weekend. An old Imperial Japanese Navy song () says "Mon Mon Tue Wed Thu Fri Fri!" which means "We work throughout the entire week." Japanese people also use 10-day periods called . Each month is divided into two 10-day periods and a third with the remaining 8 to 11 days: * The first (from the 1st to the 10th) is * The second (from the 11th to the 20th), * The last (from the 21st to the end of the month), . These are frequently used to indicate approximate times, for example, "the temperatures are typical of the ''jōjun'' of April"; "a vote on a bill is expected during the ''gejun'' of this month." The magazine '' Kinema Junpo'' was originally published once every ''jun'' (i.e. three times a month).

Days of the month

Each day of the month has a semi-systematic name. The days generally use ''kun'' (native Japanese) numeral readings up to ten, and thereafter ''on'' (Chinese-derived) readings, but there are some irregularities. The table below shows dates written with traditional numerals, but use of Arabic numerals (, , , etc.) is extremely common in everyday communication, almost the norm. ''Tsuitachi'' is a worn-down form of ''tsuki-tachi'' (), which means "the month beginning". The last day of the month was called ''tsugomori'', which means "Moon hidden". This classical word comes from the tradition of the lunisolar calendar. The 30th was also called ''misoka'', just as the 20th is called ''hatsuka''. Nowadays, the terms for the numbers 28–31 plus ''nichi'' are much more common. However, ''misoka'' is much used in contracts, etc., specifying that a payment should be made on or by the last day of the month, whatever the number is.

New Year's Eve In the Gregorian calendar, New Year's Eve, also known as Old Year's Day or Saint Sylvester's Day in many countries, is the evening or the entire day of the December 31, last day of the year, on 31 December. The last day of the year is commonly ...

is known as , and that term is still in use. There is traditional belief that some days are lucky (''kichijitsu'') or unlucky. For example, there are some who will avoid beginning something on an unlucky day.

National holidays

After World War II, the names of Japanese national holidays were completely changed because of the secular state principle (Article 20, The Constitution of Japan). Although many of them actually originated from Shinto,

Buddhism Buddhism ( , ), also known as Buddha Dharma and Dharmavinaya (), is an Indian religion or philosophical tradition based on teachings attributed to the Buddha. It originated in northern India as a -movement in the 5th century BCE, and gra ...

and important events relating to the Japanese imperial family, it is not easy to understand the original meanings from the superficial and vague official names. Notes: Single days between two national holidays are taken as a bank holiday. This applies to May 4, which is a holiday each year. When a national holiday falls on a Sunday the next day that is not a holiday (usually a Monday) is taken as a holiday. ::^† Traditional date on which according to legend

Emperor Jimmu was the legendary first emperor of Japan according to the '' Nihon Shoki'' and '' Kojiki''. His ascension is traditionally dated as 660 BC.Kelly, Charles F"Kofun Culture"Golden Week.

Timeline of changes to national holidays

* 1948: The following national holidays were introduced: New Year's Day, Coming-of-Age Day, Constitution Memorial Day, Children's Day, Autumnal Equinox Day, Culture Day, Labour Thanksgiving Day. * 1966: Health and Sports Day was introduced in memory of the 1964 Tokyo Olympics. Vernal Equinox Day was also introduced. * 1985: Reform to the national holiday law made May 4, sandwiched between two other national holidays, also a holiday. * 1989: After the

Shōwa Emperor Emperor , commonly known in English-speaking countries by his personal name , was the 124th emperor of Japan, ruling from 25 December 1926 until his death in 1989. Hirohito and his wife, Empress Kōjun, had two sons and five daughters; he was ...

died on January 7, the Emperor's Birthday became December 23 and Greenery Day took the place of the former Emperor's birthday. * 2000, 2003: moved several holidays to Monday. Starting with 2000: Coming-of-Age Day (formerly January 15) and Health and Sports Day (formerly October 10). Starting with 2003: Marine Day (formerly July 20) and Respect for the Aged Day (formerly September 15). * 2005, 2007: According to a May 2005 decision, starting with 2007 Greenery Day will be moved from April 29 to May 4 replacing a that existed after the 1985 reform, while April 29 will be known as Shōwa Day. * 2009: September 22 may become sandwiched between two holidays, which would make this day a national holiday. * 2014: Mountain Day established as a new holiday, to be observed starting 2016 * 2019: Emperor's Birthday not celebrated. The final celebration of Emperor's Birthday during the Heisei era took place on December 23, 2018, the birthday of

. After the start of the Reiwa era on 1 May 2019, the next celebration of Emperor's Birthday is expected to take place on or around 23 February 2020, the birthday of the reigning Emperor Naruhito (as Naruhito's birthday falls on a Sunday in 2020, the official public holiday is expected to be celebrated on Monday, 24 February 2020 instead).

Customary issues in modern Japan

Gregorian months and the "One-Month Delay"

In contrast to other East Asian countries such as China, Vietnam, Korea and Mongolia, Japan has almost completely forgotten the

. Since 1876, January has been officially regarded as the "first month" even when setting the date of Japanese traditional folklore events (other months are the same: February as the second month, March as the third, and so on). But this system often brings a strong seasonal sense of gap since the event is 3 to 7 weeks earlier than in the traditional calendar. Modern Japanese culture has invented a kind of "compromised" way of setting dates for festivals called ''Tsuki-okure'' ("One-Month Delay") or ''Chūreki'' ("The Eclectic Calendar"). The festival is celebrated just one solar calendar month later than the date on the Gregorian calendar. For example, the Buddhist festival of

Obon or just is fusion of the ancient Japanese belief in ancestral spirits and a Japanese Buddhist custom to honor the spirits of one's ancestors. This Buddhist–Confucian custom has evolved into a family reunion holiday during which people retu ...

was the 15th day of the 7th month. Many places the religious services are held on July 15. However, in some areas, the rites are normally held on August 15, which is more seasonally close to the old calendar. (The general term "Obon holiday" always refers to the middle of August.) Although this is just de facto and customary, it is broadly used when setting the dates of many folklore events and religious festivals. But Japanese New Year is the great exception. The date of Japanese New Year is always January 1.

Seasonal days

Some days have special names to mark the change in seasons. The 24 ''sekki'' () are days that divide the solar year into twenty four equal sections. is a collective term for the seasonal days other than the 24 ''sekki''. days are made from dividing the 24 ''sekki'' of a year further by three. These were named based upon the climate of Northern China, so many of the names do not fit in with the climate of Japanese archipelago. But some of these names, such as ''Shunbun'', ''Risshū'' and ''Tōji'', are still used quite frequently in everyday life in Japan.

The 24 sekki

Dates can vary by one day either way. * : February 4—Beginning of spring * : February 19—Rain water * : March 5—Awakening of hibernated (insects) * : March 20— Vernal equinox, middle of spring * : April 5—Clear and bright * : April 20—Grain rain * : May 5—Beginning of summer * : May 21—Grain full * : June 6—Grain in ear * : June 21—

Summer solstice The summer solstice, also called the estival solstice or midsummer, occurs when one of Earth's poles has its maximum tilt toward the Sun. It happens twice yearly, once in each hemisphere ( Northern and Southern). For that hemisphere, the summer s ...

, middle of summer * : July 7—Small heat * : July 23—Large heat * : August 7—Beginning of autumn * : August 23—Limit of heat * : September 7—White dew * : September 23— Autumnal equinox, middle of autumn * : October 8—Cold dew * : October 23—Frost descent * : November 7—Beginning of winter * : November 22—Small snow * : December 7—Large snow * : December 22— Winter solstice, middle of winter * : January 5—Small Cold; or —Entrance of the cold * : January 20—Major cold

''Zassetsu''

''Shanichi'' dates can vary by as much as 5 days. ''Chūgen'' has a fixed day. All other days can vary by one day. Many ''zassetsu'' days occur in multiple seasons: * refers to the day before each season, or the eves of ''Risshun'', ''Rikka'', ''Rishū'', and ''Rittō''; especially the eve of ''Risshun''. * refers to the 18 days before each season, especially the one before fall which is known as the hottest period of a year. * is the seven middle days of spring and autumn, with ''Shunbun'' at the middle of the seven days for spring, ''Shūbun'' for fall. * is the day closest to ''Shunbun'' (middle of spring) or ''Shūbun'' (middle of fall), which can be as much as 5 days before to 4 days after ''Shunbun''/''Shūbun''.

Seasonal festivals

The following are known as the five seasonal festivals ( ''sekku'', also '' gosekku''). The ''sekku'' were made official holidays during Edo period on Chinese lunisolar calendar. The dates of these festivals are confused nowadays; some on the Gregorian calendar, others on "''Tsuki-okure''". # 7th day of the 1st month: (''Jinjitsu''), (''

Nanakusa no sekku The Festival of Seven Herbs or ''Nanakusa no sekku'' ( ja, ) is the long-standing Japanese custom of eating seven-herb rice porridge (七草粥, ''nanakusa-gayu'', lit. "7 Herbs Rice-Congee") on January 7 (''Jinjitsu''); one of the '' Gosekk ...

'') held on 7 January # 3rd day of the 3rd month: (''Jōshi''), (''Momo no sekku'') held on 3 March in many areas, but in some area on 3 April #* (''

Hina matsuri , also called Doll's Day or Girls' Day, is a religious (Shinto) holiday in Japan, celebrated on 3March of each year. Nussbaum, Louis-Frédéric (2005)"Hina Matsuri"in ''Japan Encyclopedia'', p. 313. Platforms covered with a red carpet–mater ...

''), Girls' Day. # 5th day of the 5th month: Tango (): mostly held on 5 May #* (''

Tango no sekku , also known as , is one of the five annual ceremonies that were traditionally held at the Japanese imperial court called . It is the Japanese equivalent of Double Fifth and was celebrated on the fifth day of the fifth moon in the lunar calendar o ...

''), ('' Ayame no sekku'') #* Boys' Day. Overlaps with the national holiday Children's Day. # 7th day of the 7th month: (''Shichiseki'', '' Tanabata''), ('' Hoshi matsuri '') held on 7 July in many areas, but in northern Japan held on 7 August (e.g. in Sendai) # 9th day of the 9th month: (''Chōyō''), ('' Kiku no sekku'') almost out of vogue today Not ''sekku'': * January 1: Japanese New Year * August 15:

– the date is "''Tsuki-okure''". In central Tokyo Obon is held on July 15 (The local culture of Tokyo tends to dislike Tsuki-okure custom.) * December 31:

Ōmisoka —or —is a Japanese traditional celebration on the last day of the year. Traditionally, it was held on the final day of the 12th lunar month. With Japan's switch to using the Gregorian calendar at the beginning of the Meiji era, December 31 ( ...

''Rokuyō''

The are a series of six days calculated from the date of

that supposedly predict whether there will be good or bad fortune during that day. The ''rokuyō'' are commonly found on Japanese calendars and are often used to plan weddings and funerals, though most people ignore them in ordinary life. The ''rokuyō'' are also known as the . In order, they are: The ''rokuyō'' days are easily calculated from the Japanese lunisolar calendar. The first day of the first month is always ''senshō'', with the days following in the order given above until the end of the month. Thus, the 2nd day is ''tomobiki'', the 3rd is ''senbu'', and so on. The 1st day of the 2nd month restarts the sequence at ''tomobiki''. The 3rd month restarts at ''senbu'', and so on for each month. The latter six months repeat the patterns of the first six, so the 1st of the 7th is ''senshō'', the 1st of the 12th is ''shakkō'' and the moon-viewing day on the 15th of the 8th is always ''butsumetsu''. This system did not become popular in Japan until the end of the Edo period.

April 1

The first day of April has broad significance in Japan. It marks the beginning of the government's fiscal year. Many corporations follow suit. In addition, corporations often form or merge on that date. In recent years, municipalities have preferred it for mergers. On this date, many new employees begin their jobs, and it is the start of many real-estate leases. The school year begins on April 1.

References

External links

Rokuyo – Lucky and Unlucky Days of the Japanese Calendar
in Japanese * National Diet Library
"The Japanese Calendar"The Japanese Lunar Calendar
Mechanics of the Japanese lunar calendar and hints on using NengoCalc (see below)

in Japanese
Koyomi no hanashi
in Japanese
Rokuyō calculator
in Japanese

in English
Convert Western Years to Japanese Years
converts Gregorian calendar years to Japanese Emperor Era years (known as nengo)
Japanese Year Dates
Detailed explanations of Reign years, Era years, Cyclic years, Western years, Imperial years

(Tool for converting Japanese dates into Western equivalents)
This Year in Japan
Shows what the current year in Japan is
Convert a Western year into a Japanese year
(sci.lang.Japan FAQ pages) {{DEFAULTSORT:Japanese Calendar * Modified Gregorian calendars Specific calendars 1873 disestablishments in Japan