Japanese calendar

History

The lunisolar Chinese calendar 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 and other Asian immigrant communities.

Japan has had more than one system for designating years. including

Years

The official dating system known as nengō 年号, strictly speaking, gengō 元号, has been in use since the late 7th century. Years are numbered within eras, which are named by the reigning Emperor. 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 founded Japan – 660 BC according to the Gregorian Calendar. Usage of kōki dating can be a nationalist signal, pointing out that the history of Japan's imperial family is longer than that of Christianity, the basis of the Anno Domini (AD) system. Kōki 2600 (1940) was a special year. The 1940 Summer Olympics and Tokyo Expo were planned as anniversary events, but were canceled due to the Second Sino-Japanese War. The Japanese naval Zero Fighter 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 years 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 minus 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.

Seasons

See also "Seasonal days", below.

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 月 (-gatsu, "month"). The table below uses traditional numerals, but the use of Arabic numerals (１月, ２月, ３月 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 names (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.

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, 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 system was used for astrological purposes and little else until 1876.

The names of the days come from the five visible planets, which in turn are named after the five Chinese elements (metal, wood, water, fire, earth), and from the moon and sun (yin and yang). On the origin of the names of the days of the week, also see East Asian Seven Luminaries.

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 "half-time holiday (半ドン)". 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 "We have neither Sundays nor Saturdays!" which means "We work throughout the week."

Japanese people also use 10-day periods called Jun (旬). Each month is divided roughly into three 10-day periods. The first (from 1st to 10th) is jōjun (上旬 "upper Jun"); the second (from 11th to 20th), chūjun (中旬 "middle Jun"); the last (from 21st to 31st), gejun (下旬 "bottom Jun" ). 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."

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 (１日, ２日, ３日, etc.) is extremely common in everyday communication, almost the norm.

Tsuitachi is a worn-down form of tsuki-tachi (月立ち), 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 day of the month was also called misoka, just as the 20th day 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. The last day of the year is 大晦日 ōmisoka ("big 30th day"), 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 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 founded Japan in 660 BC.

* Part of Golden Week.

Timeline of changes to the national holidays

Gregorian months and the "One-Month Delay"

In contrast to other East Asian countries such as China, Taiwan, Vietnam, Korea and Mongolia, Japan has almost completely forgotten the Chinese calendar. 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 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. This festival is never set on February 1.

Seasonal days

Some days have special names to mark the change in seasons. The 24 Sekki (二十四節気, Nijūshi sekki) (Chinese: Jieqi) are days that divide the solar year into twenty four equal sections. Zassetsu (雑節) is a collective term for the seasonal days other than the 24 Sekki. 72 Kō (七十二候, Shichijūni kō) 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.

24 Sekki

Days can vary by ±1 day.

Zassetsu

Shanichi days can vary by as much as ±5 days. Chūgen has a fixed day. All other days can vary by ±1 day.

Many zassetsu days occur in multiple seasons:

Seasonal festivals

The following are known as the five seasonal festivals (節句 sekku, also 五節句 gosekku). The Sekku were made official holidays during Edo era on Chinese lunisolar calendar. The dates of these festivals are confused nowadays. Some on the Gregorian calendar, others on "Tsuki-okure".

1. 7th day of the 1st Month: 人日 (Jinjitsu), 七草の節句 (Nanakusa no sekku) held on 7 January
2. 3rd day of the 3rd Month: 上巳 (Jōshi), 桃の節句 (Momo no sekku) held on 3 March in many areas, but in some area on 3 April 雛祭り (Hina matsuri), Girls' Day.
3. 5th day of the 5th Month: Tango (端午): mostly held on 5 May
4. 端午の節句 (Tango no sekku), 菖蒲の節句 (Ayame no sekku)
5. Boys' Day. Overlaps with the national holiday Children's Day.
6. 7th day of the 7th Month: 七夕 (Shichiseki, Tanabata), 星祭り (Hoshi matsuri ) held on 7 July in many areas, but in northern Japan held on 7 August (e.g. in Sendai)
7. 9th day of the 9th Month: 重陽 (Chōyō), 菊の節句 (Kiku no sekku) almost out of vogue today

Not Sekku:

Rokuyō

The rokuyō (六曜) are a series of six days calculated from the date of Chinese calendar 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 rokki (六輝). In order, they are:

The rokuyō days are easily calculated from the Japanese Lunisolar calendar. Lunisolar January 1 is always senshō, with the days following in the order given above until the end of the month. Thus, January 2 is tomobiki, January 3 is senbu, and so on. Lunisolar February 1 restarts the sequence at tomobiki. Lunisolar March 1 restarts at senbu, and so on for each month. The last six months repeat the patterns of the first six, so July 1 = senshō, December 1 is shakkō and the moon-viewing day of August 15 is always a "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.