Koinobori, flags decorated like koi, are popular decorations around Children's Day

This mural on the wall of Shin-Ochanomizu subway station in Tokyo celebrates Hazuki, the eighth month.

On January 1, 1873, Japan adopted the Gregorian calendar. Before 1873, the Chinese style lunisolar calendar had been in use since 7th century.^[1] Japanese eras are still in use.

Official calendar[link]

Japan has refused to accept some elements of the Gregorian calendar itself. The present Japanese Solar calendar does not include following events:

• March 21 as the fixed Vernal Equinox Day
• The leap year calculating system based on Anno Domini

The Northward equinox is a national holiday in Japan and an important religious holiday in both Japanese Buddhism and Shinto but is determined completely using astronomy. The date is not fixed but is announced by National Astronomical Observatory of Japan every year.

Sunday and Saturday are regarded as "Western style take-a-rest days". 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 Japanese imperial navy song says "We have neither Sundays nor Saturdays!" which means "We work throughout the week."

Leap years in the Japanese solar calendar have been legally determined based on kōki since 1899,^[2] however this law sets the number "kōki-660" to be the base of calculation, so leap years in Japanese solar calendar are aligned with that of the Gregorian calendar.

Years[link]

Since the adoption of the Gregorian calendar, three different systems for counting years have been used in Japan:

• The imperial year (皇紀, kōki^?) based on the mythical founding of Japan by Emperor Jimmu in 660 BC.
• The Japanese era name (年号, nengō^?) based on the reign of the current emperor, the year 2012 being Heisei 24
• The European Common Era (Anno Domini) (西暦, seireki^?) designation

Of these three, the last two are still in current use.

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. In terms of nationalism, kōki emphasizes the long history of Japan and the imperial family because it is a larger number than the Anno Domini year (AD). 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 aircraft 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.

Months[link]

Common names[link]

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"):

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 names of the months are as follows:

• 1st month: mutsuki (睦月^?, "Month of Affection")^[3]
• 2nd month: kisaragi (如月^?) or kinusaragi (衣更着^?, "Changing Clothes")^[3]
• 3rd month: yayoi (弥生^?, "New Life")^[3]
• 4th month: uzuki (卯月^?, "u-no-hana month")^[3] The u-no-hana (卯の花) is a flower, of the genus Deutzia.^[4]
• 5th month: satsuki (皐月^?) or sanaetsuki (早苗月^?, "Early-rice-planting Month")^[3]
• 6th month: minatsuki (水無月^?, "Month of Water"). The 無 character, which normally means "absent" or "there is no", is here ateji, that is, used only for the sound "na". In this name the na is actually a possessive particle, so Minazuki means "month of water", not "month without water", and this is in reference to the flooding of the rice fields, which require large quantities of water.^[5]
• 7th month: fumizuki (文月^?, "Month of Books")^[3]
• 8th month: hazuki (葉月^?, "Month of Leaves"). In old Japanese, the month was called 葉落ち月 (haochizuki, or Month of Falling Leaves).^[3]
• 9th month: nagatsuki (長月^?, "The Long Month")^[3]
• 10th month: 神無月 (kaminazuki or kannazuki, "month of the gods "). The 無 character, which normally means "absent" or "there is not", was here probably originally used as ateji, that is used only for the sound "na". In this name the na is actually a possessive particle, so kaminazuki means "month of the gods", not "month without gods" ("kaminakizuki"), similarly to minatsuki, the "month of water".^[6] However, by false etymology this became commonly interpreted to mean that because in that month all the Shinto kami gather at Izumo Shrine shrine in Izumo province (modern-day Shimane Prefecture), there are no gods in the rest of the country. Thus in Izumo Province, the month is called kamiarizuki (神有月 or 神在月^?, "month with gods"). This interpretation is the one commonly cited in western works.^[7] Various other etymologies have also been suggested from time to time.^[8]
• 11th month: shimotsuki (霜月^?, "Month of Frost")^[3]
• 12th month: shiwasu (師走^?, "Priests Running"). This is in reference to priests being busy at the end of the year for New Year's preparations and blessings.^[3]

Note:' 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 it is not entirely accurate to equate the first month with January.

Subdivisions of the month[link]

Japan uses a seven-day week, aligned with the Western calendar. The seven day week, with names for the days corresponding directly to those used in Europe, was brought to Japan around AD 800 with Buddhism calendar. The system was used for astrological purposes and little else until 1876. Since 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 Christianity, Judaism or Islam). The names come from the five visible planets, which in turn are named after the five Chinese elements (gold, 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.

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 day) 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[link]

Each day of the month has a semi-systematic but irregularly formed name:

(Note that using Arabic numerals, as 14日, 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 classic word comes from the tradition of lunisolar calendar. The 30th day of the month was also called "misoka" just as 20th day 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 (the big 30th day), and that term is still in use.

There is a tradition to use a term kichijitsu (good day) for ceremonial events such as the preparation day of a wedding invitation letter and the build day of a memorial stone tablet. It is, however, not recognized as a legally valid date indication. So, for example, a will with kichijitsu as its preparation date is not legally valid.^{[clarification needed]}

National holidays[link]

After WW2, names of Japanese national holidays were completely changed because of the secular state principle (Article 20, The Constitution of Japan). Although many of them are actually originated from Shinto, Buddhism and some important events of Japanese imperial family, it is not easy to understand the original meaning from its superficial and vague official name.

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[link]

• 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 Emperor Showa died on January 7, the Emperor's Birthday became December 23 and Greenery Day took place of the former Emperor's birthday.
• 2000, 2003: Happy Monday System (ハッピーマンデー制度, Happī Mandē Seido^?) 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 generic national holiday (国民の休日, kokumin no kyūjitsu^?) that existed after 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.

Customary issues in modern Japan[link]

Gregorian months and the "One Month Delay"[link]

Clearly 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 is officially regarded as the "first month" even when setting the date of every Japanese traditional folklore event (other months are the same: February as the second month, March as the third, and so on). But this system often brings strong seasonal sense of gap. The modern Japanese culture invented a kind of "compromised" calendar. This calendar, which is called "Tsuki-okure (One Month Delay)" or "Chūreki(The Eclectic Calendar"), regards February as "1st Month". 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[link]

Some days have special names to mark the change in seasons. The 24 Sekki (二十四節気, Nijūshi sekki^?) 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[link]

• Risshun (立春^?): February 4—Beginning of spring
• Usui (雨水^?): February 19—Rain water
• Keichitsu (啓蟄^?): March 5—awakening of hibernated (insects)
• Shunbun (春分^?): March 20—Vernal equinox, middle of spring
• Seimei (清明^?): April 5—Clear and bright
• Kokuu (穀雨^?): April 20—Grain rain
• Rikka (立夏^?): May 5—Beginning of summer
• Shōman (小満^?): May 21—Grain full
• Bōshu (芒種^?): June 6—Grain in ear
• Geshi (夏至^?): June 21—Summer solstice, middle of summer
• Shōsho (小暑^?): July 7—Small heat
• Taisho (大暑^?): July 23—Large heat
• Risshū (立秋^?): August 7—Beginning of autumn
• Shosho (処暑^?): August 23—Limit of heat
• Hakuro (白露^?): September 7—White dew
• Shūbun (秋分^?): September 23—Autumnal equinox, middle of autumn
• Kanro (寒露^?): October 8—Cold dew
• Sōkō (霜降^?): October 23—Frost descent
• Rittō (立冬^?): November 7—Beginning of winter
• Shōsetsu (小雪^?): November 22—Small snow
• Taisetsu (大雪^?): December 7—Large snow
• Tōji (冬至^?): December 22—Winter solstice, middle of winter
• Shōkan (小寒^?): January 5 Small Cold—a.k.a. 寒の入り (Kan no iri) entrance of the cold
• Daikan (大寒^?): January 20—Major cold

Days can vary by ±1 day. See also: Jieqi.

Zassetsu[link]

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

Many zassetsu days occur on multiple seasons:

• Setsubun (節分^?) refers to the day before each season, or the eves of Risshun, Rikka, Rishū, and Rittō; especially the eve of Risshun.

• Doyō (土用^?) refers to the 18 days before each season, especially the one before fall which is known as the hottest period of a year.

• Higan (彼岸^?) is the seven middle days of spring and autumn, with Shunbun at the middle of the seven days for spring, Shūbun for fall.

• Shanichi (社日^?) is the Tsuchinoe (戊^?) day closest to Shunbun (middle of spring) or Shūbun (middle of fall), which can be as much as -5 to +4 days away from Shunbun/Shūbun.

Seasonal festivals[link]

The following are known as the five seasonal festivals (節句 sekku, also 五節句 go sekku). 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 today
2. 3rd day of the 3rd Month: 上巳 (Jōshi), 桃の節句 (Momo no sekku) held on 3 March in many area, 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
   • 端午の節句 (Tango no sekku), 菖蒲の節句 (Ayame no sekku)
   • Boys' Day. Overlaps with the national holiday Children's Day.
4. 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)
5. 9th day of the 9th Month: 重陽 (Chōyō), 菊の節句 (Kiku no sekku) almost out of vogue today

Not Sekku:

• January 1: Japanese New Year
• August 15: Obon - 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

[edit] 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 15th" is always a "butsumetsu."

This system did not become popular in Japan until the end of the Edo period.

April 1[link]

The first day of April has broad significance in Japan. It marks the beginning of the government's fiscal year.^[9] 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. (For more see also academic term.)

See also[link]

• East Asian age reckoning
• Jikkan Jūnishi
• List of kigo

References[link]

External links[link]

• Japanese calendar tables and zodiac signs, in Kanji, Hiragana, Romaji, and English,
• Japanese calendar history by the National Diet Library
• The Lunar Calendar in Japan
• The Japanese Lunar Calendar Mechanics of the Japanese lunar calendar and hints on using NengoCalc (see below)
• Koyomi no page in Japanese
• Koyomi no hanashi in Japanese
• Rokuyō calculator in Japanese
• Rokuyō calendar 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
• NengoCalc (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)