Japanese calendar facts for kids

1729 calendar, which used the Jōkyō calendar procedure, published by Ise Grand Shrine

The Japanese calendar helps people in Japan keep track of time. Today, Japan uses the same calendar as most of the world, called the Gregorian calendar. But they also add the name of the current Emperor's reign to the year. This is called the era name system.

When writing dates in Japan, they usually start with the year, then the month, and finally the day. This is similar to the ISO 8601 standard. For example, February 16, 2003, can be written as 2003年2月16日. Or, using the Emperor's reign year, it would be 平成15年2月16日. The Japanese word 年 (read nen) means "year," 月 (read gatsu) means "month," and 日 (read nichi or other ways depending on the number) means "day."

Before 1873, Japan used a calendar based on the lunisolar Chinese calendar. This older system followed both the sun and the moon.

History of Japanese Calendars

A Japanese Calendar from 1867, made using a woodcut technique.

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  Briefly Abridged Calendar of 1873

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  Calendar for 1907

Over many centuries, Japan has used different ways to name years. The two main systems used today are the era name system (元号 (gengō)) and the Western calendar system (西暦 (seireki)).

The Old Chinese Calendar System

The lunisolar Chinese calendar arrived in Japan around the mid-6th century. Japan then used different ways to calculate its calendar, often based on Chinese methods. From 1685, Japan developed its own versions of these Chinese methods.

Even though the old Chinese calendar is not used for daily dates anymore, its influence can still be seen. For example, the idea of "lucky and unlucky days" (which we'll talk about later) and the traditional names for each month come from this old system.

Era Names (Gengō)

The era name system, called 元号 (gengō), also came from China. It has been used continuously in Japan since the year 701 AD. When a new Emperor begins their rule, a new era name is chosen. Before 1868, emperors could have several era names during their reign, often to mark important events. For example, Emperor Kōmei (who ruled from 1846 to 1867) had seven different era names!

However, starting with Emperor Meiji in 1868, each Emperor has only one era name for their entire reign. This makes it simpler. The gengō system is still very important in Japan, especially for official papers and government forms. Many people also use it in their daily lives.

The current era is called Reiwa. It officially began on May 1, 2019. This was when Naruhito became the new Emperor. The name "Reiwa" was announced by the Japanese government on April 1, 2019. The era before Reiwa was Heisei, which ended on April 30, 2019, when the previous Emperor, Akihito, stepped down. Interestingly, Reiwa is the first era name that comes from Japanese writings, while older era names came from Chinese classic literature.

Japanese Imperial Years (Kōki or Kigen)

The Japanese imperial year system, known as 皇紀 (kōki) or 紀元 (kigen), counts years from the legendary founding of Japan by Emperor Jimmu in 660 BC. So, 660 BC is considered Kōki 1. This system was first used in official calendars in 1873.

For example, Kōki 2600 was the year 1940. Special events were planned for this year, but they were canceled. After World War II, the use of kōki by officials was stopped. Today, kōki is rarely used, except in some legal situations.

The Gregorian Calendar (Seireki)

The Western calendar system, called 西暦 (seireki), is the same solar Gregorian calendar used in many countries. It was first brought to Japan in 1873 as part of Japan's efforts to modernize during the Meiji period.

Today, most Japanese people know and use the Gregorian calendar alongside the era name system.

How Time is Divided

Seasons in Japan

Japan has four main seasons, just like many Western countries:

Japan also has a traditional system of 72 microseasons (候, kō). These are very small periods of about five days each, and they describe subtle changes in nature and the weather throughout the year. This system was adapted from China in 1685. Each microseason has its own traditional customs, plants, and animals associated with it.

For example, in early spring, you might hear about "the east wind melting the thick ice" or "bush warblers singing in the countryside." In summer, you might see "frogs beginning croaking" or "lotuses beginning to bloom." Autumn brings "cool winds" and "thick fog," while winter has "the land beginning to freeze" and "hens beginning to lay eggs."

Special Seasonal Days (Zassetsu)

Zassetsu (雑節) is a name for special seasonal days that fall within the 72 microseasons. These days often mark important changes in the year.

For example, Setsubun (節分) is the day before the start of spring, usually around February 3. It's a time for special rituals to chase away bad luck. Another important time is Higan (彼岸), which are seven-day periods around the spring and autumn equinoxes. These are times for remembering ancestors.

Months of the Year

The Japanese calendar used to be based on the Chinese lunar calendar, which meant its months started a bit later than the Gregorian calendar. This is important when looking at historical dates.

Each month has a common Japanese name (like "first month," "second month") and a traditional name. The traditional names are still used in poetry or to add a seasonal touch to greetings. Some, like Yayoi (March) and Satsuki (May), are also popular names for girls.

Here are the months with their common and traditional names:

Dividing the Month

The Week

Japan uses a seven-day week, just like the Western calendar. The names for the days are similar to the Latin system and came to Japan around 800 AD with the Buddhist calendar.

The names of the weekdays in many languages, including Japanese, are based on planets. In East Asia, the five visible planets are named after the five Chinese elements (metal, wood, water, fire, earth).

Sunday and Saturday are usually "take-a-rest days." Sunday has been a full holiday since the late 19th century. Many Japanese shops stay open on weekends because families often visit them then.

10-Day Periods (Jun)

Japanese people also use 10-day periods called jun (旬). Each month is divided into three parts:

• The first 10 days (from the 1st to the 10th) are called jōjun (上旬, upper jun).
• The next 10 days (from the 11th to the 20th) are called chūjun (中旬, middle jun).
• The last days of the month (from the 21st to the end) are called gejun (下旬, lower jun).

These terms are often used to talk about approximate times, like "the weather in the jōjun of April."

Days of the Month

Each day of the month has a specific name. For the first ten days, and for the 20th, the names are unique. After that, the names are more regular, combining numbers with the word for "day." However, in everyday life, people often use regular Arabic numerals (like 1日, 2日, 3日) instead of the traditional names.

For example:

• The 1st day is 一日 (tsuitachi).
• The 2nd day is 二日 (futsuka).
• The 3rd day is 三日 (mikka).
• The 4th day is 四日 (yokka).
• The 10th day is 十日 (tōka).
• The 20th day is 二十日 (hatsuka).

The word tsuitachi originally meant "calendar month start." The last day of the month was traditionally called tsugomori, meaning "moon hidden," from the old lunisolar calendar. New Year's Eve is known as Ōmisoka (大晦日, big 30th).

Some people in Japan believe that certain days are lucky (kichijitsu) or unlucky. For instance, some might avoid starting something new on an unlucky day.

Holidays and Other Special Days

April 1

April 1 is an important day in Japan. It marks the start of the government's financial year, and many companies also begin their new business year on this date. It's also when many new employees start their jobs and the school year begins.

Lucky and Unlucky Days (Rokuyō)

The rokuyō (六曜) are a series of six days that are believed to predict good or bad fortune. You can often find rokuyō on Japanese calendars. People sometimes use them to plan big events like weddings or funerals. However, most people don't pay attention to them in their daily lives.

Here are the six rokuyō days:

National Holidays

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

After World War II, the names of Japan's national holidays were changed to be more general. Many of these holidays have roots in Shinto religion, Buddhism, or important events related to the Japanese imperial family.

If a single day falls between two national holidays, it also becomes a holiday. For example, May 4 is always a holiday. If a national holiday falls on a Sunday, the next weekday (usually Monday) becomes a holiday instead.

Changes to Holidays Over Time

• 1948: Many national holidays were first introduced, including New Year's Day, Coming-of-Age Day, and Children's Day.
• 1966: New holidays like Health and Sports Day, Vernal Equinox Day, and National Foundation Day were added.
• 1985: A rule was made that if a day falls between two national holidays, it also becomes a holiday.
• 1989: After the Shōwa Emperor passed away, his birthday (April 29) was renamed Greenery Day. The new Emperor's Birthday holiday moved to February 23 for Akihito.
• 1995: Marine Day was added as a holiday on July 20.
• 2000, 2003: The "Happy Monday System" moved several holidays to Mondays to create longer weekends.
• 2005, 2007: April 29 was renamed Shōwa Day, and May 4 became the new Greenery Day.
• 2014: Mountain Day was created as a new holiday, starting in 2016.
• 2019: When Naruhito became Emperor, the "Emperor's Birthday" holiday moved to February 23.

Seasonal Festivals (Sekku)

These are five traditional seasonal festivals (節句, sekku) that were made official holidays during the Edo period. Their dates can sometimes be a bit confusing today, with some celebrated on the Gregorian calendar and others using a "one-month delay" system.

• January 7: Jinjitsu (人日), also called Nanakusa no sekku (七草の節句). This is a day to eat a special seven-herb rice porridge for good health.
• March 3: Jōshi (上巳), also called Momo no sekku (桃の節句). This is Girls' Day (Hina matsuri (雛祭り)), where families display special dolls.
• May 5: Tango ((端午)), also called Tango no sekku (端午の節句) or Ayame no sekku (菖蒲の節句). This is traditionally Boys' Day, and it overlaps with the national holiday Children's Day. Families fly koinobori (carp streamers).
• July 7: Shichiseki (七夕), also known as Tanabata or Hoshi matsuri (星祭り). This is the Star Festival, where people write wishes on strips of paper and hang them on bamboo.
• September 9: Chōyō (重陽), also called Kiku no sekku (菊の節句). This is the Chrysanthemum Festival, though it's not as widely celebrated today.

Other important days that are not sekku include:

• January 1: Japanese New Year
• August 15: Obon – a Buddhist festival to honor ancestors.
• December 31: Ōmisoka – New Year's Eve.

Calendar Customs in Modern Japan

The "One-Month Delay" (Tsuki-okure)

Unlike some other East Asian countries, Japan has mostly stopped using the old Chinese calendar for daily life. Since 1876, January has been the "first month" for traditional events too. However, this can sometimes feel a bit off seasonally because the Gregorian calendar is earlier than the old lunar calendar.

To fix this, modern Japanese culture often uses a "compromise" called Tsuki-okure ("One-Month Delay" (月遅れ)) or Chūreki ("The Eclectic Calendar" (中暦)). This means a festival is celebrated one solar calendar month later than its date on the Gregorian calendar. For example, the Obon festival was traditionally on the 15th day of the 7th month. In many places, it's celebrated on July 15. But in other areas, it's celebrated on August 15, which feels more like the original seasonal timing. The only big exception is Japanese New Year, which is always celebrated on January 1.

See also

In Spanish: Calendario japonés para niños

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