Japan uses a unique calendar system that is based on two elements: the era of a ruling emperor and the year within his reign. This sets Japan apart from the rest of the world, which mostly uses the Gregorian calendar to keep track as the years pass by.
Today, era names are chosen when a new emperor comes to power, but this is a relatively recent practice that has been added to an ancient and respected imperial tradition.
This article lists everything you need to know about Japan’s era calendar system, from its historical origins, changes over time, and the current naming system.
If you’re planning a trip to Japan, it’s a useful set of knowledge and a great way to begin conversations with people you meet on your travels.
What is the Japanese era name system?
Japan is a constitutional monarchy and it has a democratically-elected parliamentary government. It also has a hereditary monarchy that is led by the head of the imperial family, the emperor (Tennō,天皇).
The Japanese era name system (gengo) is part of the country’s national calendar and it is based on the length of time an emperor reigns.
It is made up of two key elements:
- The Japanese era name that corresponds to the current emperor’s reign (gengō, 元号).
- A number indicating the year within that reign (元 followed by 年, meaning ‘year’).
This means that any given date will have an element that contains the broad era name related to the emperor currently sitting on the imperial seat (皇位, kōi) of the Chrysanthemum Throne, and the year of his reign.
The imperial era name is widely used on official documents like laws, newspapers, calendars, legal documents, and even coins.
Today, most people use a combination of both gengo and Gregorian calendars as a practical way to note the date.
What is Japan’s current era name?
Japan’s current era is known as Reiwa (令和), which translates to ‘beautiful harmony’. It began on May 1, 2019, when the current emperor Naruhito ascended the imperial throne after his father, Emperor Emeritus Akihito, abdicated.
Based on the date of Naruhito’s ascension, the Japanese year (wareki) for 2022 is 4. Therefore, any Gregorian calendar date in 2022 would be written as 令和 4 年 in Japanese.
How are the era names chosen today?
When a new emperor ascends to the imperial seat, a new era name is needed. While the imperial era name is connected to the new emperor, he does not play a role in the selection process.
That honor lies with the parliamentary cabinet, who choose from a list of names suggested by Japanese bureaucrats and scholars.
The name-choosing process is precise and orderly and they need to follow national guidelines based on the Era Name Law.
- Should reflect the highest of Japanese national ideals
- Should consist of two kanji characters
- Should be easy to read and write
- Cannot have been used in a previous imperial era name combination
- Cannot be commonly used in today’s Japanese vernacular.
In practice, the first year of a new era starts the day the emperor assumes the throne and then ends on December 31. From that point on, each year corresponds with the Gregorian calendar.
How were era names chosen in the past?
From the Heian period (794-1185) to the Meiji era (1868-1912), the era names were chosen by various people with power and influence including court nobles such as descendants of scholar statesman Sugawara no Michizane.
Their shortlists were presented to the imperial court and then the emperor made the final decision.
Era names were chosen to recognize significant events, natural disasters, or anniversaries. It was also common practice to change eras according to the first fifth and 58th years of the auspicious sexagenary cycle that was a traditional method for recording time in east Asia.
It was a great honor if the name you devised was chosen and prestigious families kept detailed records of the meanings and sources of the era names that had been adopted.
Modern Japan and the ‘one reign, one era’ name
The tradition of adopting an era name that corresponds to a complete imperial reign has its origins in the relatively recent Meiji era.
The change took place during the reign of Emperor Meiji, 明治天皇 (given-name Mutsuhito), who took the throne in 1867. This was in year 3 of the Keio era (Keiō (慶応).
He proclaimed a new and modern system known as the ‘one emperor, one era’ ( 一世一元, issei-ichigen) name.
From this point onwards, era names would only change when a new emperor ascended the imperial throne.
Since this change in 1868, there have only been five era names, corresponding to their respective emperors:
- Meiji (明治), 1868-1912, Emperor Meiji (Mutsuhito, 睦仁): 45 years
- Taishō (大正), 1912-1926, Emperor Taishō (Yoshihito, 嘉仁): 15 years
- Shōwa (昭和), 1926-1989, Emperor Shōwa (Hirohito, 裕仁): 64 years
- Heisei (平成), 1989-2019, Emperor Emeritus Akihito (Akihito, 明仁): 31 years
- Reiwa (令和), 2019-present, Emperor Naruhito (Naruhito, 徳仁): 2 years and counting
What happens once an emperor dies?
The emperor and his era name are forever connected. After the emperor dies, he is forever known by the name of his era.
For example, the 124th Emperor of Japan, Hirohito, who reigned from 1926 until his death in 1989, ruled during the Shōwa era. Today, he is known as Emperor Shōwa (昭和).
So you want to discuss the Japanese era name system when you’re in Japan?
It is customary that the reigning emperor is referred to as Tennō Heika (天皇陛下), which translates to ‘His Majesty the Emperor’, or Kinjō Tennō (今上天皇), meaning ‘current emperor’.
Japan is a respectful country so it is a good idea to remember that it is considered rude, even in English, to refer to the emperor by his given name or his current era name, as this is only used after he has died.