While much of the world measures time using the Gregorian calendar alone, Japan continues to track the years in a different way.
On official documents like driver’s licenses, bank forms, and government records, dates are often written not as 2019 or 2024, but as Heisei 31 or Reiwa 6. For those unfamiliar with the system, these numbers can feel disorienting at first—detached from the global calendar, but they follow a consistent logic. This is nengo, or era names, a way of marking time that ties each year to the reign of an emperor. It is both historical and immediate, appearing not only in textbooks but in everyday life in Japan.
How Nengo Works
At its core, nengo (年号) is rather simple.
Each year is defined by two elements: the name of the era, and the number of years since that era began. Together, they form the date.
The era name comes first. This might be Meiji, Showa, Heisei, or the current era: Reiwa. Following it is the year number within that era. The first year is often written as gan (元), meaning “origin” or “beginning,” rather than “1.” After that, however, the years progress numerically, followed by nen (年), meaning “year.”
A date, such as Reiwa 6, therefore corresponds to the sixth year of the current era.
In practice, this system runs alongside the Gregorian calendar nowadays. Most people in Japan are familiar with both, switching between them depending on context. International communication tends to rely on Western dating, while domestic and official use often continues to employ era names.
The result is a dual system of timekeeping—one global, one rooted in national tradition.
Origins: From China to Japan
The system on which nengo is based, however, did not originate in Japan.
It can be traced back to China in 140 BC, where imperial era names were used to mark periods of rule and significant events. From there, the concept spread, eventually reaching Japan in the 7th century.
Japan formally adopted the system in 645 AD, during the reign of Emperor Kotoku. The first era name, Taika, was proclaimed in conjunction with the Taika Reform—a series of political and administrative changes that aimed to centralize power under the imperial court, replace clan-based control of land with state ownership, and establish a more formal system of taxation and governance modeled on Chinese institutions.
That being said, the use of era names was not immediately continuous. In the late 7th century, the practice was interrupted, before being permanently reestablished in 701 during the reign of Emperor Monmu. From that point onward, era names have been used continuously up to the present day.
Early nengo, however, functioned somewhat differently from the system seen today.
Before the Meiji period, era names were not tied strictly to the reign of a single emperor. Instead, they were often changed frequently—sometimes within a few years, or even less—based on events, omens, or political considerations. Court officials determined the names, drawing on classical Chinese texts and symbolism.
Era names could reflect a wide range of circumstances. Wado, for example, was declared following the discovery of copper deposits in Chichibu, a mountainous area in present-day Saitama Prefecture. The characters of this era name combine “wa” (和, Japan) and “do” (銅, copper), referencing the event.
Most historical nengo consisted of two kanji, though during parts of the Nara period, four-character names briefly appeared in imitation of Chinese trends. The majority of these eras were relatively short-lived. Most lasted less than a decade, with only a small number extending beyond 10 or 20 years.
This system would change dramatically in the late 19th century.
From Meiji to Reiwa: The Modern Era System
With the start of the Meiji period in 1868, Japan introduced a new rule: one era name per emperor.
This system, known as issei ichigen no sei (one reign, one era), remains in place today. Each emperor’s reign defines a single era, giving the modern system a structure and continuity that earlier periods lacked.
Since the end of the Edo period, five era names have been used in Japan.
Meiji (1868–1912)
The Meiji era began with the accession of Emperor Mutsuhito and marked one of the most profound turning points in Japanese history.
In 1868, the Tokugawa shogunate—Japan’s military government that had ruled for over 250 years—collapsed following the Boshin War, bringing an end to the Edo period. Political power was thereafter formally restored to the emperor in what is known as the Meiji Restoration.
The name Meiji (明治), often translated as “enlightened rule,” reflected the ambitions of this new government. Japan rapidly industrialized, centralized authority, and undertook sweeping reforms in an effort to modernize and avoid the fate of nations that had come under Western control.
Railways were introduced. A national education system was established. Feudal domains were abolished and replaced with prefectures. Western legal, military, and technological systems were adopted at an unprecedented pace.
By the end of the Meiji era, Japan had transformed from a feudal society into a modern industrial state that had begun to assert itself on the global stage.
Taisho (1912–1926)
The Taisho era followed, bringing a period of relative political openness and cultural change.
The name Taisho (大正), meaning “great righteousness” or “great justice,” coincided with a shift in governance. Emperor Taisho’s poor health meant that political power increasingly rested with elected officials and party leaders, giving rise to what is often called “Taisho democracy,” a period marked by the growing influence of political parties, expanded suffrage, and a more active role for the Diet in shaping government policy.
Culturally, the period saw growing urbanization and exposure to global trends. Western fashion, literature, and ideas became more visible, particularly in cities like Tokyo and Osaka. The era is sometimes remembered for its sense of experimentation and transition.
Showa (1926–1989)
The Showa era spans more than six decades and encompasses some of the most dramatic chapters in Japan’s modern history.
Its name Showa (昭和) means “bright harmony.”
The early years of Showa were marked by political instability and a shift toward military influence. The 1931 invasion of Manchuria signaled the beginning of Japan’s push into mainland Asia, followed by the outbreak of the Second Sino-Japanese War in 1937. As the effects of the Great Depression deepened economic strain, military leaders gained increasing control over government policy. This ultimately led Japan into World War II, beginning with the attack on Pearl Harbor in 1941.
The war ended in devastation.
Much of the country had been destroyed in air raids, including the firebombing of Tokyo, and the atomic bombings of Hiroshima and Nagasaki in 1945 brought the conflict to a close. In the aftermath, Japan surrendered and entered a period of occupation under Allied forces. During this time, sweeping reforms were implemented, including land redistribution, the expansion of civil rights, and the adoption of a new constitution that renounced war and redefined the role of the emperor as symbolic rather than political.
What followed was one of the most remarkable economic recoveries of the 20th century. From the 1950s through the 1980s, Japan experienced rapid growth, driven by industrial expansion, technological innovation, and strong export industries. By the 1980s, Japan had become the world’s second-largest economy.
The Showa era thus contains both the country’s most difficult moments and its most dramatic recovery, making it one of the most complex periods to define.
Heisei (1989–2019)
The Heisei era began in 1989 with the accession of Emperor Akihito, following the death of Emperor Showa.
The name Heisei (平成) is often interpreted as “achieving peace,” reflecting hopes for stability after the long and eventful Showa period. Yet the era quickly took on a different character.
In the early 1990s, Japan’s asset bubble collapsed, triggering a prolonged period of economic stagnation known as the Lost Decades. Growth slowed, wages stagnated, and long-standing assumptions about economic stability were challenged.
At the same time, Heisei was marked by significant technological and social change. The rise of the internet, mobile technology, and digital culture reshaped daily life, while globalization connected Japan more closely with the rest of the world. During this period, Japanese pop culture—from anime and manga to video games and fashion—also gained widespread international recognition, becoming an increasingly visible part of Japan’s global presence.
That being said, the era was also defined by major natural disasters, including the 1995 Kobe earthquake and the 2011 Tohoku earthquake and tsunami, events that had lasting national and international impact.
Heisei came to an unusual close in 2019, when Emperor Akihito abdicated—the first abdication in over two centuries—marking a rare, planned transition between eras.
Reiwa (2019–Present)
The current era began in 2019 with the accession of Emperor Naruhito.
The name Reiwa (令和) is often translated as “beautiful harmony,” and is notable for being the first era name derived from a Japanese literary source, the Manyoshu, an ancient anthology of poetry, rather than classical Chinese texts.
Reiwa began with a sense of renewal, but quickly encountered global challenges. The COVID-19 pandemic reshaped daily life, travel, and economic activity, influencing the early identity of the era.
At the same time, the period has been marked by ongoing technological advancement, demographic decline, and changing social expectations.
As with previous eras, its full significance will only become clear over time, as the events that define it continue to unfold.
Nengo in Everyday Life
Despite its long history, nengo is not simply a relic of the past.
It remains a part of daily life in Japan. Dates on driver’s licenses, residence cards, official forms, and many government documents are commonly written using era names. Warranties, receipts, and even some digital systems also use nengo, particularly in domestic contexts.
For residents and long-term visitors, learning to convert between era years and Gregorian dates becomes a practical skill.
At the same time, the system continues to evolve.
Digital platforms, international communication, and global standards have increased the use of the Gregorian calendar, particularly in business contexts. Yet nengo persists, not in opposition to this system, but alongside it.
FAQs about Nengo
Why do era names use specific kanji combinations?
Era names are carefully chosen using kanji drawn from classical literature, often Chinese historical or philosophical texts.
The characters are selected to convey:
- stability
- prosperity
- harmony
- renewal
Modern era names are also screened to avoid:
- difficult readings
- duplication of previous initials
- unintended meanings in Japanese and/or other languages
The goal is to create a name that is both symbolic and practical for everyday use.
Are era names used outside of official documents?
Yes. While most common in official settings, nengo also appears in newspapers, on coins and stamps, warranties, and calendars. That said, many businesses use the Gregorian calendar as well, meaning both systems often exist side by side.
Do era years always start on January 1?
No. Era years begin on the day a new emperor ascends to the throne.
For example, the Reiwa era began on May 1, 2019, meaning:
- Dates before May 1, 2019 → Heisei 31
- Dates after → Reiwa 1
This can make conversions slightly tricky within transition years.
Do any other countries still use a similar system today?
Very few.
While the system originated in China, it is no longer used there in official dating. Today, Japan is the only country that still uses era names extensively in everyday and administrative contexts.
How do you quickly convert to nengo?
The easiest way is to remember when each recent era began.
- Reiwa started in 2019
- Heisei started in 1989
- Showa started in 1926
From there, count forward from the first year of the era.
For example, 2019 is Reiwa 1, so 2024 is Reiwa 6.
In practice, many people simply memorize a few key conversions or use their phone when needed.
