What Is the Gengō System?
Japan uses two parallel year-numbering systems: the Western (Gregorian) year and the gengō (元号), or "era name" system, in which years are counted from the start of each emperor's reign. This system has been used continuously since 645 CE and remains deeply embedded in Japanese official documents, media, and daily conversation.
Modern Eras at a Glance
- Meiji (明治): 1868–1912 — Japan's modernization era
- Taishō (大正): 1912–1926
- Shōwa (昭和): 1926–1989 — Japan's longest 20th-century era (64 years)
- Heisei (平成): 1989–2019 — "achieving peace"
- Reiwa (令和): 2019–present — "beautiful harmony"
2025 is Reiwa 7 (令和7年).
How Era Names Are Chosen
Since the postwar constitution, era names change only upon imperial succession (一世一元, ichigen no sei — "one era per reign"). The name is selected by a government committee, approved by the Cabinet, and announced before the new emperor ascends. Era names are traditionally two kanji characters chosen for their auspicious meaning.
Reiwa was announced on April 1, 2019 — the first time the source was the Japanese classics (Man'yōshū poetry anthology) rather than Chinese texts.
Practical Use
The gengō system is used in:
- Official government documents and legal forms
- Driver's licenses, passports, and residence cards
- Newspapers and broadcast media
- Traditional contexts like graves, temples, and calligraphy
Younger generations increasingly use Western years in casual contexts, and many digital systems support both formats.
Era Transitions and Society
The transition to a new era is a major cultural event. The end of Shōwa (1989) and Heisei (2019) were both marked by deep public reflection on the decades those eras represented. Businesses update systems, stationery makers rush to print new calendars, and media run extensive retrospectives.
Before Modern Eras
Before 1868, era names could change at any time — not just at imperial succession — often to mark auspicious events or disasters. Scholars use the sexagenary cycle (干支) alongside era names to precisely date historical records.