How Japan counts years by imperial reign and why it still matters
Introduction
Japan uses the Gregorian Calendar for most daily and international purposes, but it also maintains a traditional year-counting system based on imperial eras (gengō). Each era begins when a new emperor ascends the throne, and the year count resets to 1. Japan's current era is Reiwa, which began on 1 May 2019 when Emperor Naruhito ascended.
How the Era System Works
An imperial era is defined by the period of one emperor's reign. The era name (gengō) is chosen by the government and typically consists of two kanji characters expressing an aspirational concept. Reiwa (令和) is often translated as 'beautiful harmony.' Previous recent eras include Shōwa (1926-1989, Emperor Hirohito) and Heisei (1989-2019, Emperor Akihito).
Years within an era are numbered from 1. The year 2026 is Reiwa 8 (R8). Japanese government documents, official forms, and many businesses use the era year alongside the Gregorian year. Bank passbooks, driver's licenses, and court documents typically display era dates.
Historical Depth
The gengō system has been used continuously since 645 CE, making it one of the longest-running calendar systems still in active use. Before the modern era, emperors sometimes changed the era name mid-reign due to auspicious or inauspicious events — natural disasters, epidemics, or military victories. Since the Meiji Restoration in 1868, the rule has been one era per emperor.
National Holidays and the Era System
When a new era begins, the day of accession becomes a public holiday. The end of an era also creates holiday-adjacent occasions: the last day of Heisei (30 April 2019) and the first day of Reiwa (1 May 2019) were both public holidays, creating a ten-day 'Golden Week' extension that year. Japan's Golden Week normally clusters four national holidays between late April and early May.
Traditional Holidays
Japan's fifteen national holidays include several tied to the solar calendar: Vernal Equinox Day (around 20-21 March) and Autumnal Equinox Day (around 22-23 September). These Equinox holidays are officially defined by the National Astronomical Observatory's annual announcement of the exact date, since the equinox does not fall on the same Gregorian date every year. When a national holiday falls on a Sunday, the following Monday becomes a substitute holiday.
Era Changes and Practical Life
An era change creates significant administrative work. Government databases, software systems, and physical forms must all be updated. The 2019 Reiwa transition required extensive preparation by Japan's tech sector. Era awareness also matters for travellers: if you fill in a date on a Japanese government form and use the wrong era year, the form may be rejected.
Conclusion
Japan's imperial era calendar is a living tradition that connects modern bureaucracy to over 1,300 years of continuous historical practice. It coexists comfortably with the Gregorian calendar, serving as a reminder that timekeeping is always also a cultural statement.