Gengō is a traditional Japanese system of era names used to mark years in the calendar. Each era begins with the reign of a new emperor, and the name reflects the spirit or aspirations of that period. For example, the current era, Reiwa, began in 2019 with the ascension of Emperor Naruhito. In Japan, the gengō system is commonly used alongside the Western Gregorian calendar. Official documents, calendars, and cultural references often include both systems. This dual usage helps preserve Japan's historical and cultural identity while also accommodating modern global practices.