The Era name or Nengō (年号) naming system

The Japanese do not use a calendar year system as we do in most part of the world but give a different name at each period of reign of each emperor. This system is still used today for official purpose. But it is quite impossible to remember or calculate the actual calendar year specially before Meiji when the emperor has changed every few years. Therefore, from 1603 up to 1867, the Tokugawa period is very often and commonly refered to Edo period. Then we distinguish roughly early, middle or late Edo which are then followed by Meiji and Taisho periods. The denomination early Showa is also often used to cover the first part of Showa reign which was particularly long.

安永 Anei 1772-1781
天明 Tenmei 1781-1789
寛政 Kansei 1789-1801
享和 Kyowa 1801-1804
文化 Bunka 1804-1818
文政 Bunsei 1818-1830
天保 Tenpo 1830-1844
弘化 Kouka 1844-1848
嘉永 Kaei 1848-1854
安政 Ansei 1854-1860
万延 Manei 1860-1861
文 久 Bunkyu 1861-1864
元治 Genji 1864-1865
慶応 Keiou 1865-1868
明治 Meiji 1868-1912
大正  Taisho 1913-1926
昭和 Shouwa 1926-1988
平成 Heisei 1988-2019
Reiwa 2019-today