I’m always forgetting these myself, so this is as much a quick reference for me, as it is for any visitors to this site.

Classical Japan

• Asuka (538-710)
• Nara (710-794)
• Heian (794-1192)

Medieval Japan

• Kamakura (1192-1333)
• Nanboku-chō (1334-1392)
• Muromachi (1392-1573)
• Azuchi-Momoyama (1573-1603)

Early Modern Japan

• Edo (or Tokugawa) (1603-1867)

Modern Japan

• Meiji (1868-1912)
• Taishō (1912-1926)
• Shōwa (1926-1989)
• Heisei (1989-present)