Tenpō calendar; Japan's last lunisolar calendar (1844–1872)
Historical term for the lunisolar calendar adopted in the late Edo period, replaced by the Gregorian calendar in 1873.
The Tenpō calendar is a lunisolar calendar used in Japan from 1844 to 1872.
Named after the Tenpō era (1830–1844) during which it was compiled. The exact derivation of the calendar system is based on Chinese lunisolar calendar traditions adapted to Japanese needs.