noun
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.
天保暦は、1844年から1872年まで日本で使われた太陰太陽暦である。
The Tenpō calendar is a lunisolar calendar used in Japan from 1844 to 1872.
The Gregorian calendar replaced 天保暦 in 1873 and is the modern solar calendar used in Japan today.
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.