Strictly speaking, they are not Tenpo-reki; the, first day of the month and 24 divisions of the old calendar were calculated from the movement of the moon and the sun of modern astronomy, and to the result of which, only the Chijun-ho was applied like Tenpo ho.
これは現代天文学による月と太陽の動きから朔と二十四節気を計算し置閏法のみ天保暦と同じにしたものであり、厳密には天保暦ではない。