sentences:  The introduction of intercalation marked an important break from Islam, as under the Islamic calendar the practice of intercalation had been specifically prohibited in the Qurʼan.The Báb did not, however, specify where the intercalary days should go.Baháʼu'lláh, who claimed to be the one foretold by the Báb, confirmed and adopted the Badi calendar in the Kitáb-i-Aqdas, his book of laws.