Scope and Contents This important work by the Persian polymath Muḥammad b. Aḥmad, who is better known as Abū Rayḥān "al-Bīrūnī" al-Khwārazmī (d. 440 A.H., 1048 C.E.) was written originally in circa 390 A.H. (1000 A.D.). The manuscript has a distinct multi-ethnic and multi-confessional flavour. Al-Bīrūnī, who calculated on the basis of measurements he took in the Punjab plain that the world was round, describes the systems of calculating time used by the known races of the world, and their associated...