Treatise VIII of al-Bīrūnī’s al-Qanūn al-Mas‘ūdī, which is one of the major works of astronomy produced by the great polymath Abū Rayḥan al-Bīrūnī (d. ca. 1050). It was written in the 1030s under the patronage of Sultan Mas‘ūd of Ghazna (d. 1040), whom al-Bīrūnī dedicated his work to and thus bearing the Sulṭān’s name on the work. The work is intended to be as an astronomical guide book or a reference book for the use of practicing 11th century astronomers and astrologers to solve any of the standard problems of astronomy known at that time. It is a comprehensive work, comprised of eleven treatises on various topics of astronomy including detail calculation and mathematical problems on daylight length, spherical and trigonometric problems, planetary motion and etc.