written in the Islamic period. Zīj is a specific term for a set of main and auxiliary tables with relevant explanatory sections for handling all astronomical calculations, and its literature represents the substance of achievements in the field of mathematical astronomy in the period in question. The Islamic zīj literature has its origins in the prototypes taken from Indian, pre-Islamic Persian, and Greek sources—especially Claudius Ptolemy’s Almagest and Handy Tables. The subject matter of a typical zīj deals with chronology, trigonometry, spherical astronomy (duration of daylight, celestial coordinates transformation, etc.), solar, lunar, and planetary theories for their longitudinal and latitudinal motions, and related topics such as the planetary stations and retrograde motions, the solar and lunar parallax, the computation of eclipses, the lunar and planetary visibility phenomena, mathematical astrology, and so forth. In 1956, E. S. Kennedy introduced some 130 zīj works known from medieval Islam (but not all extant), together with a concise summary of the main topics discussed in some important ones, which has grown today to about two hundred (King et al. 2001; King and Samsó 2002).
