Ephemerides, Zijs And Tables

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Ephemerides, Zijs And Tables

The origins of the almanac can be connected to ancient Babylonian astronomy, when tables of planetary periods were produced in order to predict lunar and planetary phenomena. Similar treatises called Zij were later composed in medieval Islamic astronomy. The modern almanac differs from Babylonian.

Ptolemaic and Zij tables in the sense that "the entries found in the almanacs give directly the positions of the celestial bodies and need no further computation", in contrast to the more common "auxiliary astronomical tables" based on Ptolemy's Almagest. The earliest known almanac in this modern sense is the Almanac of Azarqueil written in 1088 by Abū Ishāq Ibrāhīm al-Zarqālī (Latinized as Arzachel) in Toledo, al-Andalus. The work provided the true daily positions of the sun, moon and planets for four years from 1088 to 1092, as well as many other related tables. A Latin translation and adaptation of the work appeared as the Tables of Toledo in the 12th century and the Alfonsine tables in the 13th century.

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