Etymology

The etymology of "almanac" is hazy. Some sources say it was borrowed into English from the Arabic word al-manakh, citing the "Kitab al-Manakh," a 13th century publication by eminent Moroccan scholar, mathematician and astronomer, Ibn al-Banna al-Marrakushi. However, the ultimate origin of the word is unknown . Both Arabic manah , "to reckon", and Egyptian almenichiata, "the supernatural rulers of the celestial bodies", have been suggested. Most sources do not trace much beyond the Greek and Latinate etymologies, thus ignoring significant evidence of the word's usage in Egyptian or Arabic languages.

Early almanacs

The origin of the almanac can be traced back to ancient Babylonian astronomy, when tables of planetary periods were produced in order to predict lunar and planetary phenomena.

The precursor to the almanac was the Hellenistic astronomical and meteorological calendar, the parapegma, an inscribed stone, the days of the month indicated by movable pegs inserted into bored holes. According to Diogenes Laertius, Parapegma was the title of a book by Democritus. Ptolemy, the Alexandrian astronomer (2nd century) wrote a treatise, Phaseis—"phases of fixed stars and collection of weather-changes" is the translation of its full title—the core of which is a parapegma, a list of dates of seasonally regular weather changes, first appearances and last appearances of stars or constellations at sunrise or sunset, and solar events such as solstices, all organized according to the solar year. With the astronomical computations were expected weather phenomena, composed as a digest of observations made by various authorities of the past. Parapegmata had been composed for centuries. Similar treatises called Zij were later composed in medieval Islamic astronomy.

Ptolemy believed that the astronomical phenomena caused the changes in seasonal weather; his explanation of why there was not an exact correlation of these events was that the physical influences of other heavenly bodies also came into play. Hence for him, weather prediction was a special division of astrology.

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 Azarqueil) 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.