Almanac

An almanac, once also spelled almanack, is a publication that comes out on a regular schedule and compiles current information on one or more topics. This information is typically arranged by calendar and includes weather forecasts, planting dates for farmers, tide tables, and other data presented in tables. Celestial data and statistics are common, such as sunrise and sunset times, eclipse dates, high and low tide hours, and religious festivals. The contents can be customized for a specific audience, like farmers, sailors, or astronomers.

Origin of the phrase

The word’s origin is uncertain. The earliest known use in a sense similar to today’s is in Latin from 1267, when Roger Bacon used it to refer to a set of tables tracking the movements of heavenly bodies, including the Moon. Some have suggested it comes from a Greek word for calendar, but that Greek term appears only once in ancient texts, in a quote by Eusebius about Coptic Egyptian astrological charts.

It is very unlikely Bacon got the word from this source. One etymology report notes that while the first syllable “al-” and its connection to medieval science suggest an Arabic origin, no convincing Arabic word has been found. Ernest Weekley called the word a puzzle, and Walter William Skeat found an Arabic derivation unsatisfactory. The Oxford English Dictionary states the word has no etymon in Arabic but points circumstantially to a Spanish Arabic form, al-manākh.

The Oxford Dictionary of English says it came via Old French and medieval Latin from Spanish Arabic al-manāk (“the calendar”). The spelling “almanach” also appeared, and Bacon used both. The Arabic word al-munākh originally meant “the place where camels kneel” and later came to mean “climate.” Given the prestige of medieval Arabic astronomy works like the Tables of Toledo and the absence of the word in Arabic, it may have been invented in the West as a pseudo-Arabic term, similar to the alchemical word “alkahest.”

Hemerologies and parapegmata

The earliest texts considered almanacs come from the Near East, dating to the middle of the second millennium BC. These are called hemerologies, from the Greek for “calendar.” One example is the Babylonian Almanac, which listed favorable and unfavorable days with advice. Egyptian lists of good and bad moments, three times daily, also survive.

Many of these predictions were linked to celestial events. The flooding of the Nile, for instance, was expected at the summer solstice, but because the civil calendar had exactly 365 days, the date drifted. The first heliacal rising of Sirius was used to predict the flood, and this practice of linking a star’s appearance to an event apparently spread.

The Greek almanac, called a parapegma, was often an inscribed stone with movable pegs marking days. Written texts also existed; Diogenes Laërtius mentions a book titled Parapegma by Democritus. Ptolemy, the 2nd-century Alexandrian astronomer, wrote Phaseis, whose core was a parapegma listing dates of regular weather changes, star appearances and disappearances at sunrise or sunset, and solar events like solstices, all organized by the solar year. Astronomical computations were paired with expected weather, drawn from past authorities.

Ptolemy believed astronomical phenomena caused seasonal weather changes, but that other heavenly bodies also influenced the outcome, making weather prediction a branch of astrology. Surviving Roman menologia rustica combined solar schedules and agricultural tasks with each month’s tutelary deities and major festivals. By the imperial period, each month was headed with illustrations of its chief astrological signs.