The Computus Runicus was a

runic calendar A Runic calendar (also Rune staff or Runic Almanac) is a perpetual calendar, variants of which were used in Northern Europe until the 19th century. A typical runic calendar consisted of several horizontal lines of symbols, one above the ...

produced in 1328 and found on the Swedish island of

Gotland Gotland (, ; ''Gutland'' in Gutnish), also historically spelled Gottland or Gothland (), is Sweden's largest island. It is also a province, county, municipality, and diocese. The province includes the islands of Fårö and Gotska Sandön to th ...

. A transcription/description of the text - called ''Computus Runicus'' - was published in 1626 by the Danish

physician A physician (American English), medical practitioner (Commonwealth English), medical doctor, or simply doctor, is a health professional who practices medicine, which is concerned with promoting, maintaining or restoring health through th ...

and antiquarian

Ole Worm Ole Worm (13 May 1588 – 31 August 1654), who often went by the Latinized form of his name Olaus Wormius, was a Danish physician, natural historian and antiquary. He was a professor at the University of Copenhagen where he taught Greek, Lat ...

(Olaus Wormius) (1588–1654).

Description

The text consists of the 12 calendar pages and a series of additional pages with detailed explanations for finding information used in the medieval

computus As a moveable feast, the date of Easter is determined in each year through a calculation known as (). Easter is celebrated on the first Sunday after the Paschal full moon, which is the first full moon on or after 21 March (a fixed approxi ...

, including

golden numbers Golden means made of, or relating to gold. Golden may also refer to: Places United Kingdom *Golden, in the parish of Probus, Cornwall *Golden Cap, Dorset *Golden Square, Soho, London *Golden Valley, a valley on the River Frome in Gloucestershir ...

and epacts. The calendar is written in

medieval runes In the history of Europe, the Middle Ages or medieval period lasted approximately from the late 5th to the late 15th centuries, similar to the post-classical period of global history. It began with the fall of the Western Roman Empire an ...

with a gloss in

Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power ...

and some places also in Swedish added by Worm. It follows a standard layout for a Medieval calendar similar to those found in a

book of hours The book of hours is a Christian devotional book used to pray the canonical hours. The use of a book of hours was especially popular in the Middle Ages and as a result, they are the most common type of surviving medieval illuminated manuscrip ...

, with Christian feasts and saint's days. Worm attempted to identify some of the unusual symbols found in the calendar, including one marking fast days and another marking the beginning of the

Zodiac The zodiac is a belt-shaped region of the sky that extends approximately 8° north or south (as measured in celestial latitude) of the ecliptic, the apparent path of the Sun across the celestial sphere over the course of the year. The p ...

months which curiously start on the 18th day of each month instead of the more common 20th or 21st. As with any medieval calendar, there is a column for the golden numbers used in the

Metonic cycle The Metonic cycle or enneadecaeteris (from grc, ἐννεακαιδεκαετηρίς, from ἐννεακαίδεκα, "nineteen") is a period of almost exactly 19 years after which the lunar phases recur at the same time of the year. The rec ...

(to find the date of Easter) and another column for the dominical letters (to find the date of Sunday each week). January 31 and the month of February have an additional column to be used for finding the beginning of

Lent Lent ( la, Quadragesima, 'Fortieth') is a solemn religious observance in the liturgical calendar commemorating the 40 days Jesus spent fasting in the desert and enduring temptation by Satan, according to the Gospels of Matthew, Mark and L ...

, while March and April have an additional column to assist with finding the date of

Easter Easter,Traditional names for the feast in English are "Easter Day", as in the '' Book of Common Prayer''; "Easter Sunday", used by James Ussher''The Whole Works of the Most Rev. James Ussher, Volume 4'') and Samuel Pepys''The Diary of Samuel ...

. The author used a similar system of rune replacements for the Latin letters and Roman numerals as those commonly found in other runic calendars, including the use of the extra runes Arlaug, Tvimadur, and Belgthor to represent the Golden Numbers 17, 18, and 19.

References

External links

Online facsimile of original textComputus Runicus - Traduction française par Jara - Editions du Monolithe
14th-century manuscripts Danish chronicles Gotland Runic manuscripts Medieval runes {{Sweden-hist-stub