Previously Unpublished Works, Fascicles VI-VII

was written by Cassiodorus in 562 A. D. (Migne, lxix. 1249) Referring to Jacques Paul Migne's "Patrologia Latina," a massive 19th-century collection of writings by Church Fathers.. It gives the methods of calculating the indiction A 15-year cycle used in the Roman Empire to date documents, epact The age of the moon in days on January 1st, used to harmonize the solar and lunar years, concurrent Days added to the solar cycle to align it with the days of the week, the year of the 19-year and lunar cycles, the date of Easter in March or April, and the day of the week for any day in any year. Isidore of Seville (570–628 A. D.) in his The Origins original: "Origines", book vi, chapter 17, gives the 95-year cycle of Cyril and a short treatise On the Paschal Cycle original: "De Cyclo Paschali". A very important work on the Computus The mathematical science of the calendar was written by Maximus the Confessor in 633 A. D. (Petau, On the Doctrine of Times original: "De Doctrina Temporum", book iii, pp. 170-93) which seems to have had great influence on Spanish calculations. Bede has left us two treatises. On Times original: "De Temporibus" was written in 704 A. D. and was printed in the first edition (vol. ii. 205) of Bede’s works by Pamelius, published at Basle in 1563 A. D. (Migne xc. 277). In it, Bede describes the divisions of time, dating the equinox as the 8th before the Kalends of April original: "8 kal. April" (March 25). He attributes the 19-year cycle to the Council of Nicaea, dividing it into an 8-year period (ogdoad) and an 11-year period (hendecad). The Paschal table is to consist of eight columns (linea literally "lines" or "rows"): the year of the Incarnation, indiction, lunar epact, concurrent, lunar cycle, 14th of the moon, Easter Sunday, and its place in the lunation. The method of finding these is given.

The foundation of all future treatises on the subject is, however, On the Reckoning of Time original: "De Temporum Ratione", written in 725 A. D. (vol. ii. 49, Migne, xc. 293), with a commentary by Britferth of Ramsey written in the eleventh century. It deals in turn with the divisions of time, the zodiac and the moon’s course through it, her place on the first of each month, the length of moonlight, and her effects on living things and the tides. Then follow the consideration of solar phenomena, the 19-year cycle, embolisms Intercalary months added to the lunar calendar to keep it in sync with the solar year, etc., and the date of the Incarnation, epacts, Easter, and the Paschal cycle. In this treatise, Bede shows wide reading and provides much of the learning which embellishes later treatises; some of his sources have not yet been traced. He gives alternative dates for the equinox—the 12th before the Kalends of April original: "12 kal. April" (March 21) on the authority of the forged Anatolius and of the Egyptians, or the 8th before the Kalends of April from the legendary letter of Hippocrates to Antigonus—finally adhering to the date of March 21. Isidore is quoted for the seasons, the forged Cyril for the story of Pachomius and the angel. Bede fixes the date of the Resurrection as the 6th before the Kalends of April original: "6 kal. April" (March 27), but quotes the forged Theophilus for the 8th before the Kalends of April (March 25), finally avowing the impossibility of reconciling all statements. This discussion was the source of many attempts to reconcile the conflicting data with the Dionysian Calendar The calendar system developed by Dionysius Exiguus, which introduced the "Anno Domini" era. Bede drew up a Paschal table from 532 A. D.