:
See also Computus and Epact. The bishop, or another churchman named
Augustalis in Gaul of the 5th century (possibly the 3rd) was the author of a tract
De ratione Paschae, a table or
laterculus on calculating the
Paschal cycle. He is referenced in the
Carthaginian Computus of 455, preserved in an 8th-century
chronographical manuscript in the
cathedral library at Lucca. The table itself is not extant and the description of it is insufficient for reconstruction. Augustalis reckoned that the
Crucifixion took place on 25 March in the year 28, on the 14th
day of the moon. The dating of the
Passion to 28 agrees with that of
Prosper Tiro. The base date of Augustalis's laterculus was the year 213. It covered a hundred years, ending in 312. Augustalis worked with, or is thought sometimes even to have originated, the 84-year
Metonic cycle usually associated, like the date of March 25 for
Easter, with the
Celtic tradition of
Christianity in Gaul and the
Celtic Islands, including
Hibernia (
Ireland) and
Britannia (
Britain). This cycle is characterized by a 14th-year
saltus lunae ("leap" of the moon), a day added to the
epact to reconcile the
lunar year to the
solar (compare
leap year). Although the author of the Carthaginian Computus takes note of Augustalis as a man "of most sainted memory," he points out several errors in his computations. The 19th-century German scholar
Bruno Krusch placed Augustalis in the 3rd century and thought that the
supputatio Romana, an 84-year Roman table, was derived from the table of Augustalis, which he further identified as the "old table" (
vetus laterculus) referenced in a Paschal prologue in a manuscript at Cologne. The "old table" is more often assumed to be the 112-year table of Hippolytus.
Eduard Schwartz criticized the views of Krusch, asserting that the table of Augustalis was never used in Rome and that it represented an "eccentric version" of the 84-year cycle used by the
insular Celtic churches. He places Augustalis in the 5th century. ==See also==