Victorius of Aquitaine, a countryman of Prosper of Aquitaine and also working in Rome, produced in 457 an Easter Cycle, which was based on the consular list provided by Prosper's Chronicle.
Klinghammer's computus works along the lines of Jean-Baptiste Schwilgué's computus, which was described in the reference books of 1922 and 1992.
•
This mechanism was built in the 1970s by Frédéric Klinghammer (1908–2006) and is nearly a reduced model of the computus found on the Strasbourg cathedral astronomical clock.
All later writers, including Macrobius about 430, Bede in 725, and other medieval computists (calculators of Easter), continued to state that the bissextum (bissextile day) occurred before the last five days of February.
However, 0 had been used as a number in the medieval computus (the calculation of the date of Easter), beginning with Dionysius Exiguus in 525, without being denoted by a numeral (standard Roman numerals do not have a symbol for 0); instead nulla or nullae, genitive of nullus, the Latin word for "none", was employed to denote a 0 value.