See: Cassiodorus, Chronica 472 AD: "post XL dies defunctus est. Olybrius autem VII imperii mense vitam peregit" ("40 days later he died. But Olybrius ended his life in the 7th month of his reign"). Between 11 July and 19 August there were exactly 40 days using inclusive counting; Paschale campanum473: "moritur Ricimer XIIII kal. Septem." ("Ricimer died on the 14th day before the kalends of September", i.e. 19 August); Fasti vindobonenses priores472: "defunctus est Ricimer XV kl. Septemb". ("Ricimer died on the 15th day before the kalends of September", i.e. 18 August; probably "XIV" (19 August) is intended).
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See: Cassiodorus, Chronica 472 AD: "post XL dies defunctus est. Olybrius autem VII imperii mense vitam peregit" ("40 days later he died. But Olybrius ended his life in the 7th month of his reign"). Between 11 July and 19 August there were exactly 40 days using inclusive counting; Paschale campanum473: "moritur Ricimer XIIII kal. Septem." ("Ricimer died on the 14th day before the kalends of September", i.e. 19 August); Fasti vindobonenses priores472: "defunctus est Ricimer XV kl. Septemb". ("Ricimer died on the 15th day before the kalends of September", i.e. 18 August; probably "XIV" (19 August) is intended).
Gordon 1966, p. 115. Gordon, C.D. (1966). The Age of Attila: Fifth Century Byzantium and the Barbarians. Ann Arbor, MI: University of Michigan Press. OCLC182501.