238 CE
The year Censorinus wrote On the Birthday, which he counts as the 991st year since the founding of Rome.
238 CE
How the Romans fixed the year
Censorinus, On the Birthday 20–22 (238 CE), in the edition of Friedrich Hultsch (Leipzig, 1867) · 238 CE
secundum quam rationem nisi fallor hic annus, cuius velut index et titulus quidam est V. C. Pii et Pontiani consulatus, ab olympiade prima millensimus est et quartus decimus, ex diebus dumtaxat aestivis, quibus agon Olympicus celebratur; a Roma autem condita nongentensimus nonagensimus primus, et quidem ex Parilibus, unde urbis anni numerantur;
By this reckoning [of Varro's], unless I am mistaken, the present year is the 1,014th since the first Olympiad. This year is marked and named, as it were, by the consulship of those most distinguished men, Pius and Pontianus. Its Olympic count starts from the summer days when the Olympic games are held. It is the 991st year since Rome was founded, counting from the Parilia, the festival from which the city's years are counted.