Ab urbe condita
Titus Livius (Livy)
Livy. History of Rome, Volumes 1-2. Roberts, Canon, Rev, translator. London, New York: J. M. Dent and Sons; E. P. Dutton and Co., 1912.
Of course they all knew it, and because they knew it they preferred to obey the Aemilian Law rather than that older one by which the censors were originally appointed, simply because the former was
the last passed by order of the people and also because when two laws contradict each other the later one repeals the earlier.