Please note that Mommsen uses the AUC chronology (Ab Urbe Condita), i.e. from the founding of the City of Rome. You can use this reference table to have the B.C. dates
From: The History of Rome, by Theodor Mommsen
Translated with the sanction of the author by William Purdie Dickson
Character of the Constitution of Gaius Gracchus
This was the political constitution which Gaius Gracchus projected and, in its most essential points, carried out during the two years of his tribunate (631, 632), without, so far as we can see, encountering any resistance worthy of mention, and without requiring to apply force for the attainment of his ends. The order of sequence in which these measures were carried can no longer be recognized in the confused accounts handed down to us, and various questions that suggest themselves have to remain unanswered. But it does not seem as if, in what is missing, many elements of material importance have escaped us; for as to the principal matters we have quite trustworthy information, and Gaius was by no means, like his brother, urged on further and further by the current of events, but evidently had a well- considered and comprehensive plan, the substance of which he fully embodied in a series of special laws.
Now the Sempronian constitution itself shows very clearly to every one who is able and willing to see, that Gaius Gracchus did not at all, as many good-natured people in ancient and modern times have supposed, wish to place the Roman republic on new democratic bases, but that on the contrary he wished to abolish it and to introduce in its stead a -tyrannis--- that is, in modern language, a monarchy not of the feudal or of the theocratic, but of the Napoleonic absolute, type--in the form of a magistracy continued for life by regular re-election and rendered absolute by an unconditional control over the formally sovereign comitia, an unlimited tribuneship of the people for life.
Do you see any typos or other mistakes? Please let us know and correct them
Reference address : https://www.ellopos.net/elpenor/rome/4-03-revolution-gaius-gracchus.asp?pg=34