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
A still more important circumstance was, that, probably on the
institution of the curule aedileship (387) which was from the first
entrusted with the preparation and oversight of the festival,(3) it
lost its extraordinary character and its reference to a special vow
made by the general, and took its place in the series of the ordinary
annually recurring festivals as the first of all.
Nevertheless the
government adhered to the practice of allowing the spectacle proper
--namely the chariot-race, which was the principal performance--to
take place not more than once at the close of the festival. On the
other days the multitude were probably left mainly to furnish
amusement for themselves, although musicians, dancers, rope-walkers,
jugglers, jesters and such like would not fail to make their
appearance on the occasion, whether hired or not But about the year
390 an important change occurred, which must have stood in connection
with the fixing and prolongation of the festival, that took place
perhaps about the same time.