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
Declaration of War by Rome
The senate now had what they wanted; and in the summer of 554 they were able to propose to the comitia a declaration of war "on account of an attack on a state in alliance with Rome." It was rejected on the first occasion almost unanimously: foolish or evil-disposed tribunes of the people complained of the senate, which would allow the citizens no rest; but the war was necessary and, in strictness, was already begun, so that the senate could not possibly recede.
The burgesses were induced to yield by representations and concessions. It is remarkable that these concessions were made mainly at the expense of the allies. The garrisons of Gaul, Lower Italy, Sicily, and Sardinia, amounting in all to 20,000 men, were exclusively taken from the allied contingents that were in active service--quite contrary to the former principles of the Romans.
All the burgess troops, on the other hand, that had continued under arms from the Hannibalic war, were discharged; volunteers alone, it was alleged, were to be enrolled for the Macedonian war, but they were, as was afterwards found, for the most part forced volunteers--a fact which in the autumn of 555 called forth a dangerous military revolt in the camp of Apollonia. Six legions were formed of the men newly called out; of these two remained in Rome and two in Etruria, and only two embarked at Brundisium for Macedonia, led by the consul Publius Sulpicius Galba.
Do you see any typos or other mistakes? Please let us know and correct them
Reference address : https://www.ellopos.net/elpenor/rome/3-08-second-macedonian-war.asp?pg=36