Roman Republic at peace only twice

Oct 2012
In "The Decline and Fall of Roman Britain," Neil Faulkner wrote: "The city was officially at peace only twice in the entire 500-year history of the Republic." Does anyone know when this "twice" was, and how long they lasted? Printed sources much appreciated.
Aug 2019
In old Rome, peace was linked with the closing the gates of the temple of Janus:

Having in this way obtained the crown, Numa prepared to found, as it were, anew, by laws and customs, that City which had so recently been founded by force of arms. He saw that this was impossible whilst a state of war lasted, for war brutalised men. Thinking that the ferocity of his subjects might be mitigated by the disuse of arms, he built the temple of Janus at the foot of the Aventine as an index of peace and war, to signify when it was open that the State was under arms, and when it was shut that all the surrounding nations were at peace. Twice since Numa's reign has it been shut, once after the first Punic war in the consulship of T. Manlius, the second time, which heaven has allowed our generation to witness, after the battle of Actium, when peace on land and sea was secured by the emperor Caesar Augustus.
Livy 1.19.

Also Augustus boasted:
Janus Quirinus, which our ancestors ordered to be closed whenever there was peace, secured by victory, throughout the whole domain of the Roman people on land and sea, and which, before my birth is recorded to have been closed but twice in all since the foundation of the city, the senate ordered to be closed thrice while I was princeps.
Res Gestae of Augustus 13.
Augustus is talking about Numa the king and Manlius the consul. When he closed them after Actium, Rome was still a Republic.