Calender

[Atilius]

Anyways, didn't the Pontifex Maximus(or someone) just add that extra month whenever his allies were in political power(as Consuls or whatever), and took out the month when his enemies had political power?

Macrobius, Ammianus, Plutarch, Cicero, and others all state or imply that the calendar was manipulated by intercalating days or months. However, regulation of the Roman calendar fell to the College of Pontifices, presided over by the Pontifex Maximus; the matter was not solely in the hands of the PM. Caesar became Pontifex Maximus in 63 BC, yet his reform of the calendar didn't occur until the year 46 BC. (That year had a total of 445 days.) The 17 year gap indicates that his authority as Pontifex Maximus was absolute only after he had secured supreme political power.