The Roman calendar was an important part of Roman religion as it regulated the many religious events intended to conciliate and secure the goodwill and favour of the gods. Each month was outlined with certain kinds of days and specific religious festivals that honoured the gods and united the people within the Roman Empire.
From very early times, the Romans had established a calendar that contained all of their important religious events and gave structure to the religious year and religious state practices. This calendar contained the fixed festivals of different gods set on specific dates, called feriae stativae, as well as festivals that could move without certain time periods, called feriae conceptivae, like our modern day Easter. This original calendar satisfactorily established the dates of all the festivals but did not take into account the differing lengths of the solar and lunar years. In 46 B.C., Julius Caesar attempted to reconcile this problem and issued a new calendar system with a leap year every four years, which we still use today.
Caesar publicised his new calendar by displaying it in public places throughout the empire on stone tablets. Fragments of about forty of these still survive today and provide us with evidence of the proceedings of the Roman religious year. Writings of Ovid also survive which provide evidence of religious festivals marked on the
From these sources of evidence, an understanding of the operation of the