<P> The Romans themselves described their first organized year as one with ten fixed months , each of 30 or 31 days . Such a decimal division fit general Roman practice . The four 31 - day months were called `` full '' ( pleni ) and the others `` hollow '' ( cavi ) . Its 304 days made up exactly 38 nundinal cycles . The system is usually said to have left the remaining 50 - odd days of the year as an unorganized `` winter '' , although Licinius Macer 's lost history apparently stated the earliest Roman calendar employed intercalation instead and Macrobius claims the 10 - month calendar was allowed to shift until the summer and winter months were completely misplaced , at which time additional days belonging to no month were simply inserted into the calendar until it seemed things were restored to their proper place . </P>
<P> The Romans themselves described their first organized year as one with ten fixed months , each of 30 or 31 days . Such a decimal division fit general Roman practice . The four 31 - day months were called `` full '' ( pleni ) and the others `` hollow '' ( cavi ) . Its 304 days made up exactly 38 nundinal cycles . The system is usually said to have left the remaining 50 - odd days of the year as an unorganized `` winter '' , although Licinius Macer 's lost history apparently stated the earliest Roman calendar employed intercalation instead and Macrobius claims the 10 - month calendar was allowed to shift until the summer and winter months were completely misplaced , at which time additional days belonging to no month were simply inserted into the calendar until it seemed things were restored to their proper place . </P>
how many months are in the roman calendar
how many months are in the roman calendar
ten fixed months
ten fixed months