The four seasons of the Roman calendar, as described by Marcus Terentius Varro, are different from our seasons, in the sense that they start on days which differ from those that we are using today. In his Books on Agriculture, Varro shows that the Roman seasons started on the Cross Quarter-days instead than on the Quarter-days of the year as it happens today. Besides the classic subdivision in four parts, in the Books on Agriculture we can also find the year divided into eight parts, that is eight seasons having quite different lengths. In our discussion of Varro's seasons we will compare the days he mentions for the separation of seasons to the Cross Quarter- and Quarter-days that we find in Celtic calendars.