Theresa Perez Higuera:
The imagery of the wheel of the year, with its classical references, is the origin of mediaeval versions of the theme, such as the floor mosaics of the Cathedral of Aosta or of San Michele in Pavia, where the zodiac takes the place of the labours of the months. Most importantly, the figure of Christ now takes the place of the Year at the centre; he is shown as Sol de Justitia (the Sun of Justice), who governs the course of time, marking the passing of the months and the seasons. An exceptional example of this is the Gerona Tapestry, dated 1100. In the centre the Pantocrator presides over the universe, represented by Creation scenes from Genesis and by the four winds; surrounding it is a border, partly lost, with the figure of the year (ANNUS) above, in the middle and within a circle, and in the remaining compartments the four Rivers of Paradise, the Sun and Moon in their chariots, the four Seasons, and the twelve Months, which frame the central figure of Christ in his role as Lord of Creation and Lord of Time.
[Medieval Calendars by Theresa Perez Higuera. Weidenfeld & Nicolson: London, 1998]