The beginning of the Sumerian year starts at the Spring Equinox. This turning of the year is called zagmu, “the border of the year.” This is the time to take stock, review personal affairs, and financial accounts. Moreover the Gods are affirmed as the supreme authorities of the cosmos.
For Sumerians, the month is called Barazagar, which is thought to be mean “throne of the sanctuary.” During this month, the statues of the Gods are placed by either side of the Throne of Enlil, This is the time that Enlil holds court. First Offerings are made to the Gods.
The Akiti-Sekinku, “the Festival of Barley Consumption,” starts at the full moon, after the harvest. At this festival, presents of bread and beer (burumai) are given. Offerings are made to Nisaba ((Tashmetum) Goddess of Grain), Nanshe (Goddess of Divination) or Ningirsu (God of the Floods) (depending on the city). On the first day of the festival, the God, their Family, and Associates receive offerings. On the second day, the God receive the most offerings. On the final day, only the God receives any offerings. (These offerings are barley, dates and dark beer.)
From a “Hymn to Nisaba:”
In order to make grain and vegetable grown in the furrow,
So that the excellent corn can be marvelled at,
That is, to provide for the seven great throne-daises
By making vegetables shoot forth, making grain shoot forth,
At harvest, the great festival of Enlil,
She in her great princely role has verily cleansed (her) body,
Has verily put the holy priestly garment on (her) torso.
(N.B. This alludes to the beauty of the grain being harvested.)
The Akitu Festival in Nippur,Sumer honors the coming of Nanna. The entry of Nanna is celebrated, with his statue brought in by barge from the akitu house (a building outside of the city). (The akitu house is where the God temporarily lives while He is on the earth.) Depending on the Sumerian city, Nanna, Ninurta, Enlil or Inanna are celebrated. Modern Sumerian Polytheists usually choose between the four Gods to honor.
Note: The Sumerians had a lunar calendar, and added months beyond the 12-month year. They kept their year keyed to the equinoxes. Modern Sumerian Polytheists follow the reconstructed calendar of the holy city of Nippur.