Akitu was the ancient Babylonian New Year festival, one of the earliest documented celebrations associated with the renewal of the year.
The festival was held in Mesopotamia and was especially important in Babylon. Its ceremonies honored the chief god Marduk and reaffirmed the king's relationship with the deity and the city. Ritual processions, recitations, offerings, and the display of sacred images formed parts of the observance.
Akitu was tied to the agricultural and seasonal cycle rather than to January 1 in the modern Gregorian calendar. In Babylon, the principal festival occurred in the spring month of Nisanu. That timing reflects the ancient Babylonian calendar and should not be projected directly onto today's fixed civil New Year's date.
The festival is sometimes described too simply as a single ancient party. It was a complex state and religious ceremony whose details changed across periods and cities. Evidence comes from Mesopotamian texts and archaeological research, while modern reconstructions must account for gaps and differences in the surviving sources.