October is the eighth month (after Martius)  and  is famous for the slaying of the October horse on the Ides.

Bacchanalia is the Festival of Dionysius in Greece and was celebrated in Rome until it was banned by government edict. The parties tend to get wild and out of hand.

Armilustrium is the day the army is purified. The army is assembled and reviewed in the Circus Maximus, garlanded with flowers and the trumpets are played as part of the purification rites.

Fontinalia is a festival in honor of Fontus, the god of fountains, springs, and wells. Fontus is the presumed son of Ianus by the nymph Juturna.

Ieiunium Cereris is a fast to Ceres.

Meditrinalia  honors Meditrina, who is the goddess of healing, wine is consumed in her honor as it is considered to have medicinal properties.

Thesmophoria is a Greek festival  honoring  Demeter in which only women participate and men have no part.