Tags: Holiday.
The Neptunalia was an obscure archaic two-day festival in honour of Neptune as god of waters celebrated at Rome in the heat and drought of summer probably July 23 (Varro De lingua Latina vi.19). It was one of the dies comitiales when committees of citizens could vote on civil or criminal matters. In the ancient calendar this day is marked as Nept. ludi et feriae or Nept. ludi from which Leonhard Schmitz (in Smith see link) concluded that the festival was celebrated with games (ludi).