In Rome the Ludi Romani were celebrated from September 5th to the 19th. This two-week festival was the oldest games and were established to celebrated Jupiter Optimus Maximus. In the midst of the festival, on the 13th, a feast is held in honor of the triad of Jupiter, Juno, and Minerva. On that day in 509 B.C.E. a temple to Jupiter the Best and Greatest – for that is the translation of Opitmus Maximus – was dedicated. After the sacrifice a lavish feast was held, with the best possible food and wine, and attended by musicians and entertainment. All the senators would come to feast, and the statues of the three Gods it was held for were brought out of the Temple, dressed in fine clothes, and sat at the table. Jupiter always reclined on a couch but Juno and Minerva were given chairs. (see Classical Living by Frances Berestein P.hD)
Perhaps the 13th would be a good day to hold a Theoxenia banquet in their honor.