ante diem III kalendae Iunoniae (30 May)

The Ludi Tarentini began as a private celebration, vowed by a man for the recovery of his ill children. Three days of stage plays were to be held every hundred years in honor of Dis Pater and Prosepina. Later, with some manipulation of the dates, Augustus converted these in 17 BCE into the Ludi Saeculares. On this day the announcement went out, bidding "all free men to pray and fast." They were to gather at the Temple of Jupiter Optimus Maximus at the Capitolium and in front of the Temple of Diana on the Aventine. The first was probably meant for Roman citizens, and the latter for Latins, as the Temple of Diana had originally been established as a Latin sanctuary. Offerings of first fruit were given, and then a sacrifice was made to determine the approval of the Gods. Festivities began in the evening of the following day.