After Augustus died, Livia and
Tiberius had dedicated an altar to the Numen of Augustus (Plin. Nat. 12.94
). We know from the Fasti
Praenestini (in C. I. L.
i. p. 312; cf. p. 385) that on
January 17 the Pontiffs, Augurs, Quindecimviri, and Septemviri sacrificed
victims on this altar. On Jan. 21, 22, and 23, theatrical exhibitions were
held in a private theatre erected in front of the palace. These exhibitions
were strictly private, and only the highest nobles and their families
invited (D. C. 56.46
; J. AJ 19.1
; Tac. Ann.
). In the year Caligula was murdered there was just for that year
an extra day added, viz. Jan. 24 (ix. Kal. Febr.): cf. Suet. Cal. 56
; D. C. 59.29
; Joseph. l.c.
In the Calendar of Philocalus (354 A.D.) the
23rd was removed and the 17th to 19th added (C. I. L.
334 and 385).