During the cena, the actuarius, “account-keeper”, reads out the acta beginning with the date: “seven days before the kalends of August” (VII. Kalendas Sextiles, 53.2 - July 26th). The month of Sextilis had been renamed Augustus in 8 BCE, and so its usage here is odd.
Is Trimalchio here attempting to sound Republican? Perhaps he is expressing a sense of nostalgia as it concerns his public image. Since the acta is imitative of a public announcement, then, it makes sense that Trimalchio would wish to represent himself in a way that shows traditional republican values
In this way, we see Trimalchio imitating the very figure he erases by making this change. What I mean by this is that the change leads to Augustus being removed from the Roman calendar.
The simple act of using Sextilis instead of Augustus signals to the reader what is missing and there is no mistaking that it is a reference to the Augustus since it was for him specifically the month was renamed. This is one of the many occurrences during the dinner of a charged absence.
