Over at rogueclassicism there is an interesting comment about this date in Roman history. In Roman terms, still found in our breviaries by the way, it is iii nonas octobres, third day before the Nones of October. On this day the mundus was opened. Here is the entry from rogueclassicism:
mundus patet – the mundus was a ritual pit which had a sort of vaulted cover on it. Three times a year the Romans removed this cover (August 24, Oct. 5 and November 8) at which time the gates of the underworld were considered to be opened and the manes (spirits of the dead) were free to walk the streets of Rome.
In the wake of the horrific school shootings, I wonder if the gate to the underworld wasn’t already open.
Take note that in Roman numbering of dates, the Nones are on different days in different months. There is a little mnemonic you can use to keep the dates clear:
In March, July, October, May
the ides fall on the fifteenth day.
Nones on the seventh and all besides
have two less days for Nones and Ides.
So… you will immediate be shouting the obvious, "But Father! But Father! If the Nones are on 7 October and today is 5 October, how can this be iii nonas octobres, the third day before the Nones of October? This is because Romans counted the days themselves. The numbering was inclusive.
More about the interesting word "Nones": the excellent Lewis & Short Dictionary informs us the Nones are
…the fifth day in every month of the year, except March, May, July, and October, in which it was the seventh; the nones, so called because it was the ninth day before the ides,…. After the expulsion of the kings, the marketdays were no longer allowed to fall on the nones, because the people celebrated the nones as the birthday of Servius Tullius, and fear was entertained of a movement on that day in favor of royalty…. No wedding took place either on the nones or on the ides, because the following day was a dies ater, unfavorable for the offering to be made by the bride…. Augustus, for superstitious reasons, avoided undertaking any thing on the nones, (Suet. Aug. 92).
Notice that in Latin the month conforms grammatically to the name for the day?