Sentence:  [March, May, Quintilis, and October] also have their <WSD>Nones</WSD> on the seventh, as Numa ordained, because Julius changed nothing about them. As for January, Sextilis, and December, they still have their <WSD>Nones</WSD> on the fifth, though they began to have thirty-one days after Caesar added two days to each, and it is nineteen days from their Ides to the following Kalends, because in adding the two days Caesar did not want to insert them before either the <WSD>Nones</WSD> or the Ides, lest an unprecedented postponement mar religious observance associated with the <WSD>Nones</WSD> or Ides themselves, which have a fixed date. 
Meaning of the word marked with <WSD> tags:  The notional first-quarter day of a Roman month, occurring on the 7th day of the four original 31-day months (March, May, Quintilis or July, and October) and on the 5th day of all other months.