8. A single year also, if the whole twelve months are taken into account, which are made up of thirty days each (for the month that has been kept from of old is that which the revolution of the moon determines), abounds in the number six. For that which six is, in the first order of numbers, which consists of units up to ten, that sixty is in the second order, which consists of tens up to a hundred. Sixty days, then, are a sixth part of the year. Further, if that which stands as the sixth of the second order is multiplied by the sixth of the first order, then we make six times sixty, i.e. three hundred and sixty days, which are the whole twelve months. But since, as the revolution of the moon determines the month for men, so the year is marked by the revolution of the sun; and five days and a quarter of a day remain, that the sun may fulfill its course and end the year; for four quarters make one day, which must be intercalated in every fourth year, which they call bissextile, that the order of time may not be disturbed: if we consider, also, these five days and a quarter themselves, the number six prevails in them. First, because, as it is usual to compute the whole from a part, we must not call it five days, but rather six, taking the quarter days for one day. Next, because five days themselves are the sixth part of a month; while the quarter of a day contains six hours. For the entire day, i.e. including its night, is twenty-four hours, of which the fourth part, which is a quarter of a day, is found to be six hours. So much in the course of the year does the sixth number prevail.
Complete source paragraph · On the Holy Trinity, Chapter 4.—The Ratio of the Single to the Double Comes from the Perfection of the Senary Number. The Perfection of The Senary Number is Commended in the Scriptures. The Year Abounds in The Senary Number.; original source section: Chapter 5, source paragraph 3 · Original source