Note 3613 — THE JULIAN CALENDAR AND THE CHRONOLOGY OF CAESAR’S INVASIONS OF BRITAIN
Reading edition
To spare the reader the trouble of doing a sum, I give the proof. The 1st of January, 702, fell, as we have already seen (p. 713), on a market-day; therefore, if the 1st of January, 711, did the same, the number of days that elapsed from the 1st of January, 702, to the last day of December, 710, inclusive, must have been divisible by 8. The year 702 contained 378 days; each of the years 703-7 contained 355 days; 708 contained 445; and ex hypothesi 709 and 710 each contained 365. Now 378 + 355 × 5 + 445 + 365 × 2 = 3,328, which is exactly divisible by 8.