41. The Moon also has its quarter-day
THE RECKONING OF TIME
declare unto you,354 but believed that Terminus should be honoured with divine worship, and sacri¢ces and rites o¡ered to him. But much more wretched are the demented men who, having the promise of the heavenly kingdom, prefer to cling to those things which will earn them punishment in the end, being themselves on the road to destruction, rather than to hasten towards eternal things, like those destined for victory.
41. THE MOON ALSO HAS ITS QUARTER-DAY
While we are on the subject, the computist should remember that the lunation of the month of February has 29 days in the other years, but in leap year is counted as 30 [days long], whether it happens to end before or after the intercalated quarter-day. By the addition of this day, it comes to pass that the lunar year is completed in 355 days if it is common and 385 days if it is embolismic. For it is obvious that the quarter-day of which we are speaking is applicable not only to the course of the Sun, /406/ but also to the course of the Moon. If you refuse to take the Moon's quarter-day into account, and apply to February in leap year a lunar month of the same length as you were wont to do before, it will mean that the fourteenth Moon of Easter will waver, and then the course of the year will reel, and that ever-inviolable state of the 19-year cycle, being more and more perturbed, will be overthrown. Therefore, just as the calculation of the quarter-day in the fourth year (which we call bissextile) dictates, we ought to place on the same line the weekday for the 6th kalends of March, for example the third and the fourth, so that we might then remember to count in the Moon as well (for example, likewise the third and fourth). Take heed with constant zeal, that although we shall cause the Moon of the month of February to have one more day than usual, nonetheless on the ¢rst day of March, the Moon will retain the age it did before, with the sole exception of the 11th year of the 19-year cycle.355 /407/ For we issue a 354 John 8.25.
355 The eleventh year is an exception to the rule that a lunar month ''belongs to'' the calendar month in which it ends. In that year the lunar month of January ends on 1
February, and the lunar month of February ends on 2 March: see Commentary on ch. 20; cf. Jones, BOT 375. If leap year falls on any other year of the 19-year cycle, the extra lunar day is absorbed by the extra calendar day, namely the extra 6th kalends of March, and so the lunar age of 1 March is not a¡ected. But since in year 11, 1 March is still within the lunation of February, that lunation will still be carrying the extra leap-year day on 1
March. Therefore if year 11 is a leap year, the Moon will be 30, not 29 days old on 1 March.
TRANSLATION
particular warning that the quarter-day be attributed to the Moon, lest, being further advanced than it ought to be on the ¢rst day of March, it de£ect the calculated course of the Paschal observance from the correct path.356
By what and how many particles of time this same lunar quarter-day accrues demands more extensive investigation, for the frequent interposition of the embolisms and also the calculation of the ''leap [of the Moon]'' interferes, so that it is impossible to distinguish the whole measure of the lunar course with perfect precision.
356 Bede'ssuggestionthat the computist annotate the solar calendar as a reminder of the additional day to be added to the lunar reckoning was taken up by hundreds of medieval manuscript calendars, whose February pages bear the following admonition: ''Remember in leap year to compute the Moon of February as one of 30 days [the February
Moon was normally ''hollow'', or 29 days], so that the Moon of March will still be one of 30 days, as usual, lest the Easter reckoning waver.'' (Memento quod anno bissextili luna februarii XXX dies computes ut tamen luna martii XXX dies habeat sicut semper habet. ne paschalis lunae ratio uacillet.). For examples, see Wormald, English Kalendars, 45, 59, 87,
101, etc.