It appears that in the seventh century five days were added to the Babylonian calendar; they were regarded as unpropi-tious, and people had a superstitious awe of them.
The Assyrian year consisted of 360 days; a decade was called a sarus; a sarus consisted of 3,600
days.18
"The Assyrians, like the Babylonians, had a year composed of lunar months, and it seems that the object of astrological reports which relate to the appearance of the moon and sun was to help to determine and foretell the length of the lunar month. If this be so, the year in common use throughout Assyria must have been lunar. The calendar assigns to each month thirty full days; the lunar month is, however, little more than twenty-nine and a half days."19 "It would hardly be possible for the calendar month and the lunar month to correspond so exactly at the end of the year." 20
Assyrian documents refer to months of thirty days only, and count such months from crescent to crescent.21 Again, as in other countries,
16 Cantor, Vorlesungen iiber Geschichte der Mathematik, I, 92.
1-7 "Sin" in Roscher, Lexikon der griech. und rom. Mythologie, Col. 892.
18Georgius Syncellus, ed. Jacob Goar (Paris, 1652), pp. 17, 32.
18 R. C. Thompson, The Reports of the Magicians and Astrologers of Nineveh
and Babylon in the British Museum, II (1900), xix.
20 Ibid., p. xx.
21 Langdon and Fotheringham, The Venus Tablets of Ammizaduga, pp. 45-46; C. H. W. Johns, Assyrian Deeds and Documents, IV (1923), 333; J. Kohler and A. Ungnad, Assyrische Rechtsurkunden (1913) 258, 3; 263, 5; 649, 5.
WORLDS IN COLLISION 335
it is explicitly the lunar month that is computed by the Assyrian astronomers as equal to thirty days. How could the Assyrian astronomers have adjusted the length of the lunar months to the revolutions of the moon, modern scholars ask themselves, and how could the observations reported to the royal palace by the astronomers have been so consistently erroneous?
The month of the Israelites, from the fifteenth to the eighth century before the present era, was equal to thirty days, and twelve months comprised a year; there is no mention of months shorter than thirty days, nor of a year longer than twelve months. That the month was composed of thirty days is evidenced by Deuteronomy 34 : 8 and
robin-bobin
21 : 13, and Numbers 20 : 29, where mourning for the dead is ordered for "a full month," and is carried on for thirty days. The story of the Flood, as given in Genesis, reckons in months of thirty days; it says that one hundred and fifty days passed between the seventeenth day of the second month and the seventeenth day of the seventh month.22 The composition of this text apparently dates from the time between the Exodus and the upheaval of the days of Uzziah.23
The Hebrews observed lunar months. This is attested to by the fact that the new-moon festivals were of great importance in the days of Judges and Kings.24 "The new moon festival anciently stood at least on a level with that of the Sabbath." 25 As these (lunar) months were thirty days long, with no months of twenty-nine days in between, and as the year was composed of twelve such months, with no additional days or intercalated months, the Bible exegetes could find no way of reconciling the three figures: 354 days, or twelve lunar months of twenty-nine and a half days each; 360 days, or a multiplex of twelve times thirty; and 365K days, the present length of the year.
22 Genesis 7 : 11 and 24; 8 : 4.
23The other variant of the story of the Flood (Genesis 7 : 17; 8 : 6) has the Deluge lasting 40
days instead of 150.
2* I Samuel 20 : 5-6; II Kings 4 : 23; Amos 8 : 5; Isaiah 1 : 13; Hosea 2 : 11; Ezekiel 46 : 1, 3.
In the Bible die montii is called hodesh, or "die new (moon)," which testifies to a lunation of diirty days. 25 J. Wellhausen, Prolegomena to the History of Israel (1885), p. 113.
336 WORLDS IN COLLISION
The Egyptian year was composed of 360 days before it became 365 by the addition of five days.
The calendar of the Ebers Papyrus, a document of the New Kingdom, has a year of twelve months of thirty days each.26
In the ninth year of King Ptolemy Euergetes, or —238, a reform party among the Egyptian priests met at Canopus and drew up a decree; in 1866 it was discovered at Tanis in the Delta, inscribed on a tablet. The purpose of the decree was to harmonize the calendar with the seasons
"according to the present arrangement of the world," as the text states. One day was ordered to be added every four years to the "three hundred and sixty days, and to the five days which were afterwards ordered to be added." 2T
The authors of the decree did not specify the particular date on which the five days were added to the 360 days, but they do say clearly that such a reform was instituted on some date after the period when the year was only 360 days long.
On a previous page I referred to the fact that the calendar of 360 days was introduced in Egypt only after the close of the Middle Kingdom, in the days of the Hyksos. The five epigomena must have been added to the 360 days subsequent to the end of the Eighteenth Dynasty. We have no mention of "five days" in all the numerous inscriptions of the Eighteenth Dynasty; the epigomena or, as the Egyptians called them, "the five days which are above the year," 28 are known from the documents of the seventh and following centuries. The pharaohs of the late dynasties used to write: "The year and the five days." The last day of the year was celebrated, not on the last of the epigomena, but on the thirtieth of Mesori, the twelfth month.29
In the fifth century Herodotus wrote: "The Egyptians, reckoning thirty days to each of the twelve months, add five days in every ye
26 Cf. G. Legge in Recueil de travaux relatifs d la philologie et d VarcMolog egyptiennes et assyriennes (La Mission frangaise du Caire, 1909).
27 S. Sharpe, The Decree of Canopus (1870).
28 E. Meyer, "Agyptische Chronologie," Philos. und hist. Abhandlungen der Preuss. Akademie der Wissenschaften (1904), p. 8.
2» Ibid.
WORLDS IN COLLISION 337
over and above the number, and so the completed circle of seasons is made to agree with the calendar." 30
robin-bobin
The Book of Sothis, erroneously ascribed to the Egyptian priest Manetho,31 and Georgius Syncellus, the Byzantine chronologist,32 maintain that originally the additional five days did not follow the 360 days of the calendar, but were introduced at a later date,33 which is corroborated by the text of the Canopus Decree.
That the introduction of epigomena was not the result of progress in astronomical knowledge, but was caused by an actual change in the planetary movements, is implied in the Canopus Decree, for it refers to "the amendment of the faults of the heaven." In his Isis and Osiris 34
Plutarch describes by means of an allegory the change in the length of the year: "Hermes playing at draughts with the moon, won from her the seventieth part of each of her periods of illumination, and from all the winnings he composed five days, and intercalated them as an addition to the 360 days." Plutarch informs us also that one of these epigomena days was regarded as inauspicious; no business was transacted on that day, and even kings "would not attend to their bodies until nightfall."
The new-moon festivals were very important in the days of the Eighteenth Dynasty. On all the numerous inscriptions of that period, wherever the months are mentioned, they are reckoned as thirty days long. The fact that the new-moon festivals were observed at thirty-day intervals implies that the lunar month was of that duration.
Recapitulating, we find concordant data. The Canopus Decree states that at some period in the past the Egyptian year was only 360 days long, and that the five days were added at some later date; the Ebers Papyrus shows that under the Eighteenth Dynasty the calendar had a year of 360