[Reprinted from the Proceedings of the Society of Biblical Archæology, January 1892]
Epping and Strassmaier, in their book Astronomisches aus Babylon, have lately translated three small documents, originally inscribed on clay tablets in the second century B.C. From these tablets, we learn that the Babylonians of the above date possessed a very advanced knowledge of the science of astronomy. Into the question of the extent of that knowledge we need not here enter further than to say that it enabled the Babylonian astronomers to draw up almanacs for the ensuing year; almanacs in which the eclipses of the sun and moon, and the times of the new and full moon, were accurately noted, as also the positions of the planets throughout the year. These positions were indicated by the nearness of the planet in question to some star in the vicinity of the ecliptic, and the ecliptic was portioned off into twelve groups, coinciding very closely in position and extent with the twelve divisions of the Zodiac as we now know them.
As to the calendar or mode of reckoning the year, we find that the order and names of the twelve months were as follows: Nisannu (or Nisan), Airu, Simannu, Dûzu, Abu, Ulûlu, Tischritu, Arah-samna, Kislimu, Tebitu, Šabâtu, Adaru.
Of these months Ulûlu and Adaru could be doubled as Ulûlu Sami (the second Elul), and Adaru Arki (the last Adar). The Babylonian years were soli-lunar: that is to say, the year of twelve lunar months, containing three hundred and fifty-four days, was bound to the solar year of three hundred and sixty-five days by intercalating, as occasion required, a thirteenth month.
Out of every eleven years there were seven with twelve months, and four with thirteen months. The first day of the year being, like some of our church festivals, dependent on the time of the new moon, was “moveable” (schwankende). The year, according to the tablets before Epping and Strassmaier, “began with Nisan, hence in the spring.”[1]
[1] “Was den Anfang des Jahres betrifft, so haben wir schon gezeigt, das die seleucidische Aera, wie sie in unseren drei Tafeln vorliegt, ihre Jahre mit dem Nisan, also im Frühjahr begann.” (Epping and Strassmaier, Astronomisches aus Babylon, p. 181).
This is a sketch of the Babylonian calendar in the second century B.C., as drawn from the work of the two learned Germans above-named.
Now we find in the British Museum a great number of trade documents which, according to the Catalogue, “cover a period of over two thousand years.” There are “tablets of the time of Rim-sin, Ḫammurabi, and Samsu-iluna; tablets of the time of the Assyrian supremacy, of the time of the native kings, and of the time of the Persian supremacy; tablets of the times of the Seleucidæ, and the Arsacidæ.”[2]
[2] See Guide to the Nimroud Central Saloon, B.M., 1886. The dates of the rulers mentioned are as follows:—
Rim-sin, about 2,300 B.C.