Omens based on eclipses, Assyria, 7th century B.C.
London, British Museum, inv. K3561

The 20th tablet in the "Enuma Anu Enlil" series contains omens inferred from eclipses of the Moon. Given that the Babylonian calendar is based on lunar months, eclipses of the Moon can only occur around the middle of the month, between the 12th and 15th day. It was considered a bad omen for the Moon to set or rise during an eclipse. The movement of the shadow over the disc of the Moon was the most important factor in calculating which country would suffer the calamity foretold by the eclipse.