The Babylonians of the Seleucid period did have extensive tables on the motions of the sun and moon which gave variable velocities and positions. Also special conjunctions and eclipses of sun and moon were either in the data or readily obtained from them. Astronomers could predict the new moon and eclipses to within a few minutes. Their data indicate that they knew the length of the solar or tropical year (the year of the seasons) to be roughly 12 months (from new moon to new moon) and the length of the sidereal year (the time for the sun to regain the same position relative to the stars) to within 4 1/2 minutes.
