Mean lunar month · historical and NASA comparisons

Mean lunar month · historical and NASA comparisons in Calendar measures · summary on Jewish Cosmology.

Jewish Cosmology is an interactive research and educational web application connecting Hebrew dates, traditional Jewish calendar calculations and halachic concepts of time with the observable motions of the Sun, Moon and planets, astronomical seasons and eclipses.

JavaScript is required for the interactive explorers and calculations. The descriptions and navigation remain available without JavaScript.