Earth and the Moon

Clocks and Calendars

How does the lunar phase cycle coincide with our modern calendar system?

Though most of our daily lives are scheduled according to the solar calendar—that is, based on the motion of Earth around the Sun—the cycle of lunar phases influences our lives a great deal as well. Many holidays with ancient origins were scheduled according to calendars based on lunar phases, so that is how we still decide the dates of such occasions as Easter, Passover, Hanukah, Ramadan, Diwali, and the Chinese New Year.


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