NASA
Nasa: From Stargazers to Starships: The Calendar
A lesson plan that gives an overview of solar and lunar calendars, their history and lore. Also, of the day and the month, and their relations to the rotational period of the Earth and the orbital period of the Moon.For versions in...
Other
Livius: Caesar's Calendar Reform
A selection from Plutarch that highlights Caesar's desire to reform the calendar and how he came about with the changes he enforced.
Institute for Dynamic Educational Advancement
Our Year
The concept of a year in time and the various kinds of year used in human timekeeping are discussed.
Other
Torah.org: Seven Questions About Rosh Hashanah
A question-and-answer fact sheet about Rosh Hashanah that addresses when, why, and how the festival is observed. Tells why the shofar is sounded on this day and why apples dipped in honey are eaten. Also explains the differences between...