This feature, republished for the Coptic New Year, explores Egypt’s Pharaonic, Coptic, and Islamic calendars as novelist ...

Stonehenge is an astonishingly complex monument, which attracts attention mostly for its spectacular megalithic circle and "horseshoe," built around 2600 BC. Over the years, several theories have been ...

Researchers previously thought the calendar ring on the Antikythera mechanism tracked the ancient Egyptian calendar, but new research suggests it tracked the Greek lunar calendar instead. When you ...

pt. 1. Calendar in theory -- ch. 1. Calendar -- ch. 2. Astronomical background -- ch. 3. Time and the clock -- ch. 4. Writing and libraries -- ch. 5. Numbers and ...